FM 5-125 - GlobalSecurity.org · FM 5-125 C1 Change 1 Headquarters Department of the Army...

FM 5-125C1

Change 1 HeadquartersDepartment of the Army

Washington, DC, 23 February 2001

Rigging Techniques, Procedures,and Applications

1. Change FM 5-125, 3 October 1995, as follows:

Remove Old Pages Insert New Pages

i through iv i through ivvii and viii vii and viii1-15 through 1-20 1-15 through 1-212-37 through 2-40 2-37 through 2-40

2. A bar ( ) marks new or changed material.

3. File this transmittal sheet in front of the publication.

DISTRIBUTION RESTRICTION: Approved for public release; distribution is unlimited.

ERIC K. SHINSEKI General, United States Army Chief of Staff

Official:

JOEL B. HUDSONAdiministrative Assistant to the Secretary of the Army 0100405

DISTRIBUTION:

Active Army, Army National Guard, and US Army Reserve: To be distributed in accordancewith the initial distribution number 115426, requirements for FM 5-125.

i

Field ManualNo. 5-125

Rigging Techniques,Procedures, and Applications

Contents

Page

LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viiLIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvPREFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii

Chapter 1. RopeSection I. Fiber Rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Types of Fibers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1Vegetable Fibers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1Synthetic Fibers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Characteristics of Fiber Rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Care of Fiber Rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Handling of Fiber Rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5Inspection of Fiber Rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Section II. Wire Rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6Types of Wire-Rope Cores. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Fiber-Rope Cores . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7Independent Wire-Rope Cores. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7Wire-Strand Cores . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

DISTRIBUTION RESTRICTION: Approved for public release; distribution is unlimited.*This manual supersedes TM 5-725, 3 October 1968.

*FM 5-125

HeadquartersDepartment of the Army

Washington, DC, 3 October 1995

ii

FM 5-125

PageClassification of Wire Rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Wire and Strand Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7Lay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Characteristics of Wire Rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

Care of Wire Rope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10Reversing or Cutting Back Ends. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11Lubricating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11Storing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11

Handling of Wire Rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11Kinking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12Coiling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12Unreeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12Seizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12Welding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14Cutting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14Drums and Sheaves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15

Inspection of Wire Rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20Causes of Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21

Chapter 2. Knots, Splices, Attachments, and LaddersSection I. Knots, Hitches, and Lashings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Knots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Knots at the End of Rope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4Knots for Joining Two Ropes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5Knots for Making Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6Knots for Tightening a Rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12Knots for Wire Rope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

Hitches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17Half Hitch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17Two Half Hitches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17Round Turn and Two Half Hitches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18Timber Hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18Timber Hitch and Half Hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18Clove Hitch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

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PageRolling Hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18Telegraph Hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19Mooring Hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19Scaffold Hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19Blackwall Hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19Harness Hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22Girth Hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22Sheepshank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23Fisherman's Bend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

Lashings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24Square Lashing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24Shears Lashing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24Block Lashing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26

Section II. Splices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26Fiber-Rope Splices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26

Short Splice 2-26Eye or Side Splice. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26Long Splice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28Crown or Back Splice. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28

Wire-Rope Splices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31Short Splice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31Eye or Side Splice. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31Long Splice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32

Section III. Attachments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34End Fittings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35

Clips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35Clamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37

Wedge Socket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37Basket-Socket End Fitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37

Poured Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37Stanchions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40

Section IV. Rope Ladders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-41Hanging Ladders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-41

Wire-Rope Ladders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-41Fiber-Rope Ladders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43

Standoff Ladders. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45

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Chapter 3. HoistsSection I. Chains and Hooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1Strength of Chains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Care of Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Hooks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3Strength of Hooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3Mousing of Hooks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Inspection of Chains and Hooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Section II. Slings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Types of Slings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5Endless Slings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5Single Slings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6Combination Slings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

Pallets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8Spreaders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8Stresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9Inspecting and Cushioning Slings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

Section III. Blocks and Tackle Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

Types of Blocks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14Reeving of Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16

Tackle Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18Simple Tackle Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18Compound Tackle Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18Friction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20

Section IV. Chain Hoists and Winches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22Chain Hoists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22

Types of Chain Hoists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22Load Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23

Winches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24Ground Angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24Fleet Angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24Spanish Windlass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25

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List of Figures

Page

Figure 1-1. Cordage of rope construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l-2

Figure 1-2. Uncoiling and coiling rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Figure 1-3. Elements of wire-rope construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Figure 1-4. Arrangement of strands in wire rope . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Figure 1-5. Wire-rope lays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Figure 1-6. Measuring wire rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

Figure 1-7. Kinking in wire rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12

Figure 1-8. Unreeling wire rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13

Figure 1-9. Uncoiling wire rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13

Figure 1-10. Seizing wire rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14

Figure 1-11. Wire-rope cutter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15

Figure 1-12. Avoiding reverse bends in wire rope . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17

Figure 1-13. Spooling wire rope from reel to drum . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17

Figure 1-14. Determining starting flange of wire rope . . . . . . . . . . . . . . . . . . . . . . 1-18

Figure 1-15. Winding wire-rope layers on a drum. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19

Figure 1-16. Lay length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20

Figure 1-17. Unserviceable wire rope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21

Figure 2-1. Elements of knots, bends, and hitches . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Figure 2-2. Whipping the end of a rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Figure 2-3. Overhand knot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Figure 2-4. Figure-eight knot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Figure 2-5. Wall knot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Figure 2-6. Crown on a wall knot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Figure 2-7. Square knot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

Figure 2-8. Single sheet bend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

Figure 2-9. Double sheet bend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Figure 2-10. Carrick bend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Figure 2-11. Bowline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

Figure 2-12. Double bowline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

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Figure 2-13. Running bowline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

Figure 2-14. Bowline on a bight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

Figure 2-15. Spanish bowline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

Figure 2-16. French bowline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

Figure 2-17. Speir knot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

Figure 2-18. Cat's-paw. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

Figure 2-19. Figure eight with an extra turn. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

Figure 2-20. Butterfly knot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

Figure 2-21. Baker bowline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15

Figure 2-22. Half hitches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

Figure 2-23. Round turn and two half hitches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

Figure 2-24. Timber hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

Figure 2-25. Timber hitch and half hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

Figure 2-26. Clove hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19

Figure 2-27. Rolling hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

Figure 2-28. Telegraph hitch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

Figure 2-29. Mooring hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

Figure 2-30. Scaffold hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

Figure 2-31. Blackwall hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22

Figure 2-32. Harness hitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22

Figure 2-33. Girth hitch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

Figure 2-34. Sheepshank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

Figure 2-35. Fisherman's bend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24

Figure 2-36. Square lashing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

Figure 2-37. Shears lashing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

Figure 2-38. Block lashing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26

Figure 2-39. Renewing rope strands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27

Figure 2-40. Short splice for fiber rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27

Figure 2-41. Eye or side splice for fiber rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28

Figure 2-42. Long splice for fiber rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-29

Figure 2-43. Crown or back splice for fiber rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30

Figure 2-44. Tools for wire splicing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32

Figure 2-45. Tucking wire-rope strands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32

Figure 2-46. Eye splice with thimble for wire rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33

Figure 2-47. Hasty eye splice for wire rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33

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L i s t o f T a b l e s

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P r e f a c e

This manual is a guide and basic reference for personnel whose duties require the use of rig-ging. It is intended for use in training and as a reference manual for field operations. It cov-ers the types of rigging and the application of fiber rope, wire rope, and chains used invarious combinations to raise or move heavy loads. It includes basic instructions on knots,hitches, splices, lashing, and tackle systems. Safety precautions and requirements for thevarious operations are listed, as well as rules of thumb for rapid safe-load calculations.

The material contained herein is applicable to both nuclear and nonnuclear warfare.

The proponent for this publication is Headquarters (HQ), United States (US) Army Train-ing and Doctrine Command (TRADOC). Users of this manual are encouraged to submit rec-ommended changes or comments on Department of the Army (DA) Form 2028 and forwardthem to: Commandant, US Army Engineer School, ATTN: ATSE-T-PD-P, Fort LeonardWood, Missouri 65473-6500.

Unless otherwise stated, masculine nouns and pronouns do not refer exclusively to men.

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C H A P T E R 1

R o p e

Section 1. Fiber Rope

In the fabrication of fiber rope, a numberof fibers of various plants are twistedtogether to form yarns. These yarns arethen twisted together in the opposite direc-tion of the fibers to form strands (see Figure1-1, page 1-2). The strands are twisted inthe opposite direction of the yarns to formthe completed rope. The direction of twist ofeach element of the rope is known as the“lay” of that element. Twisting each element

TYPES OF

The term cordage is applied collectively toropes and twines made by twisting togethervegetable or synthetic fibers.

VEGETABLE FIBERSThe principal vegetable fibers are abaca(known as Manila), sisalana and henequen(both known as sisal), hemp, and some-times coir, cotton, and jute. The last threeare relatively unimportant in the heavycordage field.Abaca, sisalana, and henequen are classi-fied as hard fibers. The comparativestrengths of the vegetable fibers, consider-ing abaca as 100, are as follows:

Sisalana 80

Henequen 65

Hemp 100

in the opposite direction puts the rope inbalance and prevents its elements fromunlaying when a load is suspended on it.The principal type of fiber rope is thethree-strand, right lay, in which threestrands are twisted in a right-hand direc-tion. Four-strand ropes, which are alsoavailable, are slightly heavier but areweaker than three-strand ropes of thesame diameter.

FIBERS

ManilaThis is a strong fiber that comes from theleaf stems of the stalk of the abaca plant,which belongs to the banana family. Thefibers vary in length from 1.2 to 4.5 meters(4 to 15 feet) in the natural states. Thequality of the fiber and its length giveManila rope relatively high elasticity,strength, and resistance to wear and dete-rioration. The manufacturer treats therope with chemicals to make it more mil-dew resistant, which increases the rope’squality. Manila rope is generally the stan-dard item of issue because of its qualityand relative strength.

SisalSisal rope is made from two tropicalplants, sisalana and henequen, that pro-duce fibers 0.6 to 1.2 meters (2 to 4 feet)

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long. Sisalana produces the stronger fibers yarn. Since hemp absorbs much betterof the two plants, so the rope is known assisal. Sisal rope is about 80 percent asstrong as high quality Manila rope and canbe easily obtained. It withstands exposureto sea water very well and is often used forthis reason.

HempThis tall plant is cultivated in many parts ofthe world and provides useful fibers formaking rope and cloth. Hemp was usedextensively before the introduction ofManila, but its principal use today is in fit-tings, such as ratline, marline, and spun

than the hard fibers, these fittings areinvariably tarred to make them morewater-resistant. Tarred hemp has about80 percent of the strength of untarredhemp. Of these tarred fittings, marline isthe standard item of issue.

Coir and CottonCoir rope is made from the fiber of coconuthusks. It is a very elastic, rough ropeabout one-fourth the strength of hemp butlight enough to float on water. Cottonmakes a very smooth white rope that with-stands much bending and running. These

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two types of rope are not widely used in themilitary; however, cotton is used in somecases for very small lines.

JuteJute is the glossy fiber of either of two EastIndian plants of the linden family usedchiefly for sacking, burlap, and cheaper vari-eties of twine and rope.

SYNTHETIC FIBERSThe principal synthetic fiber used for ropeis nylon. It has a tensile strength nearlythree times that of Manila. The advantageof using nylon rope is that it is waterproofand has the ability to stretch, absorbshocks, and resume normal length. It alsoresists abrasion, rot, decay, and fungusgrowth.

CHARACTERISTICS OF FIBER ROPE

Fiber rope is characterized by its size,weight, and strength.

SIZEFiber rope is designated by diameter up to5/8 inch, then it is designated by circumfer-ence up to 12 inches or more. For this rea-son, most tables give both the diameter andcircumference of fiber rope.

WEIGHT

The weight of rope varies with use, weatherconditions, added preservatives, and otherfactors. Table 1-1, page 1-4, lists the weightof new fiber rope.

STRENGTH

Table 1-1 lists some of the properties ofManila and sisal rope, including the break-ing strength (B S), which is the greateststress that a material is capable of with-standing without rupture. The table showsthat the minimum BS is considerablygreater than the safe load or the safe work-ing capacity (SWC). This is the maximumload that can safely be applied to a particu-lar type of rope. The difference is caused bythe application of a safety factor. To obtain

the SWC of rope, divide the BS by a factorof safety (FS):

SWC = BS/FSA new l-inch diameter, Number 1 Manilarope has a BS of 9,000 pounds (seeTable 1-1). To determine the rope’s SWC,divide its BS (9,000 pounds) by a minimumstandard FS of 4. The result is a SWC of2,250 pounds. This means that you cansafely apply 2,250 pounds of tension to thenew l-inch diameter, Number 1 Manilarope in normal use. Always use a FSbecause the BS of rope becomes reducedafter use and exposure to weather condi-tions. In addition, a FS is required becauseof shock loading, knots, sharp bends, andother stresses that rope may have to with-stand during its use. Some of thesestresses reduce the strength of rope asmuch as 50 percent. If tables are not avail-able, you can closely approximate the SWCby a rule of thumb. The rule of thumb forthe SWC, in tons, for fiber rope is equal tothe square of the rope diameter (D) ininches:

SWC = D2

The SWC, in tons, of a l/2-inch diameterfiber rope would be 1/2 inch squared or 1/4ton. The rule of thumb allows a FS ofabout 4.

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CARE OF FIBER ROPE

The strength and useful life of fiber rope isshortened considerably by improper care.To prolong its life and strength, observe thefollowing guidelines:

Ensure that it is dry and then stored ina cool, dry place. This reduces the possibility of mildew and rotting.

Coil it on a spool or hang it from pegsin a way that allows air circulation.

Avoid dragging it through sand or dirtor pulling it over sharp edges. Sand or

grit between the fibers cuts them andreduces the rope’s strength.

Slacken taut lines before they areexposed to rain or dampness becausea wet rope shrinks and may break.Thaw a frozen rope completely beforeusing it; otherwise the frozen fiberswill break as they resist bending.Avoid exposure to excessive heat andfumes of chemicals; heat or boilingwater decreases rope strength about20 percent.

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HANDLING OF FIBER ROPE

New rope is coiled, bound, and wrapped in the end of the rope. This should be at theburlap. The protective covering should not bottom of the coil (see Figure 1-2). If it isbe removed until the rope is to be used. This not, turn the coil over so the end is at theprotects it during storage and prevents tan- bottom. Pull the end up through the centergling. To open the new rope, strip off the of the coil. As the rope comes up, it unwindsburlap wrapping and look inside the coil for in a counterclockwise direction.

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INSPECTION OF FIBER ROPEThe outside appearance of fiber rope is notalways a good indication of its internal con-dition. Rope softens with use. Dampness,heavy strain, fraying and breaking ofstrands, and chafing on rough edges allweaken it considerably. Overloading ropemay cause it to break, with possible heavydamage to material and serious injury topersonnel. For this reason, inspect it care-fully at regular intervals to determine itscondition. Untwist the strands slightly toopen a rope so that you can examine theinside. Mildewed rope has a musty odorand the inner fibers of the strands have adark, stained appearance. Broken strands

or broken yarns ordinarily are easy to iden-tify. Dirt and sawdust-like material inside arope, caused by chafing, indicate damage.In rope having a central core, the coreshould not break away in small pieces whenexamined. If it does, this is an indicationthat a rope has been overstrained.If a rope appears to be satisfactory in allother respects, pull out two fibers and try tobreak them. Sound fibers should offer con-siderable resistance to breakage. When youfind unsatisfactory conditions, destroy arope or cut it up in short pieces to preventits being used in hoisting. You can use theshort pieces for other purposes.

Section II. Wire RopeThe basic element of wire rope is the individ- usually wound or laid together in the oppositeual wire, which is made of steel or iron in vari- direction of the lay of the strands. Strandsous sizes. Wires are laid together to form are then wound around a central core thatstrands, and strands are laid together to form supports and maintains the position of-rope (see Figure 1-3). Individual wires are strands during bending and load stresses.

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In some wire ropes, the wires and strands completed rope. As a result, preformed wireare preformed. Preforming is a method of rope does not contain the internal stressespresetting the wires in the strands (and the found in the nonpreformed wire rope; there-strands in the rope) into the permanent heli- fore, it does not untwist as easily and iscal or corkscrew form they will have in the more flexible than nonpreformed wire rope.

TYPES OF WIRE ROPE CORESThe core of wire rope may be constructed offiber rope, independent wire rope, or a wirestrand.

FIBER-ROPE CORESThe fiber-rope core can be of vegetable orsynthetic fibers. It is treated with a speciallubricant that helps keep wire rope lubri-cated internally. Under tension, wire ropecontracts, forcing the lubricant from the coreinto the rope. This type of core also acts as acushion for the strands when they are understress, preventing internal crushing of indi-vidual wires. The limitations of fiber-ropecores are reached when pressure, such ascrushing on the drum, results in the collapse

CLASSIFICATION

Wire rope is classified by the number ofstrands, the number of wires per strand, thestrand construction, and the type of lay.

WIRE AND STRAND COMBINATIONSWire and strand combinations vary accord-ing to the purpose for which a rope isintended (see Figure 1-4, page 1-8). Ropewith smaller and more numerous wiresis more flexible; however, it is less resistantto external abrasion. Rope made up of asmaller number of larger wires is more resis-tant to external abrasion but is less flexible.The 6-by-37 wire rope (6 strands, each madeup of 37 wires) is the most flexible of thestandard six-strand ropes. This flexibilityallows it to be used with small drums andsheaves, such as on cranes. It is a very efficient

of the core and distortion of the rope strand.Furthermore, if the rope is subjected toexcessive heat, the vegetable or syntheticfibers may be damaged.

INDEPENDENT, WIRE-ROPE CORES

Under severe conditions, an independent,wire-rope core is normally used. This isactually a separate smaller wire rope thatacts as a core and adds strength to the rope.

WIRE-STRAND CORESA wire-strand core consists of a singlestrand that is of the same or a more flexibleconstruction than the main rope strands.

OF WIRE ROPE

rope because many inner strands are pro-tected from abrasion by the outer strands.The stiffest and strongest type for generaluse is the 6-by-19 rope. It may be used oversheaves of large diameter if the speed iskept to moderate levels. It is not suitablefor rapid operation or for use over smallsheaves because of its stiffness. The 6-by-7wire rope is the least flexible of the stan-dard rope constructions. It can withstandabrasive wear because of the large outerwires.

LAY

Lay refers to the direction of winding ofwires in strands and strands in rope (seeFigure 1-5, page 1-8). Both may be wound inthe same direction, or they may be wound in

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opposite directions. The three types of ropelays are—

Regular.

Lang.

Reverse.

Regular LayIn regular lay, strands and wires are woundin opposite directions. The most common layin wire rope is right regular lay (strandswound right, wires wound left). Left regularlay (strands wound left, wires wound right)is used where the untwisting rotation of therope counteracts the unscrewing forces in

the supported load, such as in drill rods andtubes for deep-well drilling.

Lang LayIn lang lay, strands and wires are wound inthe same direction. Because of the greaterlength of exposed wires, lang lay assureslonger abrasion resistance of wires, lessradial pressure on small diameter sheavesor drums by rope, and less binding stressesin wire than in regular lay wire rope. Disad-vantages of lang lay are its tendencies tokink and unlay or open up the strands,which makes it undesirable for use wheregrit, dust, and moisture are present. Thestandard direction of lang lay is right(strands and wires wound right), although italso comes in left lay (strands and wireswound left).

Reverse LayIn reverse lay, the wires of any strand arewound in the opposite direction of the wiresin the adjacent strands. Reverse lay appliesto ropes in which the strands are alternatelyregular lay and lang lay. The use of reverselay rope is usually limited to certain types ofconveyors. The standard direction of lay isright (strands wound right), as it is for bothregular-lay and lang-lay ropes.

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CHARACTERISTICS OF WIRE ROPEWire rope is characterized by its size,weight, and strength.

SIZEThe size of wire rope is designated by itsdiameter in inches. To determine the size ofa wire rope, measure its greatest diameter(see Figure 1-6).

WEIGHTThe weight of wire rope varies with the sizeand the type of construction. No rule ofthumb can be given for determining theweight. Approximate weights for certainsizes are given in Table 1-2, page 1-10.

STRENGTHThe strength of wire rope is determined byits size and grade and the method of fabrica-tion. The individual wires may be made ofvarious materials, including traction steel,mild plow steel (MPS), improved plow steel(IPS), and extra IPS. Since a suitable margin

of safety must be provided when applying aload to a wire rope, the BS is divided by anappropriate FS to obtain the SWC for thatparticular type of service (see Table 1-3,page 1-11).You should use the FS given in Table 1-3 inall cases where rope will be in service for aconsiderable time. As a rule of thumb, youcan square the diameter of wire rope in,inches, and multiply by 8 to obtain the SWCin tons:

SWC = 8D2

A value obtained in this manner will notalways agree with the FS given in Table 1-3.The table is more accurate. The proper FSdepends not only on loads applied but alsoon the—

Speed of the operation.

Type of fittings used for securing therope ends.

Acceleration and deceleration.

Length of the rope.

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Number, size, and location of sheaves Possible loss of life and property if theand drums. rope fails.Factors causing abrasion and corrosion. Table 1-2 shows comparative BS of typicalFacilities for inspection. wire ropes.

CARE OF WIRE ROPE

Caring for wire rope properly includes and storing it. When working with wirereversing the ends and cleaning, lubricating, rope, you should wear work gloves.

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REVERSING OR CUTTING BACK ENDS

To obtain increased service from wire rope,it is sometimes advisable to either reverse orcut back the ends. Reversing the ends ismore satisfactory because frequently thewear and fatigue on rope are more severe atcertain points than at others. To reverse theends, detach the drum end of the rope fromthe drum, remove the rope from the endattachment, and place the drum end of therope in the end attachment. Then fasten theend that you removed from the end attach-ment to the drum. Cutting back the end hasa similar effect, but there is not as muchchange involved. Cut a short length off theend of the rope and place the new end in thefitting, thus removing the section that hassustained the greatest local fatigue.

CLEANING

Scraping or steaming will remove most ofthe dirt or grit that may have accumulated

on a used wire rope. Remove rust at regu-lar intervals by using a wire brush. Alwaysclean the rope carefully just before lubricat-ing it. The object of cleaning at that time isto remove all foreign material and oldlubricant from the valleys between thestrands and from the spaces between theouter wires to permit the newly appliedlubricant free entrance into the rope.

LUBRICATINGAt the time of fabrication, a lubricant isapplied to wire rope. However, this lubri-cant generally does not last throughout thelife of the rope, which makes relubricationnecessary. To lubricate, use a good grade ofoil or grease. It should be free of acids andalkalis and should be light enough to pene-trate between the wires and strands. Brushthe lubricant on, or apply it by passing therope through a trough or box containing thelubricant. Apply it as uniformly as possiblethroughout the length of the rope.

STORING

If wire rope is to be stored for any length oftime, you should always clean and lubri-cate it first. If you apply the lubricant prop-erly and store the wire in a place that isprotected from the weather and from chem-icals and fumes, corrosion will be virtuallyeliminated. Although the effects of rustingand corrosion of the wires and deteriorationof the fiber core are difficult to estimate, itis certain that they will sharply decreasethe strength of the rope. Before storing,coil the rope on a spool and tag it properlyas to size and length.

HANDLING OF WIRE ROPEHandling wire rope may involve kinking, coil- handling wire rope, you should wearing, unreeling, seizing, welding, cutting, work gloves.or the use of drums and sheaves. When

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KINKING

When handling loose wire rope, small loopsfrequently form in the slack portion (see Fig-ure 1-7). If you apply tension while theseloops are in position, they will notstraighten out but will form sharp kinks,resulting in unlaying of the rope. Youshould straighten out all of these loopsbefore applying a load. After a kink hasformed in wire rope, it is impossible toremove it. Since the strength of the rope isseriously damaged at the point where a kinkoccurs, cut out that portion before using therope again.

COILINGSmall loops or twists will form if rope isbeing wound into the coil in a direction thatis opposite to the lay. Coil left-lay wire ropein a counterclockwise direction and right-lay wire rope in a clockwise direction.

UNREELING

When removing wire rope from a reel orcoil, it is imperative that the reel or coilrotate as the rope unwinds. Mount the reelas shown in Figure 1-8. Then pull the ropefrom the reel by holding the end of the ropeand walking away from the reel, whichrotates as the rope unwinds. If wire rope isin a small coil, stand the coil on end and rollit along the ground (see Figure 1-9). If loopsform in the wire rope, carefully removethem before they form kinks.

SEIZINGSeizing is the most satisfactory method ofbinding the end of a wire rope, althoughwelding will also hold the ends together sat-isfactorily. The seizing will last as long asdesired, and there is no danger of weaken-ing the wire through the application of heat.Wire rope is seized as shown in Figure 1-10,page 1-14. There are three convenient rulesfor determining the number of seizings,lengths, and space between seizings. Ineach case when the calculation results in afraction, use the next larger whole num-ber. The following calculations are based ona 4-inch diameter wire rope:

The number of seizings to be appliedequals approximately three times thediameter of the rope (number of seiz-ings = SD).

Example: 3 x 3/4 (D) = 2 1/4. Use 3seizings.

Each seizing should be 1 to 1 1/2 timesas long as the diameter of the rope.(length of seizing= 1 1/2D).

The seizings should be spaced a dis-tance apart equal to twice the diameter(spacing = 2D).

Example: 2 x 3/4 (D) = 1 1/2. Use 2-inchspaces.

1-12 Rope

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Rope 1-13

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Note: Always change the fractionto the next larger whole number.

WELDINGYou can bind wire-rope ends together by fus-ing or welding the wires. This is a satisfac-tory method if you do it carefully, as it doesnot increase the size of the rope and requireslittle time to complete. Before welding rope,cut a short piece of the core out of the end sothat a clean weld will result and the corewill not be burned deep into the rope. Keepthe area heated to a minimum and do not

apply more heat than is essential to fuse themetal.

CUTTINGYou can cut wire rope with a wire-rope cut-ter, a cold chisel, a hacksaw, bolt clippers, oran oxyacetylene cutting torch (see Figure1-11). Before cutting wire rope, tightly bindthe strands to prevent unlaying. Secure theends that are to be cut by seizing or weldingthem. To use the wire-rope cutter, insertthe wire rope in the bottom of the cutterwith the blade of the cutter coming between

1-14 Rope

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Rope 1-15

the two central seizings. Push the bladedown against the wire rope and strike thetop of the blade sharply with a sledge ham-mer several times. Use the bolt clippers onwire rope of fairly small diameter; however,use an oxyacetylene torch on wire rope ofany diameter. The hacksaw and cold chiselare slower methods of cutting.

DRUMS AND SHEAVES

The size and location of the sheaves anddrums about which wire rope operates andthe speed with which the rope passes overthe sheaves have a definite effect on therope's strength and service life.

Size

Each time wire rope is bent, the individualstrands must move with respect to each

other in addition to bending. Keep thisbending and moving of wires to a minimumto reduce wear. If the sheave or drumdiameter is sufficiently large, the loss ofstrength due to bending wire rope aroundit will be about 5 or 6 percent. In all cases,keep the speed of the rope over the sheavesor drum as slow as is consistent with effi-cient work to decrease wear on the rope. Itis impossible to give an absolute minimumsize for each sheave or drum, since a num-ber of factors enter into this decision. How-ever, Table 1-4, page 1-16, shows theminimum recommended sheave and drumdiameters for several wire-rope sizes. Thesheave diameter always should be as largeas possible and, except for very flexiblerope, never less than 20 times the wire-rope diameter. This figure has beenadopted widely.

Wire ropecutter

Seizings

Blade

Figure 1-11. Wire-rope cutter

1-16 Rope

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Location

You should reeve the drums, sheaves, andblocks used with wire rope and place themin a manner to avoid reverse bends when-ever possible (see Figure 1-12). A reversebend occurs when rope bends in one direc-tion around one block, drum, or sheave andbends in the opposite direction around thenext. This causes the individual wires andstrands to do an unnecessary amount ofshifting, which increases wear. Where youmust use a reverse bend, the block, sheave,or drum causing the reversal should be oflarger diameter than ordinarily used.Space the bend as far apart as possible sothere will be more time allowed betweenthe bending motions.

Winding

Do not overlap wire-rope turns when wind-ing them on the drum of a winch; wrap them

in smooth layers. Overlapping results inbinding, causing snatches on the line whenthe rope is unwound. To produce smooth lay-ers, start the rope against one flange of thedrum and keep tension on the line whilewinding. Start the rope against the right orleft flange as necessary to match the direc-tion of winding, so that when it is rewoundon the drum, the rope will curve in thesame manner as when it left the reel (seeFigure 1-13). A convenient method for deter-mining the proper flange of the drum forstarting the rope is known as the hand rule(see Figure 1-14, page 1-18). The extendedindex finger in this figure points at the on-winding rope. The turns of the rope arewound on the drum close together to preventthe possibility of crushing and abrasion ofthe rope while it is winding and to preventbinding or snatching when it is unwound. Ifnecessary, use a wood stick to force the

Table 1-4. Minimum tread diameter of drums and sheaves

RopeDiameter(inches)

Minimum Tread Diameter for Given RopeConstruction* (inches)

6 x 7 6 x 19 6 x 37 8 x 19

1/4 10 1/2 8 1/2 6 1/2

3/8 15 3/4 12 3/4 6 3/4 9 3/4

1/2 21 17 9 13

5/8 26 1/4 21 1/4 11 1/4 16 1/4

3/4 31 1/2 25 1/2 13 1/2 19 1/2

7/8 36 3/4 29 3/4 15 3/4 22 3/4

1 42 34 18 26

1 1/8 47 1/4 38 1/4 20 1/4 29 1/4

1 1/4 52 1/2 42 1/2 22 1/2 32 1/2

1 1/2 63 51 27 39

*Rope construction is strands and wires per strand.

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Rope 1-17

1 2

3 4

INCORRECT

CORRECT

Drum Drum

DrumDrum

Block

Block

Block

Block

Figure 1-12. Avoiding reverse bends in wire rope

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Drum

Drum

Reel

Reel

Figure 1-13. Spooling wire rope from reel to drum

1-18 Rope

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turns closer together. Striking the wire witha hammer or other metal object damagesthe individual wires in the rope. If possi-ble,wind only a single layer of wirerope on the drum. Where it is necessary towind additional layers, wind them so asto eliminate the binding. Wind the secondlayer of turns over the first layer by placingthe wire in the grooves formed by the first

layer; however, cross each turn of the ropein the second layer over two turns of thefirst layer (see Figure 1-15). Wind the thirdlayer in the grooves of the second layer;however, each turn of the rope will crossover two turns of the second layer.

For overwind on drum—• The palm is down,

facing the drum.• The index finger points

at on-winding rope.• The index finger must

be closest to theleft-side flange.

• The wind of the ropemust be from left toright along the drum.

For underwind on drum—• The palm is up, facing

the drum.• The index finger points


be closest to theright-side flange.

• The wind of the ropemust be from right toleft along the drum.

For overwind on drum—• The palm is down,

facing the drum.• The index finger points


be closest to theright-side flange.

• The wind of the ropemust be from right toleft along the drum.

For underwind on drum—• The palm is up, facing

the drum.• The index finger points


be closest to theleft-side flange.

• The wind of the ropemust be from left toright along the drum.

For right-lay rope(use right hand)

For left-lay rope(use left hand)

If a smooth-face drum has been cut or scored by an old rope,the methods shown may not apply.

Figure 1-14. Determining starting flange of wire rope

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Rope 1-19

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Cross-over tosecond groove

Cross-over two turnsof the second layer

Turn back and firstcross-over forsecond layer

Five turns onsecond layer

Starting third layer

Figure 1-15. Winding wire-rope layers on a drum

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1-20 Rope

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INSPECTION OF WIRE ROPE

Inspect wire rope frequently. Replacefrayed, kinked, worn, or corroded rope. Thefrequency of inspection is determined bythe amount of use. A rope that is used 1 or2 hours a week requires less frequent inspec-tion than one that is used 24 hours a day.

PROCEDURES

Carefully inspect the weak points in ropeand the points where the greatest stressoccurs. Worn spots will show up as shinyflattened spots on the wires.

Inspect broken wires to determine whetherit is a single broken wire or several wires.Rope is unsafe if—

• Individual wires are broken next toone another, causing unequal load dis-tribution at this point.

• Replace the wire rope when 2.5 per-cent of the total rope wires are brokenin the length of one lay, which is thelength along the rope that a strandmakes one complete spiral around therope core. See Figure 1-16.

Figure 1-16. Lay length

One lay

• Replace the wire rope when 1.25 per-cent of the total rope wires are brokenin one strand in one lay.

• Replace wire rope with 200 or morewires (6 x 37 class) when the surfacewires show flat wear spots equal inwidth to 80 percent of the diameter ofthe wires. On wire rope with largerand fewer total wires (6 x 7, 7 x 7, 7 x19), replace it when the flat wear spotwidth is 50 percent of the wire diame-ter.

• Replace the wire if it is kinked or ifthere is evidence of a popped core orbroken wire strands protruding fromthe core strand. See Figure 1-17.

• Replace the wire rope if there is evi-dence of an electrical arc strike (orother thermal damage) or crushingdamage.

• Replace the wire rope if there is evi-dence of "birdcage" damage due toshock unloading. See Figure 1-17.

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Rope 1-21

Figure 1-17. Unserviceable wire rope

Popped core

Birdcage

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CAUSES OF FAILURE

Wire rope failure is commonly caused by—

• Sizing, constructing, or grading itincorrectly.

• Allowing it to drag over obstacles.

• Lubricating it improperly.

• Operating it over drums and sheavesof inadequate size.

• Overwinding or crosswinding it ondrums.

• Operating it over drums and sheavesthat are out of alignment.

• Permitting it to jump sheaves.

• Subjecting it to moisture or acidfumes.

• Permitting it to untwist.

• Kinking.

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C H A P T E R 2

K n o t s , S p l i c e s , A t t a c h m e n t s , a n d

L a d d e r s

Section I. Knots, Hitches, and LashingsA study of the terminology pictured in Figure will aid in understanding the methods of2-1 and the definitions in Table 2-1, page 2-2, knotting presented in this section.

Knots, Splices, Attachments, and Ladders 2-1

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The raw, cut end of a rope has a tendency to the size of the rope. The whipped end of auntwist and should always be knotted or fas- rope will still thread through blocks ortened in some manner to prevent this other openings. Before cutting a rope, placeuntwisting. Whipping is one method of fas- two whippings on the rope 1 or 2 inchestening the end of the rope to prevent apart and make the cut between the whip-untwisting (see Figure 2-2). A rope is pings (see Figure 2-2). This will prevent thewhipped by wrapping the end tightly with a cut ends from untwisting immediatelysmall cord. This method is particularly satis- after they are cut.factory because there is very little increase in

KNOTSA knot is an interlacement of the parts used as a stopper to prevent a rope fromof one or more flexible bodies, such as cord- passing through an opening.age rope, forming a lump. It is also any tie or A good knot must be easy to tie, must holdfastening formed with a rope, including without slipping, and must be easy tobends, hitches, and splices. A knot is often untie. The choice of the best knot, bend, or

2-2 Knots, Splices, Attachments, and Ladders

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hitch to use depends largely on the job ithas to do. In general, knots can be classi-fied into three groups. They are—

Knots at the end of a rope.

Knots for joining two ropes.

Knots for making loops.

KNOTS AT THE END OF ROPEKnots at the end of a rope fall into the fol-lowing categories:

Overhand knot.Figure-eight knot.

Wall knot.

Overhand KnotThe overhand knot is the most commonlyused and the simplest of all knots (see Fig-ure 2-3). Use an overhand knot to prevent

the end of a rope from untwisting, to form aknob at the end of a rope, or to serve as apart of another knot. When tied at the endor standing part of a rope, this knot preventsit from sliding through a block, hole, oranother knot. Use it also to increase a per-son’s grip on a rope. This knot reduces thestrength of a straight rope by 55 percent.

Figure-Eight Knot

Use the figure-eight knot to form a largerknot at the end of a rope than would beformed by an overhand knot (see Figure2-4). The knot prevents the end of the ropefrom slipping through a fastening or loop inanother rope or from unreeving when reevedthrough blocks. It is easy to untie.

Wall Knot

Use the wall knot with crown to preventthe end of a rope from untwisting when an


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enlarged end is not objectionable (see Figure KNOTS FOR JOINING TWO ROPES2-5). The wall knot also makes a desirableknot to prevent the end of the rope from slip-ping through small openings, as when usingrope handles on boxes. Use either the crownor the wall knot separately to form semiper-manent "stopper knots" tied with the endstrands of a rope. The wall knot will preventthe rope from untwisting, but to make aneat round knob, crown it (see Figure 2-6,page 2-6). Notice that in the wall knot, theends come up through the bights, causingthe strands to lead forward. In a crownknot, the ends go down through the bightsand point backward.

Square knot.

Single sheet bend.

Double sheet bend.

Carrick bend.

Square Knot

Knots for joining two ropes fall into the fol-lowing categories:

Use the square knot to tie two ropes ofequal size together so they will not slip (see


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Figure 2-7). Note that in the square knot,the end and standing part of one rope comeout on the same side of the bight formed bythe other rope. The square knot will nothold if the ropes are wet or if they are of dif-ferent sizes. It tightens under strain butcan be untied by grasping the ends of thetwo bights and pulling the knot apart.

NOTE. It makes no differencewhether the first crossing is tiedleft-over-right or right-over-left aslong as the second crossing is tiedopposite to the first crossing.

Single Sheet BendA single sheet bend, sometimes called aweaver’s knot, has two major uses (see Fig-ure 2-8). They are—

Tying together two ropes of unequalsize.

Tying a rope to an eye.This knot will draw tight but will loosen orslip when the lines are slackened. The sin-gle sheet bend is stronger and unties easierthan the square knot.

Double Sheet BendThe double sheet bend has greater holdingpower than the single sheet bend for joiningropes of equal or unequal diameter, joiningwet ropes, or tying a rope to an eye (see Fig-ure 2-9, page 2-8,). It will not slip or drawtight under heavy loads. This knot is moresecure than the single sheet bend when usedin a spliced eye.

Carrick BendUse the carrick bend for heavy loads and forjoining large hawsers or heavy rope (see Fig-ure 2-10, page 2-8). It will not draw tightunder a heavy load and can be untied easilyif the ends are seized to their own standingpart.

KNOTS FOR MAKING LOOPS

Knots for making loops fall into the follow-ing categories:

Bowline.

Double bowline.

Running bowline.


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The

Bowline on a bight.

Spanish bowline.

French bowline.

Speir knot.

Cat’s-paw.

Figure eight with an extra turn.

Bowlinebowline is one of the most common

knots and has a variety of uses, one of whichis the lowering of men and material (see Fig-ure 2-11). It is the best knot for forming asingle loop that will not tighten or slip understrain and can be untied easily if each run-ning end is seized to its own standing part.The bowline forms a loop that may be of anylength.

Double BowlineThe double bowline forms three nonslippingloops (see Figure 2-12, page 2-10). Use thisknot to sling a man. As he sits in the slings,one loop supports his back and the remain-

ing two loops support his legs. A notchedboard that passes through the two loopsmakes a comfortable seat known as a boat-swain’s chair. This chair is discussed in thescaffolding section of this manual (see Chap-ter 6).

Running BowlineThe running bowline forms a strong runningloop (see Figure 2-13, page 2-10). It is a con-venient form of running an eye. The run-ning bowline provides a sling of the chokertype at the end of a single line. Use it whentying a handline around an object at a pointthat you cannot safely reach, such as the endof a limb.

Bowline on a BightThis knot forms two nonslipping loops (seeFigure 2-14, page 2-11). You can use thebowline on a bight for the same purpose as aboatswain’s chair. It does not leave bothhands free, but its twin nonslipping loopsform a comfortable seat. Use it when—

You need more strength than a singlebowline will give.


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Spanish bowline in rescue work or to give aYou need to form a loop at some pointin a rope other than at the end.

You do not have access to the end of arope.

You can easily untie the bowline on a bightand tie it at the end of a rope by doublingthe rope for a short section.

Spanish BowlineYou can tie a Spanish bowline at any point

in a rope, either at a place where the line isdouble or at an end that has been doubledback (see Figure 2-15, page 2-12). Use the

twofold grip for lifting a pipe or other roundobjects in a sling.

French BowlineYou can use the French bowline as a sling tolift injured men (see Figure 2-16, page 2-12).When used for this purpose, one loop is aseat and the other loop is put around thebody under the arms. The injured man’sweight keeps the two loops tight so that hecannot fall out. It is particularly useful as asling for an unconscious man. Also, use theFrench bowline when working alone and you


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need your hands free. The two loops of this a one-rope bridge across a small stream.knot can be adjusted to the size required. You can tie and untie it easily.

Speir Knot KNOTS FOR TIGHTENING A ROPEUse a speir knot when you need a fixed loop, The types of knots used for tightening a ropea nonslip knot, and a quick release (see Fig- are the butterfly knot and the baker bow-ure 2-17). You can tie this knot quickly and line.release it by pulling on the running end.

Cat’s-pawUse a cat’s-paw to fasten an endless sling toa hook, or make it at the end of a rope to fas-ten the rope to a hook (see Figure 2-18). Youcan tie or untie it easily. This knot, which isreally a form of a hitch, is a more satisfactoryway of attaching a rope to a hook than theblackwall hitch. It will not slip off and neednot be kept taut to make it hold.

Butterfly KnotUse the butterfly knot is to pull taut a highline, handline, tread rope for foot bridges, orsimilar installations (see Figure 2-20, page2-14). Using this knot provides the capabil-ity to tighten a fixed rope when mechanicalmeans are not available. (You can also usethe harness hitch for this purpose [see Fig-ure 2-32, page 2-22]). The butterfly knot willnot jam if a stick is placed between the twoupper loops.

Figure Eight With an Extra TurnUse a figure eight with an extra turn to Baker Bowlinetighten a rope (see Figure 2-19, page 2-14). You can use the baker bowline for the sameThis knot is especially suitable for tightening purpose as the butterfly knot and for lashing

cargo (see Figure 2-21, pages 2-15 and 2-16).


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When used to lash cargo, secure one endwith two half hitches, pass the rope over thecargo and tie a baker bowline, then securethe lashing with a slippery half hitch. Torelease the rope, simply pull on the runningend. Advantages of the baker bowline arethat it can be—

Tied easily.

Adjusted without losing control.

Released quickly.

KNOTS FOR WIRE ROPEUnder special circumstances, when wire-rope fittings are not available and it is nec-essary to fasten wire rope by some othermanner, you can use certain knots. In allknots made with wire rope, fasten therunning end of the rope to the standingpart after tying the knot. When wire-ropeclips are available, use them to fasten therunning end. If clips are not available, use


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wire or strands of cordage. Check all knots sive wear, cut off a short length of the endin wire rope periodically for wear or signs of of the rope, including the knot, and tie abreakage. If there is any reason to believe new knot. Use the fisherman’s bend, clovethat the knot has been subjected to exces- hitch, and carrick bend to fasten wire rope.

HITCHES

A hitch is any of various knots used to forma temporary noose in a rope or to secure arope around a timber, pipe, or post so thatit will hold temporarily but can be readilyundone. The types of hitches are as follows:

Half hitch.Two half hitches.Round turn and two half hitches.Timber hitch.Timber hitch and half hitch.Clove hitch.Rolling hitch.Telegraph hitch.Mooring hitch.Scaffold hitch.Blackwall hitch.Harness hitch.Girth hitch.

Sheepshank.Fisherman’s bend.

HALF HITCHUse the half hitch to tie a rope to a timberor to a larger rope (see Figure 2-22, A). Itwill hold against a steady pull on thestanding part of the rope; however, it is nota secure hitch. You can use the half hitchto secure the free end of a rope and as anaid to and the foundation of many knots.For example, it is the start of a timberhitch and a part of the fisherman’s knot. Italso makes the rolling hitch more secure.

TWO HALF HITCHESTwo half hitches are especially useful forsecuring the running end of a rope to thestanding part (see Figure 2-22, B). If thetwo hitches are slid together along thestanding part to form a single knot, theknot becomes a clove hitch.


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ROUND TURN AND TWO HALF HITCHES

Another hitch used to fasten a rope to apole, timber, or spar is the round turn andtwo half hitches (see Figure 2-23). Forgreater security, seize the running end ofthe rope to the standing part. This hitchdoes not jam.

TIMBER HITCH

Use the timber hitch to move heavy timberor poles (see Figure 2-24). It is excellent forsecuring a piece of lumber or similarobjects. The pressure of the coils, one overthe other, holds the timber securely; themore tension applied, the tighter the hitchbecomes about the timber. It will not slipbut will readily loosen when the strain isrelieved.

TIMBER HITCH AND HALF HITCHA timber hitch and half hitch are combinedto hold heavy timber or poles when they arebeing lifted or dragged (see Figure 2-25). Atimber hitch used alone may become untiedwhen the rope is slack or when a suddenstrain is put on it.

CLOVE HITCHThe clove hitch is one of the most widelyused knots (see Figure 2-26, page 2-19). Youcan use it to fasten a rope to a timber, pipe,or post. You can also use it to make otherknots. This knot puts very little strain onthe fibers when the rope is put around anobject in one continuous direction. You cantie a clove hitch at any point in a rope. Ifthere is not constant tension on the rope,another loop (round of the rope around theobject and under the center of the clovehitch) will permit a tightening and slacken-ing motion of the rope.

ROLLING HITCHUse the rolling hitch to secure a rope toanother rope or to fasten it to a pole or pipe


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so that the rope will not slip (see Figure This hitch grips tightly and is easily2-27, page 2-20). This knot grips tightly butis easily moved along a rope or pole whenthe strain is relieved.

TELEGRAPH HITCHThe telegraph hitch is a very useful andsecure hitch that you can use to hoist or haulposts and poles (see Figure 2-28, page 2-20).It is easy to tie and untie and will not slip.

MOORING HITCHUse the mooring hitch, also called rolling ormagnus hitch, to fasten a rope around amooring post or to attach a rope at a rightangle to a post (see Figure 2-29, page 2-21).

removed.

SCAFFOLD HITCHUse the scaffold hitch to support the end of ascaffold plank with a single rope (see Figure2-30, page 2-21). It prevents the plank fromtilting.

BLACKWALL HITCHUse the blackwall hitch to fasten a rope to ahook (see Figure 2-31, page 2-22). Gener-ally, use it to attach a rope, temporarily, to ahook or similar object in derrick work. Thehitch holds only when subjected to a con-stant strain or when used in the middle of a


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rope with both ends secured. Human lifeand breakable equipment should never beentrusted to the blackwall hitch.

HARNESS HITCHThe harness hitch forms a nonslipping loopin a rope (see Figure 2-32). It is oftenemployed by putting an arm through theloop, then placing the loop on the shoulder

The hitch is tied only in the middle of a rope.It will slip if only one end of the rope ispulled.

GIRTH HITCHUse the girth hitch to tie suspender ropes tohand ropes when constructing expedient footbridges (see Figure 2-33). It is a simple andconvenient hitch for many other uses of

and pulling the object attached to the rope. ropes and cords.


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SHEEPSHANKA sheepshank is a method of shortening arope, but you can use it to take the load off aweak spot in the rope (see Figure 2-34). It isonly a temporary knot unless the eyes arefastened to the standing part on each end.

FISHERMAN’S BENDThe fisherman’s bend is an excellent knot forattaching a rope to a light anchor, a ring,or a rectangular piece of stone (see Figure 2-35, page 2-24). You can use it to fasten arope or cable to a ring or post. Also use itwhere there will be a slackening and tight-ening motion in the rope.


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LASHINGS

A lashing is as rope, wire, or chain used forbinding, wrapping, or fastening. The typesof lashings include square, shears, andblock.

SQUARE LASHINGUse the square lashing to lash two sparstogether at right angles to each other (seeFigure 2-36). To tie a square lashing, beginwith a clove hitch on one spar and make aminimum of four complete turns aroundboth members. Continue with two frappingturns between the vertical and the horizon-tal spar to tighten the lashing. Tie off therunning end to the opposite spar fromwhich you started with another clove hitchto finish the square lashing.

SHEARS LASHING

Use the shears lashing to lash two sparstogether at one end to form an expedientdevice called a shears (see Figure 2-37). Dothis by laying two spars side by side,spaced about one-third of the diameter of aspar apart, with the butt ends together.Start the shears lashing a short distance infrom the top of one of the spars by tying theend of the rope to it with a clove hitch.Then make eight tight turns around bothspars above the clove hitch. Tighten thelashing with a minimum of two frappingturns around the eight turns. Finish theshears lashing by tying the end of the ropeto the opposite spar from which you startedwith another clove hitch.


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BLOCK LASHINGUse the block lashing to tie a tackle block toa spar (see Figure 2-38). First, make threeright turns of the rope around the sparwhere the tackle block is to be attached.Pass the next two turns of the rope throughthe mouth of the hook or shackle of thetackle block and drawn tightly. Then putthree additional taut turns of the ropearound the spar above the hook or shackle.Complete the block lashing by tying the twoends of the rope together with a squareknot. When a sling is supported by a blocklashing, pass the sling through the centerfour turns.

Section II.Splicing is a method of joining fiber or wirerope by unlaying strands of both ends andinterweaving these strands together. Thegeneral types of splices are—

A short splice.An eye or side splice.A long splice.

A crown or back splice.

SplicesThe methods of making all four types ofsplices are similar. They generally consistof the following basic steps—

Unlaying the strands of the rope.

Placing the rope ends together.

Interweaving the strands and tuckingthem into the rope.

FIBER-ROPE SPLICES

When one strand of a rope is broken, youcannot repair it by tying the ends togetherbecause this would shorten the strand.Repair it by inserting a strand longer thanthe break and tying the ends together (seeFigure 2-39).

SHORT SPLICEThe short splice is as strong as the rope inwhich it is made and will hold as much as along splice (see Figure 2-40). However, theshort splice causes an increase in the diame-ter of the rope for a short distance and canbe used only where this increase in diameterwill not affect operations. It is called the

short splice because a minimum reductionin rope length takes place in making thesplice. This splice is frequently used torepair damaged ropes when two ropes of thesame size are to be joined together perma-nently. Cut out the damaged parts of therope and splice the sound sections.

EYE OR SIDE SPLICEUse the eye or side splice to make a perma-nent loop in the end of a rope (see Figure2-41, page 2-28). You can use the loops,made with or without a thimble, to fastenthe rope to a ring or hook. Use a thimbleto reduce wear. Use this splice also to splice


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one rope into the side of another. As a per- The ropes to be joined should be the samemanent loop or eye, no knot can comparewith this splice for neatness and efficiency.

LONG SPLICEUse the long splice when the larger diameterof the short splice has an adverse effect onthe use of the rope; use it also to splice longropes that operate under heavy stress (seeFigure 2-42). This splice is as strong as therope itself. A skillfully made long splice willrun through sheaves without any difficulty.

lay and as nearly the same diameter aspossible.

CROWN OR BACK SPLICEWhen you are splicing the end of a rope toprevent unlaying, and a slight enlarge-ment of the end is not objectionable, use acrown splice to do this (see Figure 2-43,page 2-30). Do not put any length of ropeinto service without properly preparing theends.


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WIRE-ROPE SPLICESIn splicing wire rope, it is extremely impor-tant to use great care in laying the variousrope strands firmly into position. Slackstrands will not receive their full share of theload, which causes excessive stress to be puton the other strands. The unequal stressdistribution will decrease the possible ulti-mate strength of the splice. When usingsplices in places where their failure mayresult in material damage or may endangerhuman lives, test the splices under stressesequal to at least twice their maximum work-ing load before placing the ropes into service.Table 2-2 shows the amount or length of ropeto be unlaid on each of the two ends of theropes and the amount of tuck for ropes of dif-ferent diameters. As a rule of thumb, usethe following:

Long splice, 40 times the diameter.

Short splice, 20 times the diameter.You need only a few tools to splice wire rope.In addition to the tools shown in Figure 2-44,page 2-32, a hammer and cold chisel areoften used to cut the ends of strands. Usetwo slings of marline and two sticks to

untwist the wire. A pocket knife may beneeded to cut the hemp core.

SHORT SPLICEA short splice develops only from 70 to 90percent of the strength of the rope. Since ashort splice is bulky, it is used only for blockstraps, slings, or where an enlargement ofthe diameter is of no importance. It is notsuitable for splicing driving ropes or ropesused in running tackles and should neverbe put into a crane or hoist rope. The wirerope splice differs from the fiber ropeshort splice only in the method by which theend strands are tucked (see Figure 2-45,page 2-32).

EYE OR SIDE SPLICEAn eye splice can be made with or without athimble. Use a thimble for every rope eyeunless special circumstances prohibit it (seeFigure 2-46, page 2-33). The thimble pro-tects the rope from sharp bends and abra-sive action. The efficiency of a well-madeeye splice with a heavy-duty thimble varies


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from 70 to 90 percent. Occasionally, it be-comes necessary to construct a field expedi-ent, called a hasty eye (see Figure 2-47).The hasty eye can be easily and quicklymade but is limited to about 70 percent ofthe strength of the rope; consequently, itshould not be used to hoist loads.

LONG SPLICE

Use the long splice to join two ropes or tomake an endless sling without increasingthe thickness of the wire rope at the splice(see Figure 2-48, page 2-34). It is the bestand most important kind of splice because itis strong and trim.

Round-Strand, Regular-Lay RopeThe directions given in Figure 2-48 are formaking a 30-foot splice in a three-fourths


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inch regular-lay, round-strand, hemp-center because of the tendency of the rope towire rope. Other strand combinations differ untwist. Up to the point of tucking theonly when there is an uneven number of ends, follow the procedure for regular lay.strands. In splicing ropes having an odd Then, instead of laying the strands side bynumber of strands, make the odd tuck at the side where they pass each other, crosscenter of the splice. them over to increase the holding power of

the splice. At the point where they cross,Round-Strand, Lang-Lay Rope untwist the strands for a length of about 3

In splicing a round-strand, Lang-lay rope, itinches so they cross over each other with-out materially increasing the diameter of

is advisable to make a slightly longer splice the rope. Then finish the tucks in thethan for the same size rope of regular lay usual manner.

Section III. AttachmentsMost of the attachments used with wire rope a number of attachments used with the eyeare designed to provide an eye on the end of splice. Any two of the ends can be joinedthe rope by which maximum strength can be together, either directly or with the aid of aobtained when the rope is connected with shackle or end fitting. These attachmentsanother rope, hook, or ring. Figure 2-49 shows for wire rope take the place of knots.


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END FITTINGS

An end fitting may be placed directly on wire age to another wire rope. Table 2-3, page 2-rope. Fittings that are easily and quicklychanged are clips, clamps, and wedge sockets.

CLIPSWire-rope clips are reliable and durable (seeFigure 2-50, page 2-36). Use them, repeat-edly, to make eyes in wire rope, either for asimple eye or an eye reinforced with a thim-ble, or to secure a wire-rope line or anchor-

36 shows the number-and spacing of clipsand the proper torque to apply to the nuts ofthe clips. After installing all the clips,tighten the clip farthest from the eye (thim-ble) with a torque wrench. Next, place therope under tension and tighten the clip nextto the clip you tightened first. Tighten theremaining clips in order, moving toward theloop (thimble). After placing the rope inservice, tighten the clips again immediately


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after applying the working load and at fre-quent intervals thereafter. Retightening isnecessary to compensate for the decrease inrope diameter that occurs when the strandsadjust to the lengthwise strain caused by theload. Position the clips so that they areimmediately accessible for inspection andmaintenance.

CLAMPS

A wire clamp can be used with or without athimble to make an eye in wire rope (see Fig-ure 2-51). Ordinarily, use a clamp to makean eye without a thimble. It has about 90percent of the strength of the rope. Tightenthe two end collars with wrenches to forcethe clamp to a good snug fit. This crushesthe pieces of rope firmly against each other.

WEDGE SOCKETUse a wedge-socket end fitting when it isnecessary to change the fitting at frequentintervals (see Figure 2-52, page 2-38). Theefficiency is about two-thirds of the strengthof the rope. It is made in two parts. Thesocket itself has a tapered opening for thewire rope and a small wedge to go into this

tapered socket. The loop of wire rope mustbe inserted in the wedge socket so that thestanding part of the wire rope will form anearly direct line to the clevis pin of the fit-ting. A properly installed wedge-socket con-nection will tighten when a strain is placedon the wire rope.

BASKET-SOCKET END FITTING

The basket-socket end fittings include closedsockets, open sockets, and bridge sockets(see Figure 2-53, page 2-38). This socket isordinarily attached to the end of the ropewith molten zinc and is a permanent endrifting. If this fitting is properly made up, itis as strong as the rope itself. In all cases,the wire rope should lead from the socket inline with the axis of the socket.

WARNING

Never use babbitt, lead, or dry method toattach a basket socket end fitting.

POURED METHOD

The poured basket socket is the most satis-factory method in use (see Figure 2-54, page2-39). If the socketing is properly done, awire rope, when tested to destruction, willbreak before it will pull out from the socket.

Figure 2-51. Wire-rope clamps

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Deadend

Deadend

Live endLive end

Not

long

enou

gh6to

9tim

esdi

amet

er

Add clamp andshort cablesplice.

WRONG

READY-TO-USE

Enteringwrong side

RIGHT

CAUTION

Never clamp the live end to the deadend. Add the clamp and the short cablesplice to the dead end as shown above.

Figure 2-52. Wedge socket

Closedsocket

Opensocket

Bridgesocket

Wedgesocket

Figure 2-53. Basket-socket end fittings

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Spread the wires ineach strand.

Unlay the strands equalto the length of thesocket.

Pull the ropeinto the socket. Place putty or

clay here.

Pour in moltenzinc.

1

2 3

Figure 2-54. Attaching basket sockets by pouring

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DRY METHOD

The dry method should be used only whenfacilities are not available for the poured

method (see Figure 2-55). The strength ofthe connection must be assumed to bereduced to about one-sixth of the strengthof a poured zinc connection.

STANCHIONS

The standard pipe stanchion is made up of a1-inch diameter pipe (see Figure 2-56). Eachstanchion is 40 inches long. Two 3/4-inchwire-rope clips are fastened through holes inthe pipe with the centers of the clips 36inches apart. Use this stanchion, without

modifying it, for a suspended walkwaythat uses two wire ropes on each side.However, for handlines, remove or leaveoff the lower wire-rope clip. For more infor-mation on types and uses of stanchions,see TM 5-270.

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Section IV. Rope Ladders

Ropes may be used in the construction of

HANGING

Hanging ladders are made of wire or fiberrope anchored at the top and suspended ver-tically. They are difficult to ascend anddescend, particularly for a man carrying apack or load and should be used only whennecessary. The uprights of hanging laddersmay be made of wire or fiber rope andanchored at the top and bottom.

hanging ladders and standoff ladders.

LADDERS

WIRE-ROPE LADDERS

Wire-rope uprights with pipe rungs makethe most satisfactory hanging ladders be-cause they are more rigid and do not sag asmuch as hanging ladders made of othermaterial. Wire-rope uprights with wire-roperungs are usable.


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Wire-Rope Ladder With Pipe Rungs clips in the stanchion over 3/4-inch wire-ropeMake a wire-rope ladder using either l-inch uprights (see Figure 2-57). If you use 3/8-inchor 3/4-inch pipe rungs. The l-inch pipe wire-rope uprights, insert 3/8-inch wire-roperungs are more satisfactory. For such lad- clips in the pipe over the wire-rope uprights.ders, use the standard pipe stanchion. When you use 3/4-inch pipe rungs, space theSpace the pipe stanchions 12 inches apart in rungs 12 inches apart in the ladder, but dothe ladder and insert the 3/4-inch wire-rope not space the uprights more than 12 inches


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apart because of using weaker pipe. Therungs may be fastened in place by two differ-ent methods. In one method, drill a 7/16-inch diameter hole at each end of each piperung and thread 3/8-inch wire-rope uprightsthrough the holes. To hold each rung inplace, fasten a 3/8-inch wire-rope clip aboutthe wire-rope upright at each end of eachrung after the rung is in its final position. Inthe other method, cut the pipe rungs 12inches long and weld the U-bolt of a 3/8-inchrope clip to each end. Space the rungs 12inches apart on the 3/8-inch wire-ropeuprights. Place the saddle of the wire-ropeclips and the nuts on the U-bolts; tighten thenuts to hold the rungs in place.

Wire-Rope Ladder With Wire-Rope RungsMake a wire-rope ladder with wire-roperungs by laying the 3/8-inch diameter wire-

first length in a series of U-shaped bends.Lay out the second length in a similar man-ner with the U-shaped bends in the oppositedirection from those in the first series andthe horizontal rung portions overlapping(see Figure 2-58). Fasten a 3/8-inch wire-rope clip on the overlapping rung portions ateach end of each rung to hold them firm.

FIBER-ROPE LADDERS

Fiber-rope uprights with wood or fiber-roperungs are difficult to use because theirgreater flexibility causes them to twist whenthey are being used. Place a log at the breakof the ladder at the top to hold the uprightsand rungs away from a rock face to providebetter handholds and footholds. A singlerock anchor at the bottom of the ladder isusually sufficient. You can also use a pile ofrocks as the bottom anchor for fiber-rope

rope uprights on the ground. Lay out the hanging ladders.


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Fiber-Rope Ladder With Fiber-Rope RungsMake fiber-rope ladders with fiber-roperungs by using two or three uprights. Whenyou use three uprights, make a loop in thecenter upright at the position of each rung(see Figure 2-59). Space the two outsideuprights 20 inches apart. A loop and a singlesplice hold each end of each rung to the out-side upright. A loop in the center of the rungpasses through the loop in the centerupright. If you use only two uprights, holdthe rungs in place by a loop and a rollinghitch or a single splice at each upright. Thetwo uprights must be closer together, withshorter rungs, to stiffen the ladder. Laddersof either type are very flexible and difficultto climb.

Fiber-Rope Ladder With Wood RungsMake fiber-rope ladders with wood rungs by

rungs (see Figure 2-60). When you usenative material, cut the rungs from 2-inch-diameter material about 15 inches long.Notch the ends of each rung and fasten therung to the fiber-rope upright with a clovehitch. Space the rungs 12 inches apart.Twist a piece of seizing wire about the backof the clove hitch to make it more secure andin a manner that will not snag the clothingof persons climbing the ladder. If you makethe rungs of finished lumber, cut them tosize and drill a 3/4-inch hole at each end.Oak lumber is best for this purpose. Put al/4-inch by 2-inch carriage bolt horizontallythrough each end near the vertical hole toprevent splitting. Tie an overhand knot inthe upright to support the rung. Thenthread the upright through the 3/4-inch holein the rung. Tie a second overhand knot inthe upright before you thread it through thenext rung. Continue this Procedure until

using finished lumber or native material for you reach-the desired length of the ladder.


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STANDOFF LADDERSStandoff ladders are easier to climb than transported easily. One or two standoff lad-hanging ladders because they have two ders are adequate for most purposes, butwood or metal uprights that hold them three or four hanging ladders must be pro-rigid, and they are placed at an angle. Both vialed for the same purpose because they aretypes of ladders can be prefabricated and more difficult to use.


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C H A P T E R 3

H o i s t s

Section I. Chains and Hooks

Chains are much more resistant to abrasion In lifting, chains, as well as fiber ropesand corrosion than wire rope; use them or wire ropes, can be tied to the load. Butwhere this type of deterioration is a problem, for speed and convenience, it is muchas in marine work where anchor gear must better to fasten a hook to the end of thewithstand the corrosive effects of seawater. lifting line. Also, you can use hooks areYou can also use chains to lift heavy objects in constructing blocks.with sharp edges that would cut wire.

CHAINS

Chains are made up of a series of links fas-tened through each other. Each link ismade of a rod of wire bent into an ovalshape and welded at one or two points. Theweld ordinarily causes a slight bulge on theside or end of the link (see Figure 3-1). Thechain size refers to the diameter, in inches,of the rod used to make the link. Chainsusually stretch under excessive loading sothat the individual links bend slightly.Bent links are a warning that the chain hasbeen overloaded and might fail suddenlyunder a load. Wire rope, on the other hand,fails a strand at a time, giving warningbefore complete failure occurs. If a chain isequipped with the proper hook, the hookshould start to fail first, indicating that thechain is overloaded.Several grades and types of chains areavailable.

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STRENGTH OF CHAINSTo determine the SWC on a chain, apply aFS to the breaking strength. The SWC ordi-narily is assumed to be about one-sixth ofthe BS, giving a FS of 6. Table 3-1 lists SWCfor various chains. You can approximate theSWC of an open-link chain by using the fol-lowing rule of thumb:

SWC = 8D2

SWC = Safe working capacity, in tonsD = Smallest link thickness or least diam-eter measured in inches (see Figure 3-1,page 3-1)

Example: Using the rule of thumb, the SWC

of a chain with a link thickness of 3/4 inchis—

SWC = 8D2 = 8 (3/4)2 = 4.5 tons or9,000 pounds

The figures given assume that the load isapplied in a straight pull rather than by animpact. An impact load occurs when anobject is dropped suddenly for a distanceand stopped. The impact load in such acase is several times the weight of the load.

CARE OF CHAINSWhen hoisting heavy metal objects usingchains for slings, insert padding aroundthe sharp corners of the load to protect the

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chain links from being cut. The padding Cut the smaller chain links with a boltmay be either planks or heavy fabric. Do cutter; cut large chain links with a hack-not permit chains to twist or kink when saw or an oxyacetylene torch. Inspect theunder strain. Never fasten chain links chain chains frequently, depending on thetogether with bolts or wire because such amount of use. Do not paint chains toconnections weaken the chain and limit prevent rusting because the paint willits SWC. Cut worn or damaged links out interfere with the action of the links.of the chain and replace them with a cold- Instead, apply a light coat of lubricant andshut link. Close the cold-shut link and weld store them in a dry and well-ventilatedit to equal the strength of the other links. place.

HOOKS

The two general types of hooks availableare the slip hook and the grab hook (seeFigure 3-2). Slip hooks are made so thatthe inside curve of the hook is an arc of acircle and may be used with wire rope.chains. or fiber rope. Chain links can slipthrough a slip hook so the loop formed inthe chain will tighten under a load. Grabhooks have an inside curve that is nearlyU-shaped so that the hook will slip over alink of chain edgeways but will not permitthe next link to slip through. Grab hookshave a more limited range of use than sliphooks. They are used on chains when theloop formed with the hook is not intended toclose up around the load.

STRENGTH OF HOOKSHooks usually fail by straightening. Anydeviation from the original inner arc indi-cates that the hook has been overloaded.Since you can easily detect evidence ofoverloading the hook. you should use ahook that is weaker than the chain towhich it is attached. With this system.hook distortion will occur before the chainis overloaded. Discard severely distorted.cracked. or badly worn hooks because theyare dangerous. Table 3-2. page 3-4. listsSWCs on hooks. Approximate the SWC ofa hook by using the following rule ofthumb:

SWC = D2

D = the diameter in inches of the hookwhere the inside of the hook starts itsarc (see Figure 3-3. page 3-5)

Thus. the SWC of a hook with a diameterof 1 1/4 inches is as follows:

SWC=D2=(1 1/4)2 16 tons or 3,125pounds

MOUSING OF HOOKSIn general. always “mouse” a hook as asafety measure to prevent slings or ropesfrom jumping off. To mouse a hook afterthe sling is on the hook. wrap the wire orheavy twine 8 or 10 turns around the twosides of the hook (see Figure 3-4. page 3-5).

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Complete the process by winding several securely. Mousing also helps preventturns of the wire or twine around the straightening of the hook but does notsides of the mousing and tying the ends strengthen it materially.

INSPECTING CHAINS AND HOOKS

Inspect chains, including the hooks, at least and cracks, sharp nicks or cuts, worn sur-once a month; inspect those that are used faces, and distortions. Replace those thatfor heavy and continuous loading more fre- show any of these weaknesses. If severalquently. Give particular attention to the links are stretched or distorted, do not usesmall radius fillets at the neck of hooks for the chain; it probably was overloaded orany deviation from the original inner arc. hooked improperly, which weakened theExamine each link and hook for small dents entire chain.

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Section II. SlingsThe term “sling” includes a wide variety ofdesigns. Slings may be made of fiber rope,wire rope, or chain.Fiber rope makes good slings because of itsflexibility, but it is more easily damaged bysharp edges on the material hoisted than arewire rope or chain slings. Fiber-rope slingsare used for lifting comparatively light loadsand for temporary jobs.Wire rope is widely used for slings because ithas a combination of strength and flexibility.Properly designed and appropriately fabri-cated wire-rope slings are the safest type ofslings. They do not wear away as do slings

made of fiber rope, nor do they lose theirstrength from exposure as rapidly. Theyalso are not susceptible to the “weakestlink” condition of chains caused by theuncertainty of the strengths of the welds.The appearance of broken wires clearlyindicates the fatigue of the metal and theend of the usefulness of the sling.Chain slings are used especially wheresharp edges of metal would cut wire rope orwhere very hot items are lifted, as in found-ries or blacksmith shops.Barrel slings can be made with fiber rope tohold barrels horizontally or vertically.

TYPES OF SLINGSThe sling for lifting a given load may be— ENDLESS SLINGS

An endless sling. The endless sling is made by splicing the

A single sling. ends of a piece of wire rope or fiber ropetogether or by inserting a cold-shut link in a

A combination sling (several single chain. Cold-shut links should be weldedslings used together). after insertion in the chain. These endless

Each type or combination has its particular slings are simple to handle and may be usedadvantages that must be considered when in several different ways to lift loads (seeselecting a sling for a given purpose. Figure 3-5, page 3-6).

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Choker or Anchor HitchA common method of using an endless slingis to cast the sling under the load to be liftedand insert one loop through the other andover the hoisting hook. When the hoistinghook is raised, one side of the choker hitch isforced down against the load by the strainon the other side, forming a tight grip on theload.

Basket HitchWith this hitch, the endless sling is passedaround the object to be lifted and bothremaining loops are slipped over the hook.

Inverted Basket HitchThis hitch is very much like the simple bas-ket hitch except that the two parts of the sling going under the load are spread wideapart.

Toggle HitchThe toggle hitch is used only for specialapplications. It is actually a modification of

the inverted basket hitch except that theline passes around toggles fastened to theload rather than going around the loaditself.

SINGLE SLINGSA single sling can be made of wire rope, fiberrope, or chain. Each end of a single sling ismade into an eye or has an attached hook(see Figure 3-6). In some instances, theends of a wire rope are spliced into the eyesthat are around the thimbles, and one eye isfastened to a hook with a shackle. With thistype of single sling, you can remove theshackle and hook when desired. You canuse a single sling in several different waysfor hoisting (see Figure 3-6). It is advisableto have four single slings of wire rope avail-able at all times. These can be used singlyor in combination, as necessary.

Choker or Anchor HitchA choker or anchor hitch is a single slingthat is used for hoisting by passing one eye

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through the other eye and over the hoistinghook. A choker hitch will tighten downagainst the load when a strain is placed onthe sling.

Basket Hitch

A basket hitch is a single sling that ispassed under the load with both endshooked over the hoisting hook.

Stone-Dog HitchA stone-dog hitch is single slings with twohooks that are used for lifting stone.

Double Anchor HitchThis hitch is used for hoisting drums orother cylindrical objects where it is neces-sary for the sling to tighten itself understrain and lift by friction against the sides ofthe cylinder.

COMBINATION SLINGSSingle slings can be combined into bridleslings, basket slings, and choker slings tolift virtually any type of load. Either twoor four single slings can be used in a givencombination. Where greater length isrequired, two of the single slings can be com-bined into a longer single sling. One of theproblems in lifting heavy loads is in fasten-ing the bottom of the sling legs to the load insuch a way that the load will not be dam-aged. Lifting eyes are fastened to manypieces of equipment at the time it is manu-factured. On large crates or boxes, the slinglegs may be passed under the object to forma gasket sling. A hook can be fastened to theeye on one end of each sling leg to permiteasier fastening on some loads. Where theload being lifted is heavy enough or awk-ward enough, a four-leg sling may berequired. If a still greater length of sling isrequired, two additional slings can be usedin conjunction with the four-leg sling to forma double basket.

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PALLETS

A problem in hoisting and moving loads the job out of 2- by 8-inch timbers that are 6sometimes occurs when the items to be or 8 feet long and are nailed to three or fourlifted are packaged in small boxes and the heavy cross members, such as 4- by 8-inchindividual boxes are not crated. In this timbers. Several pallets should be made upcase, it is entirely too slow to pick up each so that one pallet can be loaded while thesmall box and move it separately. Pallets, pallet previously loaded is being hoisted. Asused in combination with slings, provide each pallet is unloaded, the next return tripan efficient method of handling such of the hoist takes the empty pallet back forloads. The pallets can be made up readily on loading.

SPREADERSOccasionally, it is necessary to hoist loads that of the load, the angle of the sling leg isare not protected sufficiently to prevent crush- changed so that crushing of the load is pre-ing by the sling legs. In such cases, spreaders vented. Changing the angle of the sling legmay be used with the slings (see Figure 3-7). may increase the stress in that portion ofSpreaders are short bars or pipes with eyes on the sling leg above the spreaders. The deter-each end. The sling leg passes through the eye mining factor in computing the safe liftingdown to its connection with the load. By set- capacity of the sling is the stress (or tension)ting spreaders in the sling legs above the top in the sling leg above the spreader.

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STRESSESTables 3-3 through 3-5, pages 3-10through 3-12, list the SWCs of ropes,chains, and wire-rope slings under variousconditions. The angle of the legs of a slingmust be considered as well as the strength ofthe material of which a sling is made. Thelifting capacity of a sling is reduced as theangle of its legs to the horizontal is reduced(as the legs of a sling are spread) (see Figure3-7). Thus, reducing the angle of the legs ofa sling increases the tension on the slinglegs. In determining the proper size of sling,you must determine the tension on each legfor each load (see Figure 3-8, page 3-13).You can compute this tension using the fol-lowing formula:

T = Tension in a single sling leg (whichmay be more than the weight of the loadlifted)W= Weight of the load to be liftedN = Number of slingsL = Length of slingV = Vertical distance, measured from thehook to the top of the loadNOTES:

1. L and V must be expressed in thesame unit of measure.2. The resulting tension will be inthe same unit of measure as that ofthe weight of the load. Thus, if theweight of the load is in pounds, thetension will be given in pounds.

Example: Determine the tension of a singleleg of a two-legged sling being used to lift aload weighing 1,800 pounds. The length ofa sling is 8 feet and the vertical distance is 6feet.

Solution:

T=

T= 1,200 pounds or 6 tons

By knowing the amount of tension in a sin-gle leg, you can determine the appropriatesize of fiber rope, wire rope, or chain. TheSWC of a sling leg (keeping within thesafety factors for slings) must be equal to orgreater than the tension on a sling leg. Ifpossible, keep the tension on each sling legbelow that in the hoisting line to which thesling is attached. A particular angle formedby the sling legs with the horizontal wherethe tension within each sling leg equals theweight of the load is called the critical angle(see Figure 3-9, page 3-13). Approximatethis angle using the following formula:

Critical angle =

N = Number of sling legs

When using slings, stay above the criticalangle.

INSPECTING AND CUSHIONING SLINGSInspect slings periodically and condemn 4 percent or more of the wires are broken.them when they are no longer safe. Make Pad all objects to be lifted with wood blocks,the usual deterioration check for fiber ropes, heavy fabric, old rubber tires, or other cush-wire ropes, chains, and hooks when you use ioning material to protect the legs of slingsthem in slings. Besides the usual precautions, from being damaged.declare wire ropes used in slings unsafe if

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Section III. Blocks and Tackle Systems

A force is a push or pull. The push or pullthat humans can exert depends on theirweight and strength. To move any loadheavier than the maximum amount a per-son can move, use a machine that multi-plies the force exerted into a force capable ofmoving the load. The machine may be alever, a screw, or a tackle system. The sameprinciple applies to all of them. If you use amachine that exerts a force 10 times greaterthan the force applied to it, the machine hasmultiplied the force input by 10. Themechanical advantage (MA) of a machine isthe amount by which the machine multi-plies the force applied to it to lift or move aload. For example, if a downward push of 10pounds on the left end of a lever will causethe right end of the lever to raise a loadweighing 100 pounds, the lever is said tohave a MA of 10.

A block consists of a wood or metal framecontaining one or more rotating pulleyscalled sheaves (see Figure 3-10, A). A tackleis an assembly of ropes and blocks used tomultiply forces (see Figure 3-10, B). Thenumber of times the force is multiplied isthe MA of the tackle. To make up a tacklesystem, lay out the blocks you are to use tobe used and reeve (thread) the rope throughthe blocks. Every tackle system contains afixed block attached to some solid supportand may have a traveling block attached tothe load. The single rope leaving the tacklesystem is called the fall line. The pullingforce is applied to the fall line, which maybe led through a leading block. This is anadditional block used to change the direc-tion of pull.

BLOCKSBlocks are used to reverse the direction ofthe rope in the tackle. Blocks take theirnames from—

The purpose for which they are used.

The places they occupy.

A particular shape or type of construc-tion (see Figure 3-11).

TYPES OF BLOCKSBlocks are designated as single, double, ortriple, depending on the number of sheaves.

Snatch BlockThis is a single sheave block made so thatthe shell opens on one side at the base of thehook to permit a rope to be slipped over thesheave without threading the end of itthrough the block. Snatch blocks ordinarily

are used where it is necessary to changethe direction of the pull on the line.

Traveling BlockA traveling block is attached to the loadthat is being lifted and moves as the load islifted.

Standing BlockThis block is fixed to a stationary object.

Leading BlocksBlocks used in the tackle to change thedirection of the pull without affecting theMA of the system are called leading blocks(see Figure 3-12, page 3-16). In some tacklesystems, the fall line leads off the last blockin a direction that makes it difficult toapply the motive force required. A leadingblock is used to correct this. Ordinarily, a

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snatch block is used as the leading block.This block can be placed at any convenientposition. The fall line from the tackle sys-tem is led through the leading block to theline of most direct action. -

REEVING BLOCKSTo prepare blocks for use, reeve, or pass arope through, it. To do this, lay out theblocks on a clean and level surface otherthan the ground to avoid getting dirt intothe operating parts, Figure 3-13 shows thereeving of single and double blocks. In reev-ing triple blocks, it is imperative that youput the hoisting strain at the center of theblocks to prevent them from being inclinedunder the strain (see Figure 3-14). If theblocks do incline, the rope will drag acrossthe edges of the sheaves and the shell of theblock and cut the fibers. Place the blocks sothat the sheaves in one block are at rightangles to the sheaves in the other block.You may lay the coil of rope beside eitherblock. Pass the running end over the centersheave of one block and back to the bottomsheave of the other block. Then pass it overone of the side sheaves of the first block. Inselecting which side sheave to pass the rope

over, remember that the rope should notcross the rope leading away from the cen-ter sheave of the first block. Lead the ropeover the top sheave of the second blockand back to the remaining side sheave ofthe first block. From this point, lead therope to the center sheave of the secondblock and back to the becket of the firstblock. Reeve the rope through the blocksso that no part of the rope chafes anotherpart of the rope.

Twisting of BlocksReeve blocks so as to prevent twisting.After reeving the blocks, pull the rope backand forth through the blocks several timesto allow the rope to adjust to the blocks.This reduces the tendency of the tackle totwist under a load. When the ropes in atackle system become twisted, there is anincrease in friction and chafing of theropes, as well as a possibility of jammingthe blocks. When the hook of the standingblock is fastened to the supporting member,turn the hook so that the fall line leadsdirectly to the leading block or to the sourceof motive power. It is very difficult to pre-vent twisting of a traveling block. It is par-ticularly important when the tackle isbeing used for a long pull along the ground,such as in dragging logs or timbers.

Antiwisting DevicesOne of the simplest antitwisting devices forsuch a tackle is a short iron rod or apiece of pipe lashed to the traveling block(see Figure 3-15, page 3-18). You can lashthe antitwisting rod or pipe to the shell ofthe block with two or three turns of rope. Ifit is lashed to the becket of the block, youshould pass the rod or pipe between theropes without chafing them as the tackle ishauled in.

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TACKLE

Tackle systems may be either simple or com-pound.

SIMPLE TACKLE SYSTEMSA simple tackle system uses one rope andone or more blocks. To determine the MA ofa simple system, count the number of linessupporting the load (or the travelingblock) (see Figure 3-16). In counting,include the fall line if it leads out of a travel-ing block. In a simple tackle system, the MAalways will be the same as the number oflines supporting the load. As an alternatemethod, you can determine the MA by trac-ing the forces through the system. Beginwith a unit force applied to the fall line.Assume that the tension in a single rope isthe same throughout and therefore the sameforce will exist in each line. Total all theforces acting on the load or traveling block.The ratio of the resulting total force actingon the load or traveling block to the originalunit force exerted on the fall line is the theo-retical MA of the simple system.Figure 3-17 shows examples of two meth-ods of determining the ratio of a simpletackle system. They are—

Method I-counting supporting lines.

Method II—unit force.

SYSTEMS

Method I—Counting Supporting LinesThere are three lines supporting the travel-ing block, so the theoretical MA is 3:1.

Method II—Unit ForceAssuming that the tension on a single ropeis the same throughout its length, a unitforce of 1 on the fall line results in a total of3 unit forces acting on the traveling block.The ratio of the resulting force of 8 on thetraveling block to the unit force of 1 on thefall line gives a theoretical MA of 3:1.

COMPOUND TACKLE SYSTEMSA compound tackle system uses more thanone rope with two or more blocks (see Figure3-18, page 3-20). Compound systems aremade up of two or more simple systems.The fall line from one simple system is fas-tened to a hook on the traveling block ofanother simple system, which may includeone or more blocks. In compound systems,you can best determine the MA by using theunit-force method. Begin by applying a unitforce to the fall line. Assume that the ten-sion in a single rope is the same throughoutand therefore the same force will exist ineach line. Total all the forces acting on the

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traveling block and transfer this force intothe next simple system. The ratio of theresulting total force acting on the load ortraveling block to the original unit forceexerted on the fall line is the theoreticalMA of the compound system. Anothermethod, which is simpler but less accuratein some cases, is to determine the MA ofeach simple system in the compound systemand multiplying these together to obtain thetotal MA. Figure 3-19 shows examples of the

two methods of determining the ratio of acompound tackle system. They are—

Method I—unit force.

Method II—multiplying mechanicaladvantages of simple systems.

Method I—Unit ForceAs in method II of simple tackle systems, aunit force of 1 on the fall line results in 4unit forces acting on the traveling block oftackle system A. Transferring the unit forceof 4 into the fall line of simple system Bresults in a total of 16 unit forces (4 lineswith 4 units of force in each) acting on thetraveling block of tackle system B. The ratioof 16 unit forces on the traveling block carry-ing the load to a 1 unit force on the fall linegives a theoretical MA of 16:1.

Method II—Multiplying MAs ofSimple Systems

The number of lines supporting the travel-ing blocks in systems A and B is equal to 4.The MA of each simple system is thereforeequal to 4:1. You can then determine theMA of the compound system by multiplyingtogether the MA of each simple system for aresulting MA of 16:1.

FRICTIONThere is a loss in any tackle system becauseof the friction created by—

The sheave rolling on the pin, the ropesrubbing together.

The rope rubbing against the sheave.

This friction reduces the total lifting power;therefore, the force exerted on the fall linemust be increased by some amount to over-come the friction of the system to lift theload. Each sheave in the tackle system canbe expected to create a resistance equal toabout 10 percent of the weight of the load.

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Example: A load weighing 5,000 pounds is MA of the tackle system. The actual pulllifted by a tackle system that has a MA of required on the fall line would be equal to4:1. The rope travels over four sheaves that the sum of 5,000 pounds (load) and 2,000produce a resistance of 40 percent of 5,000 pounds (friction) divided by 4 (MA) or 1,750pounds or 2,000 pounds (5,000 x 0.40). The pounds.actual pull that would be required on the fall There are other types of resistance thatline of the tackle system is equal to the sum may have to be considered in addition toof the weight of the load and the friction in tackle resistance. FM 20-22 presents athe tackle system divided by the theoretical. thorough discussion of resistance.

Section IV. Chain Hoists and WinchesIn all cases where manpower is used forhoisting, the system must be arranged toconsider the most satisfactory method ofusing that source of power. More men canpull on a single horizontal line along theground than on a single vertical line. On avertical pull, men of average weight canpull about 100 pounds per man and about60 pounds per man on a horizontal. Ifthe force required on the fall line is 300pounds or less, the fall line can leaddirectly down from the upper block of a

CHAIN

Chain hoists provide a convenient and effi-cient method for hoisting by hand underparticular circumstances (see Figure 3-20).The chief advantages of chain hoists arethat—

The load can remain stationary with-out requiring attention.

One person can operate the hoist toraise loads weighing several tons.

The slow lifting travel of a chain hoist per-mits small movements, accurate adjust-ments of height, and gentle handling ofloads. A retched-handle pull hoist is usedfor short horizontal pulls on heavy objects(see Figure 3-21). Chain hoists differ widelyin their MA, depending on their rated capac-ity which may vary from 5 to 250.

TYPES OF CHAIN HOISTSThe three general types of chain hoists for

tackle vertical line. If 300 pounds timesthe MA of the system is not enough to lifta given load, the tackle must be riggedagain to increase the MA, or the fall linemust be led through a leading block to pro-vide a horizontal pull. This will permit morepeople to pull on the line. Similarly, if aheavy load is to be lifted and the fall line isled through a leading block to a winchmounted on a vehicle, the full power avail-able at the winch is multiplied by the MA ofthe system.

HOISTS

vertical operation are the spur gear, screwgear, and differential.

Spur-Gear Chain HoistThis is the most satisfactory chain hoist forordinary operation where a minimum num-ber of people are available to operate thehoist and the hoist is to be used frequently.This type of chain hoist is about 85 percentefficient.

Screw-Gear Chain HoistThe screw-gear chain hoist is about 50 per-cent efficient and is satisfactory where lessfrequent use of the chain hoist is involved.

Differential Chain HoistThe differential chain hoist is only about 35percent efficient but is satisfactory for occa-sional use and light loads.

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LOAD CAPACITY

Chain hoists are usually stamped with theirload capacities on the shell-of the upperblock. The rated load capacity will run fromone-half of a ton upward. Ordinarily, chainhoists are constructed with their lower hookas the weakest part of the assembly. Thisis done as a precaution so that the lowerhook will be overloaded before the chainhoist is overloaded. The lower hook will startto spread under overload, indicating to theoperator that he is approaching the over-load point of the chain hoist. Under ordinary

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circumstances, the pull exerted on a chain the chain are distorted, it indicates thathoist by one or two men will not overload the chain hoist has been heavily over-the hoist. Inspect chain hoists at frequent loaded and is probably unsafe for furtherintervals. Any evidence of spreading of use. Under such circumstances, the chainthe hook or excessive wear is sufficient hoist should be condemned.cause to replace the hook. If the links of

WINCHES

Vehicular-mounted and engine-drivenwinches are used with tackles for hoisting(see Figure 3-22). There are two points toconsider when placing a power-driven winchto operate hoisting equipment. They are—

The angle with the ground that thehoisting line makes at the drum of thehoist.

The fleet angle of the hoisting linewinding on the drum (see Figure 3-23).

The distance from the drum to the firstsheave of the system is the controlling factorin the fleet angle. When using vehicular-mounted winches, place the vehicle in aposition that lets the operator watch theload being hoisted. A winch is most effectivewhen the pull is exerted on the bare drum ofthe winch. When a winch is rated at a capac-ity, that rating applies only as the first layerof cable is wound onto the drum. The winchcapacity is reduced as each layer of cable iswound onto the drum because of the changein leverage resulting from the increaseddiameter of the drum. The capacity of thewinch may be reduced by as much as 50 per-cent when the last layer is being wound ontothe drum.

GROUND ANGLEIf the hoisting line leaves the drum at anangle upward from the ground, the result-ing pull on the winch will tend to lift itclear of the ground. In this case, a leadingblock must be placed in the system at somedistance from the drum to change the direc-tion of the hoisting line to a horizontal ordownward pull. The hoisting line should be

overwound or underwound on the drum asmay be necessary to avoid a reverse bend.

FLEET ANGLEThe drum of the winch is placed so that aline from the last block passing through thecenter of the drum is at right angles to theaxis of the drum. The angle between thisline and the hoisting line as it winds on thedrum is called the fleet angle (see Figure3-23). As the hoisting line is wound in onthe drum, it moves from one flange to theother so that the fleet angle changes duringthe hoisting process. The fleet angle shouldnot be permitted to exceed 2 degrees andshould be kept below this, if possible. A 1 1/2-degree maximum angle is satisfactory andwill be obtained if the distance from thedrum to the first sheave is 40 inches foreach inch from the center of the drum to theflange. The wider the drum of the hoist thegreater the lead distance must be in placingthe winch.

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SPANISH WINDLASSIn the absence of mechanical power or anappropriate tackle, you may have to usemakeshift equipment for hoisting or pulling.You can use a Spanish windlass to move aload along the ground, or you can direct thehorizontal pull from the windlass throughthe blocks to provide a vertical pull on aload. In making a Spanish windlass, fastena rope between the load you are to move andan anchorage some distance away. Place ashort spar vertically beside this rope, abouthalfway between the anchorage and the load(see Figure 3-24, page 3-26). This spar maybe a pipe or a pole, but in either case itshould have as large a diameter as possible.Make a loop in the rope and wrap it partlyaround the spar. Insert the end of a horizon-tal rod through this loop. The horizontal rodshould be a stout pipe or bar long enough toprovide leverage. It is used as a lever toturn the vertical spar. As the vertical sparturns, the rope is wound around it, whichshortens the line and pulls on the load.Make sure that the rope leaving the verticalspar is close to the same level on both sidesto prevent the spar from tipping over.

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C H A P T E R 4

A n c h o r s a n d G u y L i n e s

Section I.

When heavy loads are handled with atackle, it is necessary to have some meansof anchorage. Many expedient rigginginstallations are supported by combiningguy lines and some type of anchorage sys-tem. Anchorage systems may be either nat-ural or man-made. The type of anchorageto be used depends on the time and mate-rial available and on the holding powerrequired. Whenever possible, natural

Anchors

anchorages should be used so that time,effort, and material can be conserved. Theideal anchorage system must be of suffi-cient strength to support the breakingstrength of the attached line. Lines shouldalways be fastened to anchorages at apoint as near to the ground as possible.The principal factor in the strength of mostanchorage systems is the area bearingagainst the ground.

NATURAL ANCHORSTrees, stumps, or rocks can serve as between two trees to provide a strongernatural anchorages for rapid work in anchorage than a single tree (see Fig-the field. Always attach lines near the ure 4-2, page 4-2). When using rocks asground level on trees or stumps (see Fig- natural anchorages, examine the rocksure 4-1. Avoid dead or rotten trees or carefully to be sure that they are largestumps as an anchorage because they are enough and firmly embedded in thelikely to snap suddenly when a strain is ground (see Figure 4-3, page 4-2). An out-placed on the line. It is always advisable to cropping of rock or a heavy boulder buriedlash the first tree or stump to a second one partially in the ground will serve as a sat-to provide added support. Place a transom is factory anchor.

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MAN-MADE ANCHORSYou must construct man-made anchorswhen natural anchors are not available.These include—

Rock anchors.

Picket holdfasts.

Combination holdfasts.

Deadmen.

ROCK ANCHORSRock anchors have an eye on one end and athreaded nut, an expanding wedge, and astop nut on the other end (see Figure 4-4).To construct a rock anchor, insert thethreaded end of the rock anchor in the holewith the nut’s relation to the wedge asshown in Figure 4-4. After placing the an-chor, insert a crowbar through the eye of therock anchor and twist it. This causes thethreads to draw the nut up against thewedge and force the wedge out against thesides of the hole in the rock. The wedgingaction is strongest under a direct pull;therefore, always set rock anchors so thatthe pull is in a direct line with the shaft ofthe anchor. Drill the holes for rock anchors

5 inches deep. Use a l-inch-diameter drillfor hard rock and a 3/4-inch-diameter drillfor soft rock. Drill the hole as neatly aspossible so that the rock anchor candevelop the maximum strength. In case ofextremely soft rock, it is better to use someother type of anchor because the wedgingaction may not provide sufficient holdingpower.

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PICKET HOLDFASTSA single picket, either steel or wood, can bedriven into the ground as an anchor. Theholding power depends on the—

Diameter and kind of material used.

Type of soil.

Depth and angle in which the picket isdriven.

Angle of the guy line in relation to theground.

Table 4-1 lists the holding capacities of thevarious types of wooden picket holdfasts.Figure 4-5 shows the various picket hold-fasts.


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Single Wooden Pickets first picket to the bottom of the second

Wooden stakes used for pickets should be at picket (see Figure 4-6, B). Then fasten the

least 3 inches in diameter and 5 feet long. rope to the second picket with a clove hitchDrive the picket 3 feet into the ground at an just above the turns. Put a stake betweenangle of 15 degrees from the vertical and the rope turns to tighten the rope by twist-inclined away from the direction of pull (see ing the stake and then driving it into theFigure 4-6). ground (see Figure 4-6, C). This distributes

the load between the pickets. If you use

Multiple Wooden PicketsYou can increase the strength of a holdfastby increasing the area of the picket bearingagainst the ground. Two or more picketsdriven into the ground, spaced 3 to 6 feetapart and lashed together to distribute theload, are much stronger than a single picket(see Figure 4-6, A). To construct the lashing,tie a clove hitch to the top of the first picketwith four to six turns around the first andsecond pickets, leading from the top of the

more than two pickets, make a similar lash-ing between the second and third pickets(see Figure 4-6, D). If you use wire rope forlashing, make only two complete turnsaround each pair of pickets. If neither fiberrope nor wire rope is available for lashing,place boards from the top of the front picketto the bottom of the second picket and nailthem onto each picket (see Figure 4-7). Asyou place pickets farther away from thefront picket, the load to the rear pickets isdistributed more unevenly. Thus, the prin-


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cipal strength of a multiple-picket holdfastis at the front pickets. Increase the capacityof a holdfast by using two or more pickets toform the front group. This increases boththe bearing surface against the soil and theBS.

Steel-Picket HoldfastsA standard steel-picket holdfast consists ofa steel box plate with nine holes drilledthrough it and a steel eye welded on the endfor attaching a guy line (see Figure 4-8, page4-6). The pickets are also steel and aredriven through the holes in a way thatclinches the pickets in the ground. Thisholdfast is especially adapted for anchoringhorizontal lines, such as the anchor cable ona ponton bridge. Use two or more of theseunits in combination to provide a strongeranchorage. You can improvise a similarholdfast with a chain by driving steel pick-ets through the chain links in a crisscross

pattern. Drive the rear pickets in first tosecure the end of the chain; then, install thesuccessive pickets so that there is no slackin the chain between the pickets. A lashedsteel-picket holdfast consists of steel picketslashed together with wire rope the same asfor a wooden-stake picket holdfast (see Fig-ure 4-9, page 4-6). As an expedient, any mis-cellaneous light-steel members can bedriven into the ground and lashed togetherwith wire rope to form an anchorage.

Rock Holdfasts

You can place a holdfast in rock by drillinginto the rock and driving the pickets into theholes. Lash the pickets together with achain (see Figure 4-10, page 4-7). Drill theholes about 3 feet apart, in line with the guyline. The first, or front, hole should be 2 1/2to 3 feet deep and the rear hole, 2 feet deep.Drill the holes at a slight angle, inclinedaway from the direction of the pull.


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COMBINATION HOLDFASTSFor heavy loading of an anchorage, spreadthe load over the largest possible area ofground. Do this by increasing the number ofpickets used. Place four or five multiplepicket holdfasts parallel to each other with aheavy log resting against the front pickets toform a combination log and picket holdfast(see Figure 4-11). Fasten the guy line oranchor sling to the log that bears against thepickets. The log should bear evenly againstall pickets to obtain maximum strength.Select the timber carefully so it can with-stand the maximum pull on the line withoutappreciable bending. Also, you could use asteel cross member to form a combinationsteel-picket holdfast (see Figure 4-12, page4-8).

ConstructionYou can construct a deadman from a log, arectangular timber, a steel beam, or a simi-lar object buried in the ground with a guyline or sling attached to its center. This guyline or sling leads to the surface of theground along a narrow upward slopingtrench. The holding power of a deadman isaffected by—

Its frontal bearing area.

Its mean (average) depth.

DEADMENA deadman is one of the best types ofanchorages for heavy loads or permanentinstallations because of its great holdingpower.


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The angle of pull. withstand the BS of the line attached to it.

The deadman material.In constructing a deadman, dig a hole atright angles to the guy line and undercut 15

The soil condition. degrees from the vertical at the front of thehole facing the load (see Figure 4-13, page

The holding power increases progressively 4-8). Make the guy line as horizontal as pos-as you place the deadman deeper and as the sible, and ensure that the sloping trenchangle of pull approaches a horizontal posi- matches the slope of the guy line. The maintion (see Table 4-2, page 4-8). The holding or standing part of the line leads from thepower of a deadman must be designed to bottom of the deadman. This reduces the


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tendency to rotate the deadman upward out the wire-rope clips above the ground forretightening and maintenance.of the hole. If the line cuts into the ground,

place a log or board under the line at theoutlet of the sloping trench. When usingwire-rope guy lines with a wooden dead-man, place a steel bearing plate on thedeadman where the wire rope is attached toavoid cutting into the wood. Always place

Terms

Table 4-3 lists the terms used in designing adeadman.


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Formulas Given: l-inch-diameter 6-by-19 IPS ropeThe following formulas are used in designinga deadman:

MD = 7 feet

B Ar= B S SR = 1.3

BArE L = D WST = 2 feet

HP

TL = EL+ WST

VD= MD+ D 2

HD =VDS R

A sample problem for designing a deadmanis as follows:

Requirement I: Determine the lengthand thickness of a rectangular timberdeadman if the height of the face avail-able is 18 inches (1 1/2 feet).

BS of wire rope = 83,600 psf (see Table1-2)

HP= 8,000 psf (see Table 4-2)


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Note: Design the deadman so it canwithstand a tension equal to theBS of the wire rope

BAr = BS = 83,600 pounds = 10.5 feet 2

HP 8,000 psf

BA r = 10.5 feet2

EL = face height 1.5 feet= 7 feet

TL = EL + WST = 7 feet + 2 feet = 7 feet

Conduct a final check to ensure that therectangular timber will not fail by bendingby doing a length-to-thickness ratio (L/t),which should be equal to or less than 9.Determine the minimum thickness by L/t =9 and solve for (t):

—= 9L1 t

9 = 9t

9= -9 = l feet

Thus, an 18-inch by 12-inch by 9-foot timberis suitable.

Requirement II: Determine the lengthof a log deadman with a diameter of 21/2 feet.

EL = = = 4.2 feetBAr

D 10.5feet 2

2.5 feet

TL = EL + WST = 4.2 feet + 2 feet = 6.2 feet

Conduct a final check to ensure that the logwill not fail by bending by doing a length-to-diameter ratio (L/d), which should be equal

to or less than 5. The ratio for RequirementII would be equal to L/d = 6.2/2.5 = 2.5.Since this is less than 5, the log will not failby bending.

Length-to-Diameter RatioIf the length-to-diameter ratios for a log or arectangular timber are exceeded, you mustdecrease the length requirements. Use oneof the following methods to accomplish this:

Increase the mean depth.

Increase the slope ration (the guy linebecomes more horizontal).

Increase the thickness of the deadman.

Decrease the width of the slopingtrench, if possible.

NOMOGRAPH-DESIGNED DEADMENNomography and charts have been preparedto facilitate the design of deadmen in thefield. The deadmen are designed to resistthe BS of the cable. The required length andthickness are based on allowable soil bear-ing with 1-foot lengths added to compensatefor the width of the cable trench. Therequired thickness is based on a L/d ratio ofs for logs and a L/d ratio of 9 for cut timber.

Log DeadmanA sample problem for designing a log dead-man is as follows:

Given: 3/4-inch IPS cable. You mustbury the required deadman 5 feet at aslope of 1:4.

Solution: With this information,use the nomograph to determine thediameter and length of the deadmanrequired (see Figure 4-14). Figure 4-15,page 4-12, shows the steps, graphi-cally, on an incomplete nomograph.Lay a straightedge across section A-A


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(left-hand scale) on the 5-foot depth at up from the intersection on the log anddeadman and 1:4 slope and on 3/4-inch read the length of deadman required. InIPS on B-B. Read across the straightedge this case, the deadman must be over 5and locate a point on section C-C. Then 1/2 feet long. Be careful not to select ago horizontally across the graph and log deadman in the darkened area ofintersect the diameter of the log dead- the nomograph because a log from thismen available. Assume that a 30-inch area will fail by bending.diameter log is available. Go vertically


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Rectangular Timber DeadmanA sample problem for designing a rectangu-lar timber deadman is as follows:

Given: 3/4-inch IPS cable. You are tobury the deadman 5 feet at a slope of1:4.

Solution: Use the same 1:4 slope and5-foot depth, along with the procedureto the left of the graph, as in theprevious problem (see Figure 4-14, page4-11). At C-C, go horizontally acrossthe graph to the timber with an 18-inchface. Reading down (working with cuttimber), you can see that the length is 8feet 6 inches and that the minimumthickness is 11 1/2 inches. None of thetimber sizes shown on the nomographwill fail due to bending.

Horizontal DistanceUse the following formula to determine thedistance behind the tower in which deadmenare placed:

Horizontal distance = tower height + deadman depthslope ratio

A sample problem for determining the hori-zontal distance behind a tower is as follows:

deadman depth = 7ft = 28ftslope ratio 1:4

BEARING PLATESTo prevent the cable from cutting into thewood, place a metal bearing plate on thedeadman. The two types of bearing platesare the flat bearing plate and the formedbearing plate, each with its particularadvantages. The flat bearing plate is easilyfabricated, while the formed or shaped platecan be made of much thinner steel.

Flat Bearing PlateA sample problem in the design of flat bear-ing plates is as follows:

Given: 12-inch by 12-inch timber3/4-inch IPS cableSolution: Enter the graph (see Figure4-16, page 4-14) from the left of the 3/4-inch cable and go horizontally acrossthe graph to intersect the line marked12-inch timber, which shows that theplate will be 10 inches wide. (The bear-ing plate is made 2 inches narrowerthan the timber to prevent cutting intothe anchor cable.) Drop vertically anddetermine the length of the plate,which is 9 1/2 inches. Go to the top,

Given: The tower height is 25 feet 4 1/4 vertically along the line to where itinches, and the deadman depth is 7 feet intersects with 3/4-inch cable, andwith a 1:4 slope. determine the minimum required

Solution:

25 ft 4 1/4 in + 7 ft =

1:4

thickness, which is 1 1/16 inches.Thus, the necessary bearing plate mustbe 1 1/16 inches by 9 1/2 inches by 10inches.

32ft 4 1/4 in1:4 = 129 ft 5 in

Formed Bearing Plate

129 feet behind the The formed bearing plates are either curvedto fit logs or formed to fit rectangular tim-ber. In the case of a log, the bearing plate

Place the deadmantower.

Note: The horizontal distance must go half way (180 degrees) around thewithout a tower is as follows: log. For a shaped timber, the bearing plate


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extends the depth of the timber with an inches. If you use a log, the width ofextended portion at the top and the bottom the bearing plate is equal to half the(see Figure 4-17). Each extended portion circumference of the log.should be half the depth of the timber.

A sample problem for designing a formedbearing plate is as follows:

d 2 in this case, 22 inches

Given: 14-inch log or timber with 14-inchface and 1 1/8 MPS cable. d 3.14 x 14—= = 21.98 (use 22 inches)2 2Solution: Design a formed bearingplate. Enter the graph on the left at 11/8 MPS and go horizontally across tointersect the 14-inch line (see figure4-17). Note that the lines intersect in 14 inches for the face and 7 inches for the

The bearing plate would therefore be 1/4inch by 12 inches by 22 inches. For a rectan-gular timber, the width of the plate would be

an area requiring a l/4-inch plate. width of each leg, or a total width of 28Drop vertically to the bottom of the inches (see Figure 4-17). The bearing plategraph to determine the length of the would therefore be 1/4 inch by 12 inches byplate, which in this instance is 12 28 inches.


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Section II. Guy Lines

Guy lines are ropes or chains attached to an Angle of the guy line.object to steady, guide, or secure it. Thelines leading from the object or structure areattached to an anchor system (see Fig-ure 4-18). When a load is applied to thestructure supported by the guy lines, a por-tion of the load is passed through each sup-porting guy line to its anchor. The amountof tension on a guy line depends on the—

For example, if the supported structure isvertical, the stress on each guy line is verysmall; but if the angle of the structure is 45degrees, the stress on the guy lines support-ing the structure will increase considerably.Wire rope is preferred for guy lines becauseof its strength and resistance to corrosion.Fiber is also used for guy lines, particularly

Main load. on temporary structures. The number and

Position and weight of the structure. size of guy lines required depends on thetype of structure to be supported and the

Alignment of the guy line with the tension or pull exerted on the guy linesstructure and the main load. while the structure is being used.


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NUMBER OF GUY LINES

Usually a minimum of four guy lines are points in a tiered effect. In such cases,used for gin poles and boom derricks and there might be four guy lines from thetwo for shears. The guy lines should be center of a long pole to anchorage onevenly spaced around the structure. In a the ground and four additional guylong, slender structure, it is sometimes lines from the top of the pole to anchor-necessary to provide support at several age on the ground.

TENSION ON GUY LINES

You must determine the tension that will beexerted on the guy lines beforehand to selectthe proper size and material you will use.The maximum load or tension on a guy linewill result when a guy line is in direct linewith the load and the structure. Considerthis tension in all strength calculations ofguy lines. You can use the following formulato determine the tension for gin poles andshears (see Figure 4-19, page 4-18):

T = (WL + 1/2W3) DY

T = Tension in guy line

W L = Weight of the load

W 3 = Weight of spar(s)

D = Drift distance, measured from the base ofthe gin pole or shears to the center of the sus-pended load along the ground.

Y= Perpendicular distance from the rear guyline to the base of the gin pole or, for a shears,to a point on the ground midway between theshear legs.

A sample problem for determining the ten-sion for gin poles and shears follows:

Requirement I: gin pole.

Given: WL = 2,400 lbW 3= 800 lbD = 20

Solution:

T = ( WL + 1/2W3) D

= (2,400 + 1/2 (800)) 20Y 28

= 2,000 pounds of tension in the rearor supporting guy line

Requirement II: shears.

Given: The same conditions exist as inRequirement I except that there aretwo spars, each one weighing 800pounds.

Solution:

(WL + 1/2W3)D)T = = (2, 400 + 1/2 (800)) 20

Y Y

= 2,285 pounds

NOTE: The shears produced agreater tension in the rear guyline due to the weight of an addi-tional spar.


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SIZE OF GUY LINES

The size of the guy line to use will depend on must incorporate the appropriate FSs.the amount of tension placed on it. Since Therefore, choose a rope for the guy linethe tension on a guy line may be affected by that has a SWC equal to or greater than theshock loading (and its strength affected by tension placed on the guy line.knots, sharp bends, age, and condition), you

ANCHORAGE REQUIREMENTSAn ideal anchorage system should be least a 1-1 combination (1,400-pound capac-designed to withstand a tension equal to the it y in ordinary soil). Anchor the guy line asBS of the guy line attached to it. If you use a far as possible from the base of the installa-3/8-inch-diameter manila rope as a guy line, tion to obtain a greater holding power fromthe anchorage must be capable of withstand- the anchorage system. The recommendeding a tension of 1,350 pounds, which is the minimum distance from the base of theBS of the 3/8-inch diameter manila rope. If installation to the anchorage for the guy lineyou use picket holdfasts, you will need at is twice the height of the installation.


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C H A P T E R 5

L i f t i n g a n d M o v i n g E q u i p m e n t

Section I. Lifting Equipment

Equipment used for lifting includes gin includes pole, brave, and jinniwink der-poles, tripods, shears, boom derricks, and ricks.stiff leg derricks. Light hoisting equipment

GIN POLESA gin pole consists of an upright spar that isguyed at the top to maintain it in a verticalor nearly vertical position and is equippedwith suitable hoisting tackle. The verticalspar may be of timber, a wide-flange steel-beam section, a railroad rail, or similarmembers of sufficient strength to supportthe load being lifted. The load may behoisted by hand tackle or by hand- orengine-driven hoists. The gin pole is usedwidely in erection work because of the easewith which it can be rigged, moved, andoperated. It is suitable for raising loads ofmedium weight to heights of 10 to 50 feetwhere only a vertical lift is required. Thegin pole may also be used to drag loads hori-zontally toward the base of the pole whenpreparing for a vertical lift. It cannot bedrifted (inclined) more than 45 degrees fromthe vertical or seven-tenths the height ofthe pole, nor is it suitable for swinging theload horizontally. The length and thicknessof the gin pole depends on the purpose forwhich it is installed. It should be no longerthan 60 times its minimum thicknessbecause of its tendency to buckle under com-pression. A usable rule is to allow 5 feet ofpole for each inch of minimum thickness.Table 5-1, page 5-2, lists values when using

spruce timbers as gin poles, with allow-ances for normal stresses in hoisting oper-ations.

RIGGING GIN POLES

In rigging a gin pole, lay out the pole withthe base at the spot where it is to beerected. To make provisions for the guylines and tackle blocks, place the ginpole on cribbing for ease of lashing. Figure4-18, page 4-16, shows the lashing on top ofa gin pole and the method of attachingguys. The procedure is as follows:

Make a tight lashing of eight turns offiber rope about 1 foot from the top ofthe pole, with two of the center turnsengaging the hook of the upper blockof the tackle. Secure the ends of thelashing with a square knot. Nailwooden cleats (boards) to the poleflush with the lower and upper sidesof the lashing to prevent the lashingfrom slipping.

Lay out guy ropes, each four times thelength of the gin pole. In the center ofeach guy rope, form a clove hitch over

Lifting and Moving Equipment 5-1

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the top of the pole next to the tacklelashing. Be sure to align the guy linesin the direction of their anchors (seeFigure 5-1).

Lash a block to the gin pole about 2 feetfrom the base of the pole, the same asfor the tackle lashing at the top, andplace a cleat above the lashing to pre-vent slipping. This block serves as aleading block on the fall line, whichallows a directional change of pull fromthe vertical to the horizontal. A snatchblock is the most convenient type to usefor this purpose.

Reeve the hoisting tackle, and use theblock lashed to the top of the pole sothat the fall line can be passed throughthe leading block at the base of the ginpole.

Drive a stake about 3 feet from thebase of the gin pole. Tie a rope fromthe stake to the base of the pole below

the lashing on the leading block andnear the bottom of the pole. This pre-vents the pole from skidding while youerect it.

Check all lines to be sure that they arenot snarled. Check all lashings to seethat they are made up properly andthat all knots are tight. Check thehooks on the blocks to see that they aremoused properly. You are now readyto erect the gin pole.

ERECTING GIN POLESYou can easily raise a 40-foot-long gin poleby hand (see Figure 5-2). However, youmust raise longer poles by supplementaryrigging or power equipment. The number ofpeople needed to erect a gin pole depends onthe weight of the pole. The procedure is asfollows:

Dig a hole about 2 feet deep for thebase of the gin pole.

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String out the guys to their respectiveanchorages and assign a person to eachanchorage to control the slack in theguy line with a round turn around theanchorage as the pole is raised. If ithas not been done already, install ananchorage for the base of the pole.

Use the tackle system that was used toraise and lower the load to assist inraising the gin pole, if necessary; how-ever, the preferred method is to attachan additional tackle system to the rearguy line. Attach the running block ofthe rear guy-line tackle system to therear guy line, the end of which is at thispoint of erection near the base of thegin pole (see Figure 4-18, page 4-16).Secure the fixed or stationary block tothe rear anchor. The fall line shouldcome out of the running block to givegreater MA to the tackle system.Stretch the tackle system to the base ofthe gin pole before erecting it to pre-vent the tackle blocks from chocking.

Haul in on the fall line of the tacklesystem, keeping a slight tension on therear guy line and on each of the sideguy lines, while eight people (more forlarger poles) raise the top of the pole byhand until the tackle system can takecontrol (see Figure 5-2, page 5-3).

Keep the rear guy line under tension toprevent the pole from swinging and

throwing all of its weight on one of theside guys.

Fasten all guy lines to their anchor-ages with the round turn and two halfhitches when the pole is in its finalposition, approximately vertical orinclined as desired. At times, you mayhave to double the portion of rope usedfor the half hitches.

Open the leading block at the base ofthe gin pole and place the fall line fromthe tackle system through it. Whenthe leading block is closed, the gin poleis ready for use. If you have to driftthe top of the pole without moving thebase, do it when there is no load onthe pole, unless the guys are equippedwith tackle.

OPERATING GIN POLESThe gin pole is particularly adapted to verti-cal lifts (see Figure 5-3). Sometimes it isused for lifting and pulling at the same timeso that the load being moved travels towardthe gin pole just off the ground. When usedin this manner, attach a snubbing line ofsome kind to the other end of the load beingdragged; keep it under tension at all times.Use tag lines to control loads that you arelifting vertically. A tag line is a light linefastened tounder slight

one end of the load and kepttension during hoisting.

TRIPODSA tripod consists of three legs lashed or one-half times that of shears made of thesecured at the top. The advantage of the tri- same size material.pod over other rigging installations is thatit is stable and requires no guy lines tohold it in place. Its disadvantage is that the RIGGING TRIPODS

load can be moved only up and down. The The two methods of lashing a tripod, eitherload capacity of a tripod is about one and of which is suitable provided the lashing

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material is strong enough, are discussedbelow. The material used for lashing can befiber rope, wire rope, or chain. Metal ringsjoined with short chain sections and largeenough to slip over the top of the tripod legsalso can be used.

Method 1

This method is for fiber rope, 1 inch in diam-eter or smaller. Since the strength of the tri-pod is affected directly by the strength of therope and the lashing used, use more turnsthan described here for extra heavy loadsand fewer turns for light loads. The proce-dure is as follows:

Select three spars, about equal in size,and place a mark near the top of eachto indicate the center of the lashing.

Lay two of the spars parallel with theirtops resting on a skid or block and athird spar between the first two, withthe butt in the opposite direction andthe lashing marks on all three in line.The spacing between spars should beabout one-half the diameter of thespars. Leave space between the sparsso that the lashing will not be drawntoo tight when erecting the tripod.

Make a clove hitch (using a l-inchrope) around one of the outside sparsabout 4 inches above the lashing mark,and take eight turns of the line aroundthe three spars (see Figure 5-4, A). Besure to maintain the space between thespars while making the turns.

Finish the lashing by taking two closefrapping turns around the lashingbetween each pair of spars. Secure theend of the rope with a clove hitch onthe center spar just above the lashing.Do not draw the frapping turns tootight.

Method HYou can use this method when using slenderpoles that are not more than 20 feet long orwhen some means other than hand power isavailable for erection (see figure 5-4, B). Theprocedure is as follows:

Lay the three spars parallel to eachother with an interval between themslightly greater than twice the diame-ter of the rope you use. Rest the tops ofthe poles on a skid so that the endsproject over the skid about 2 feet andthe butts of the three spars are in line.Put a clove hitch on one outside leg atthe bottom of the position that the lash-ing will occupy, which is about 2 feet


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from the end. Weave the line over themiddle leg, under and around the outerleg, under the middle leg, and over andaround the first leg; continue thisweaving for eight turns. Finish with aclove hitch on the outer leg.

ERECTING TRIPODS

Spread the legs of a tripod in its final posi-tion so that each leg is equidistant from theothers (see Figure 5-5). This spread shouldnot be less than one-half nor more than two-thirds of the length of the legs. Use chain,rope, or boards to hold the legs in this posi-tion. You can lash a leading block for the fallline of the tackle to one of the legs. The pro-cedure is as follows:

Raise the tops of the spars about 4 feet,keeping the base of the legs on theground.

Cross the two outer legs. The third orcenter leg then rests on top of the cross.With the legs in this position, pass asling over the cross so that it passesover the top or center leg and aroundthe other two.

Hook the upper block of a tackle to thesling and mouse the hook.

Continue raising the tripod by pushingin on the legs as they are lifted at thecenter. Eight people should be able toraise an ordinary tripod into position.

Place a rope or chain lashing betweenthe tripod legs to keep them from shift-ing once they are in their final position.

ERECTING LARGE TRIPODSFor larger tripod installations, you may haveto erect a small gin pole to raise the tripodinto position. Erect the tripods that arelashed in the manner described in Method II

(with the three legs laid together) by raisingthe tops of the legs until the legs clear theground so they can be spread apart. Useguy lines or tag lines to assist in steadyingthe legs while raising them. Cross the outerlegs so that the center leg is on top of thecross, and pass the sling for the hoistingtackle over the center leg and around thetwo outer legs at the cross.


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SHEARSShears made by lashing two legs togetherwith a rope are well adapted for liftingheavy machinery or other bulky loads. Theyare formed by two members crossed at theirtops, with the hoisting tackle suspendedfrom the intersection. Shears must beguyed to hold them in position. Shears arequickly assembled and erected. Theyrequire only two guys and are adapted toworking at an inclination from the vertical.The legs of the shears may be round poles,timbers, heavy planks, or steel bars, depend-ing on the material at hand and the purposeof the shears. In determining the size of themembers to use, the load to be lifted and theratio (L/d) of the legs are the determiningfactors. For heavy loads, the L/d should notexceed 60 because of the tendency of the legsto bend rather than to act as columns. Forlight work, you can improvise shears fromtwo planks or light poles bolted together andreinforced by a small lashing at the intersec-tion of the legs.

RIGGING SHEARSWhen the shears are erected, the spread ofthe legs should equal about one-half theheight of the shears. The maximum allow-able drift is 45 degrees. Tackle blocks andguys for shears are essential. You cansecure the guy ropes to firm posts or treeswith a turn of the rope so that the length ofthe guys can be adjusted easily. The proce-dure is as follows:

Lay two timbers together on theground in line with the guys, with thebutt ends pointing toward the back guyand close to the point of erection.

Place a large block under the tops ofthe legs just below the point of lashingand insert a small spacer blockbetween the tops at the same point (seeFigure 5-6). The separation between

the legs at this point should be equal toone-third the diameter of one leg tomake handling of the lashing easier.

With sufficient l-inch rope for 14 turnsaround both legs, make a clove hitcharound one spar and take eight turnsaround both legs above the clove hitch(see Figure 5-6). Wrap the turnstightly so that the lashing is smoothand without kinks.

Finish the lashing by taking two frap-ping turns around the lashing betweenthe legs and securing the end of therope to the other leg just below thelashing. For handling heavy loads,increase the number of lashing turns.

ERECTING SHEARS

Dig the holes at the points where the legs ofthe shears are to stand. If placed on rockyground, make sure that the base for theshears is level. Cross the legs of the shearsand place the butts at the edges of the holes.With a short length of rope, make two turnsover the cross at the top of the shears and tiethe rope together to form a sling. Be sure tohave the sling bearing against the spars andnot on the shears lashing entirely. The pro-cedure is as follows:

Reeve a set of blocks and place thehook of the upper block through thesling. Secure the sling in the hook bymousing. Fasten the lower block to oneof the legs near the butt so that it willbe in a convenient position when theshears have been raised but will be outof the way during erection.

Rig another tackle in the back guy nearits anchorage if you use the shears onheavy lifts. Secure the two guys to the


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top of the shears with clove hitches tolegs opposite their anchorages abovethe lashing.

Lift the top end of the shears legs and“walk” them up by hand until thetackle on the rear guy line can takeeffect (see Figure 5-7, page 5-10). Itwill take several people (depending onthe size of the shears) to do this. Thenraise the shears legs into final positionby hauling in on the tackle. Secure thefront guy line to its anchorage beforeraising the shears legs, and keep aslight tension on this line to controlmovement.

Keep the legs from spreading by con-necting them with rope, a chair, orboards. It may be neceesary, undersome conditions, to anchor each leg ofthe shears while erecting them to keepthe legs from sliding in the wrongdirection.

OPERATING SHEARSThe rear guy is a very important part of theshears rigging, since it is under a consider-able strain during hoisting. To avoid guy-line failure, design them according to theprinciples discussed in Chapter 4, Section II.The front guy has very little strain on it and


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is used mainly to aid in adjusting the loads, the fall line of the tackle of the shearsdrift and to steady the top of the shears can be led straight out of the upper block.when hoisting or placing the load. You may When handling heavy loads, you may havehave to rig a tackle in the rear guy for to lash a snatch block near the base of one ofhandling heavy loads. During opera- the shear legs to act as a leading block (seetion, set the desired drift by adjusting Figure 5-8). Run the fall line through thethe rear guy, but do not do this while a leading block to a hand- or power-operatedload is on-the shears. For handling light winch for heavy loads.


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BOOM DERRICKS

A boom derrick is a lifting device that incor- swing more than 180 degrees when it is setporates the advantages of a gin pole and the on a turn plate or turn wheel.long horizontal reach of a boom. Use theboom derrick to lift and swing medium-size RIGGING BOOM DERRICKSloads in a 90-degree arc on either side of theresting position of the boom, for a total For hoisting medium loads, rig a boom to

swing of 180 degrees. When employing a swing independently of the pole. Take

boom derrick in lifting heavy loads, set it oncare to ensure the safety of those using theinstallation. Use a boom only temporarily

a turn plate or turn wheel to allow the mast or when time does not permit a more sta-and boom to swing as a unit. A mast is a ble installation. When using a boom on agin pole used with a boom. The mast can gin pole, more stress is placed on the rear


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guy; therefore, you may need a stronger guy.In case larger rope is not at hand, use a setof tackle reeved with the same size rope asthat used in the hoisting tackle as a guy lineby extending the tackle from the top of thegin pole to the anchorage. Lash the blockattached to the gin pole at the point wherethe other guys are tied and in the samemanner. The procedure is as follows:

Rig a gin pole as described on page 5-1,but lash another block about 2 feetbelow the tackle lashing at the top ofthe pole (see Figure 5-9). Reeve thetackle so that the fall line comes fromthe traveling block instead of thestanding block. Attach the travelingblock to the top end of the boom aftererecting the gin pole.

Erect the gin pole in the mannerdescribed on page 5-1, but pass the fallline of the tackle through the extrablock at the top of the pole before erect-ing it to increase the MA of the tacklesystem.

Select a boom with the same diameterand not more than two-thirds as longas the gin pole. Spike two boards to thebutt end of the boom and lash themwith rope, making a fork (see Figure5-9). Make the lashing with a mini-mum of sixteen turns and tie it off witha square knot. Drive wedges under thelashing next to the cleats to help makethe fork more secure (see Figure 5-9).

Spike cleats to the mast about 4 feetabove the resting place of the boom andplace another block lashing just abovethese cleats. This block lashing willsupport the butt of the boom. If a sepa-rate tackle system is rigged up to sup-port the butt of the boom, place anadditional block lashing on the boomjust below the larger lashing to securethe running block of the tackle system.

Use manpower to lift the boom in placeon the mast through the sling that willsupport it if the boom is light enough.The sling consists of two turns of ropewith the ends tied together with asquare knot. The sling should passthrough the center four turns of theblock lashing on the mast and shouldcradle the boom. On heavier booms,use the tackle system on the top of themast to raise the butt of the boom tothe desired position onto the mast.

Lash the traveling block of the gin poletackle to the top end of the boom asdescribed on page 5-1, and lash thestanding block of the boom tackle atthe same point. Reeve the boom tackleso that the fall line comes from thestanding block and passes through theblock at the base of the gin pole. Theuse of the leading block on this fall lineis optional, but when handling heavyloads, apply more power to a horizontalline leading from the block with lessstrain on the boom and guys.


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ERECTING BOOM DERRICKS

Raise the boom into position when the rig-ging is finished. When working with heavyloads, rest the base of the boom on theground at the base of the pole. Use a morehorizontal position when working with lightloads. In no case should the boom bearagainst any part of the upper two-thirds ofthe mast.

OPERATING BOOM DERRICKS

A boom on a gin pole provides a convenientmeans for loading and unloading trucks or

STIFF-LEGThe mast of a stiff-leg derrick is held in thevertical position by two rigid, inclined strutsconnected to the top of the mast. The strutsare spread 60 to 90 degrees to provide sup-port in two directions and are attached tosills extending from the bottom of the mast.The mast is mounted on vertical pins. Themast and boom can swing through an arc ofabout 270 degrees. The tackles for hoistingthe load and raising the boom are similar tothose used with the boom and gin pole (seepage 5-11, Rigging Boom Derrick).

OPERATING STIFF-LEG DERRICKSA stiff-leg derrick equipped with a long boomis suitable for yard use for unloading andtransferring material whenever continuousoperations are carried on within reach of itsboom. When used on a bridge deck, movethese derricks on rollers. They are sometimesused in multistory buildings surmounted bytowers to hoist material to the roof of themain building to supply guy derricks

flatcars when the base of the gin pole cannotbe set close to the object to be lifted. It isused also on docks and piers for unloadingboats and barges. Swing the boom by push-ing directly on the load or by pulling theload with bridle lines or tag lines. Adjustthe angle of the boom to the mast by haulingon the fall line of the mast tackle. Raise orlower the load by hauling on the fall line ofthe boom tackle. You should place a leadingblock (snatch block) at the base of the ginpole. Lead the fall line of the boom tacklethrough this leadingpower-operated winching of the load.

DERRICKSmounted on the tower.

block to a hand- orfor the actual hoist-

The stiff-leg derrickalso is used where guy lines cannot be pro-vided, as on the edge of a wharf or on abarge.

STEEL DERRICKSSteel derricks of the stiff-leg type are avail-able to engineer troops in two sizes:

A 4-ton rated capacity with a 28-footradius (see Figure 5-10, page 5-14).

A 30-ton rated capacity with a 38-footradius, when properly counter-weighted.

Both derricks are erected on fixed bases.The 4-ton derrick, including a skid-mounted, double-drum, gasoline-engine-driven hoist, weighs 7 tons and occupies aspace 20 feet square. The 30-ton derrick,including a skid-mounted, double-drumhoist, weighs about 22 tons and occupies aspace 29 feet square.

LIGHT HOISTING EQUIPMENTExtended construction projects usually in- members by hand or by light hoisting equip-volve erecting numerous light members as ment, allowing the heavy hoisting equip-well as the heavy main members. Progress ment to move ahead with the erection of thecan be more rapid if you raise the light main members. Very light members can be


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raised into place by two people using manila POLE DERRICKShandlines. When handlines are inadequate The improved pole derrick, called a “dutch-or when members must be raised above the man”, is essentially a gin pole constructedworking level, use light hoisting equipment.Many types of hoisting equipment for lifting

with a sill and knee braces at the bottom(see Figure 5-11, A). It is usually installed

light loads have been devised. Those dis- with guys at the front and back. It is effec-cussed here are only typical examples that tive for lifting loads of 2 tons and, becausecan be constructed easily in the field and of its light weight and few guys, is readilymoved readily about the job. moved from place to place by a small squad.


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BRAVE DERRICKSThe braced derrick, known as a “monkey”, isvery useful for filling in heavy membersbehind the regular erection equipment (seeFigure 5-11, B, page 5-15). Two back guysare usually employed when lifting heavyloads, although light members may be liftedwithout them. Power is furnished by ahand- or power-driven hoist. The construc-tion of the base of the monkey permits it tobe anchored to the structure by lashings toresist the pull of the lead line on the snatchblock at the foot of the mast.

JINNIWINK DERRICKSThis derrick is suitable for lifting loadsweighing 5 tons (see Figure 5-11, C, page5-15). Hand-powered jinniwinks arerigged preferably with manila rope. Thoseoperated by a power-driven hoist shouldbe rigged with wire rope, The jinniwinkis lashed down to the structural frame atboth the front sill and tail sill to preventthe tail sill from rising when a load islifted.

Section II. Moving EquipmentSkids, rollers and jacks are used to move (see Figure 5-12). A firm and level founda-heavy loads. Cribbing or blocking is often tion for cribbing is essential, and the bottomnecessary as a safety measure to keep an timbers should rest firmly and evenly onobject in position or to prevent accidents to the ground. Blocking used as a foundationpeople who work under or near these heavy for jacks should be sound and large enoughobjects. Cribbing is formed by piling tim- to carry the load. The timbers should bebers in tiers, with the tiers alternating in dry, free from grease, and placed firmly ondirection, to support a heavy weight at a the ground so that the pressure is evenlyheight greater than blocking would provide distributed.

SKIDSPlace timber skids longitudinally under Oak planks 2 inches thick and about 15 feetheavy loads either to— long make satisfactory skids for most opera-

Distribute the weight over a greater tions. Keep the angle of the skids low to pre-area. vent the load from drifting or getting out of

control. You can use grease on skids whenMake a smooth surface for skidding only horizontal movement is involved; how-equipment. ever, in most circumstances, greasing is dan-Provide a runway surface when rollers gerous because it may cause the load to driftare used (see Figure 5-13). sideways suddenly.

ROLLERS

Use hardwood or pipe rollers over skids for round and long enough to pass completelymoving very heavy loads into position. under the load being moved. Support thePlace the skids under the rollers to provide a load on longitudinal wooden members tosmooth, continuous surface for the rollers. provide a smooth upper surface for the rollersMake sure that the rollers are smooth and to move on. The skids placed underneath


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the rollers must form continuous support.Ordinarily, place four to six rollers under theload to be moved (see Figure 5-13, page 5-17).

Place several rollers in front of the load androll the load slowly forward onto the rollers.As the load passes, rollers are left clearbehind the load and are picked up and placedin front of the load so that there is a continu-ous path of rollers. In making a turn with aload on rollers, incline the front rollersslightly in the direction of the turn and therear rollers in the opposite direction. Thisinclination of the rollers may be made bystriking them sharply with a sledge. Formoving lighter loads, make up the rollers andset on axles in side beams as a semiperma-nent conveyor. Permanent metal roller con-veyors are available (see Figure 5-14). Theyare usually made in sections.

JACKS

To place cribbing, skids, or rollers, you mayhave to lift and lower the load for a shortdistance. Jacks are used for this purpose.Jacks are used also for precision placementof heavy loads, such as bridge spans. Anumber of different styles of jacks are avail-able, but only use heavy duty hydraulic orscrew-type jacks. The number of jacks usedwill depend on the weight of the load andthe rated capacity of the jacks. Be certainthat the jacks are provided with a solid foot-ing, preferably wooden blocking. Cribbingis frequently used in lifting loads by jackingstages (see Figure 5-15). The procedurerequires—

Blocking the jacks.

Raising the object to the maximumheight of the jacks to permit cribbingto be put directly under the load.

Lowering the load onto the cribbing.

Repeat this process as many times as nec-essary to lift the load to the desired height.

Jacks are available in capacities from 5 to100 tons (see Figure 5-16). Small capacityjacks are operated through a rack bar orscrew, while those of large capacity areusually operated hydraulically.

RATCHET-LEVER JACKSThe ratchet lever jack, available to engi-neer troops as part of panel bridge equip-ment, is a rack-bar jack that has a ratedcapacity of 15 tons (see Figure 5-16, A). Ithas a foot lift by which loads close to itsbase can be engaged. The foot capacity is 71/2 tons.


FM 5-125

STEAMBOAT RATCHETS

Their principal uses are for tightening linesor lashings and for spreading or bracingparts in bridge construction.

SCREW JACKSScrew jacks have a rated capacity of 12 tons(see Figure 5-16, C). They are about 13 incheshigh when closed and have a safe rise of atleast 7 inches. These jacks are issued withthe pioneer set and can be used for generalpurposes, including steel erection.

HYDRAULIC JACKSHydraulic jacks are available in Class IVsupplies in capacities up to 100 tons (seeFigure 5-16, D) Loads normally encounteredby engineer troops do not require large.

Steamboat ratchets (sometimes called push- capacity hydralic jacks. Those supplieding-and-pulling jacks) are ratchet screw with the squad pioneer set are 11 inchesjacks of 10-ton rated capacity with end fit- high and have a rated capacity of 12 tonstings that permit pulling parts together or and a rise of at least 5 1/4 inches. They arepushing them apart (see Figure 5-16, B). large enough for usual construction needs.


FM 5-125

C H A P T E R 6

S c a f f o l d s

Construction jobs may require severalkinds of scaffolds to permit easy workingprocedures. Scaffolds may range from indi-vidual planks placed on structural membersof the building to involved patent scaffold-ing. Scaffold planks are placed as a deckingover—

Swinging scaffolds.

Suspended scaffolds.

Needle-beam scaffolds.

Double-pole, built-up, independentscaffolds.

Scaffold planks are of various sizes, includ-ing 2 inches by 9 inches by 13 feet, 2 inchesby 10 inches by 16 feet, and 2 inches by 12inches by 16 feet. You may need 3-inch-thick scaffold planks for platforms thatmust hold heavy loads or withstand move-ments. Planks with holes or splits are notsuitable for scaffolding if the diameter of

the hole is more than 1 inch or if the splitextends more than 3 inches in from theend. Use 3-inch planks to build the tem-porary floor used for constructing steelbuildings because of the possibility that aheavy steel member might be rested tem-porarily on the planks. Lay single scaffoldplanks across beams of upper floors orroofs to form working areas or runways (seeFigure 6-1, page 6-2). Run each plank frombeam to beam, with not more than a fewinches of any plank projecting beyond theend of the supporting beam. Overhangsare dangerous because people may step onthem and overbalance the scaffold plank.When laying planking continuously, as ina runway, lay the planks so that their endsoverlap. You can stagger single plank runsso that each plank is offset with referenceto the next plank in the run. It is advisableto use two layers of planking on largeworking areas to increase the freedom ofmovement.

SWINGING SCAFFOLDSThe swinging, single plank, or platform SINGLE-PLANK SWINGING SCAFFOLDStype of scaffold must always be secured to A single scaffold plank maybe swung overthe building or structure to prevent it from the edge of a building with two ropes bymoving away and causing someone to fall.When swinging scaffolds are suspended

using a scaffold hitch at each end (see Fig-ures 6-2, page 6-2, and 2-28, page 2-20). A

adjacent to each other, planks should never tackle may be inserted in place of ropes forbe placed so as to form a bridge between lowering and hoisting. This type of swing-them. ing scaffold is suitable for one person.

Scaffolds 6-1

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6-2 Scaffolds

FM 5-125

SWINGING PLATFORM SCAFFOLDS which the lower block of a set of manilarope falls is attached. The scaffold is sup-

The swinging platform scaffold consists of a ported by hooks or anchors on the roof of aframe similar in appearance to a ladder with structure. The fall line of the tackle musta decking of wood slats (see Figure 6-3). It is be secured to a member of the scaffold whensupported near each end by a steel stirrup to in final position to prevent it from falling.

SUSPENDED SCAFFOLDSSuspended scaffolds are heavier than swing- be made up in almost any width up toing scaffolds and are usually supported on about 6 feet and may be 12 feet long,outriggers at the roof. From each outrigger, depending on the size of the putlogs, or lon-cables lead to hand winches on the scaffold. gitudinal supports, under the scaffold. AThis type of scaffold is raised or lowered by light roof may be included on this type ofoperating the hand winches, which must scaffold to protect people from fallingcontain a locking device. The scaffold may debris.

Scaffolds 6-3

FM 5-125

NEEDLE-BEAM SCAFFOLDSThis type of scaffold is used only for tempo-rary jobs. No material should be stored onthis scaffold. In needle-beam scaffolding,two 4- by 6-inch, or similar size, timbers aresuspended by ropes. A decking of 2-inchscaffold plank is placed across the needlebeams, which should be placed about 10 feetapart. Needle-beam scaffolding is oftenused by riveting gangs working on steelstructures because of the necessity for fre-quent changes of location and because ofits adaptability to different situations (see

Figure 6-4). A scaffold hitch is used in therope supporting the needle beams to pre-vent them from rolling or turning over (seeFigure 2-28, page 2-20). The hanging linesare usually of 1 1/4-inch manila rope. Therope is hitched to the needle beam, carriedup over a structural beam or other support,and then down again under the needlebeam so the latter has a complete loop ofrope under it. The rope is then passed overthe support again and fastened arounditself by two half hitches.

DOUBLE-POLE BUILT-UP SCAFFOLDS

The double-pole built-up scaffold (steel orwood), sometimes called the independentscaffold, is completely independent of themain structure. Several types of patentindependent scaffolding are available forsimple and rapid erection (see Figure 6-5).The scaffolding can be built from wood, ifnecessary. The scaffold uprights are bracedwith diagonal members, and the workinglevel is covered with a platform of planks.All bracing must form triangles. The base ofeach column requires adequate footingplates for the bearing area on the ground.Patented steel scaffolding is usually erected

by placing the two uprights on the groundand inserting the diagonal members. Thediagonal members have end fittings thatpermit rapid locking-in position. The firsttier is set on steel bases on the ground. Asecond tier is placed in the same manner onthe first tier, with the bottom of eachupright locked to the top of the lower tier. Athird and fourth upright can be placed onthe ground level and locked to the first setwith diagonal bracing. The scaffolding canbe built as high as desired, but high scaf-folding should be tied in to the main struc-ture.

6-4 Scaffolds

FM 5-125

Scaffolds 6-5

FM 5-125

BOATSWAIN’S CHAIRSBoatswain’s chairs can be made severalways, but they usually consist of a sling forsupporting one person.

ROPE CHAIRYou can make a rope boatswain’s chair byusing a double bowline and a rolling hitch(see Figure 6-6). One person can operate therope seat to lower himself by releasing thegrip of the rolling hitch. A slight twist withthe hand on the hitch permits the suspen-sion line to slip through it, but when thehand pressure on the hitch is released, thehitch will hold firmly.

ROPE CHAIR WITH SEAT

notched board inserted through the two legloops will provide a comfortable seat (seeFigure 6-7). The loop formed as the runningend to make the double bowline will stillprovide a back support, and the rolling hitchcan still be used to lower the boatswain’schair.

ROPE CHAIR WITH TACKLE

The boatswain’s chair is supported by a fourpart rope tackle (two double blocks [see Fig-ure 6-8]). One person can raise or lowerhimself or can be assisted by a person on theground. When working alone, the fall line isattached to the lines between the seat andthe traveling block with a rolling hitch. As a

If the rope boatswain’s chair must be used to safety precaution, a figure-eight knot shouldsupport a person at work for some time, the be tied after the rolling hitch to prevent acci-rope may cause considerable discomfort. A dental untying.

6-6 Scaffolds

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Scaffolds 6-7

FM 5-125

A P P E N D I X

F i g u r e s a n d T a b l e s o f U s e f u l

I n f o r m a t i o n

Figures and Tables of Useful Information A-1

FM 5-125

A-2 Figures and Tables of Useful Information

FM 5-125


FM 5-125

G l o s s a r y

AR

ATTN

BA

bend

bight

BS

CH

CL

cordage

D

D

DA

EL

ENG

FM

FS

Army regulation

attention

bearing area

A bend (in this manual called a knot) is used to fasten two ropestogether or to fasten a rope to a ring or loop.

A bight is a bend or U-shaped curve in a rope.

breaking strength; the greatest strength.

clay, high compressibility

clay, low compressibility

Ropes and twines made by twisting together vegetable or syntheticfibers.

diameter

drift distance

Department of the Army

effective length

engineer

field manual

factor of safety

Glossary-1

FM 5-125

GC

GP

GW

HD

HP

HQ

IPS

L

line

loop

L/d

L/t

MA

MD

MH

ML

MPS

clayey gravel

poorly graded gravel

well-graded gravel

horizontal distance

holding power

headquarters

improved plow steel

length of the sling

A line (sometimes called a rope) is a thread, string, cord, or rope, espe-cially a comparatively slender and strong cord. This manual will usethe word rope rather than line in describing knots, hitches, rigging,and the like.

A loop is formed by crossing the running end cover or under the stand-ing part, forming a ring or circle in the rope.

length-to-diameter ratio

length-to-thickness ratio

mechanical advantage

mean depth

silt, high compressibility

silt, low compressibility

mild plow steel

Glossary-2

FM 5-125

N number of slings

No number

OH organic soil, high compressibility

OL organic soil, low compressibility

overhand turn or loop An overhand turn or loop is made when the running end passesover the standing part.

PS plow steel

psi pound(s) per square inch

rope A rope (often called a line) is a large, stout cord made of strands offiber or wire that are twisted or braided together.

round turn A round turn is a modified turn, but with the running end leaving thecircle in the same general direction as the standing part.

running end The running end is the free or working end of a rope.

SC clayey sandy soil

SF finely graded sand

SP poorly graded sand

SR slope ratio

standing part The standing part is the rest of the rope, excluding the running end.

SW well-graded sand

SWC safe working capacity

Glossary-3

FM 5-125

T tension

TB technical bulletin

TC training circular

TL timber length

TM training manual

TRADOC United States Army Training and Doctrine Command

turn A turn is the placing of a loop around a specific object (such as a post,rail, or ring) with the running end continuing in a direction opposite tothe standing part.

underhand turn or loop An underhand turn or loop is made when the running endpasses under the standing part.

US United States (of America)

V vertical distance

VD vertical distance

W weight of the load to be lifted

W3 width of spar(s)

width of the load

WST width of the sloping trench

WL

Y Perpendicular distance from the rear guy line to the base of the ginpole or, for shears, to a point on the ground midway between theshears legs.

Glossary-4

FM 5-125

R e f e r e n c e s

SOURCES USED

These are the sources quoted or paraphrased in this publication.

Army Publications

Army Regulations (ARs)

AR 59-3. Air Transportation Movement of Cargo by Scheduled Military and Commercial AirTransportation -- CONUS Outbound. 1 February 1981.

Field Manuals (FMs)

FM 5-34. Engineer Field Data. 14 September 1987.

FM 5-434. Earthmoving Operations. 30 September 1992,

FM 10-500-7. Airdrop Derigging and Recovery Procedures. 20 September 1994.

FM 20-22. Vehicle Recovery Operations (FMFRP 4-19). 18 September 1990.

FM 55-9. Unit Air Movement Planning. 5 April 1993.

FM 55-12. Movement of Units in Air Force Aircraft (AFM 76-7; FMFM 4-6; OPNAVINST4630.27A). 10 November 1989,

FM 55-15. Transportation Reference Data. 9 June 1986.

Supply Catalog (SC)

SC 5180-90-CL-N17. Tool Kit Rigging, Wire Rope: Cutting, Clamping, and Splicingw/Chest. 23 October 1981.

Technical Bulletins (TBs)

TB 43-0142. Safety Inspection and Testing of Lifting Devices. 30 August 1993.

TB ENG 317. Air Movement Instructions: Grouping, Modification, Disassembly andReassembly for Crane, Shovel, Truck Mounted, 20 Ton, 3/4 Cubic Yard, GasolineDriven, Garwood Model M-20-B. 28 June 1962.

TB ENG 324. Air Movement Instructions (Grouping, Modification, Disassembly, andReassembly) for Mixer, Concrete, GED, Trailer Mounted (Construction MachineryModel 16S). 2 July 1962.

TB ENG 326. Air Movement Instructions: (Grouping, Modification, Disassembly, andReassembly) for Scraper, Earth Moving, Towed, 12 Cubic Yard, Cable Operated,Letorneau-Westinghouse Model LPO. 9 July 1962.

References-1

FM 5-125

TB ENG 330. Air Movement Instructions (Grouping, Modification, Disassembly, andReassembly) for Truck, Stake: 5-Ton, 6x6; Military Bridging on ORD M-139 Chassis.3 July 1962,

Training Circular (TC)TC 90-6-1, Military Mountaineering. 26 April 1989.

Technical Manuals (TMs)TM 5-270, Cableways, Tramways, and Suspension Bridges. 21 May 1964.TM 10-500-70. Airdrop of Supplies and Equipment: Rigging Dry Bulk Materials and

Potable Water for Free Drop. 2 November 1967.

DOCUMENTS NEEDED

These documents must be available to the intended users of this publication.

Department of the Army (DA) FormsDA Form 2028. Recommended Changes to Publications and Blank Forms. 1 February 1974.

References-2

FM 5-125

I n d e x

Index-1

FM 5-125

Index-2

FM 5-125

Index-3

FM 5-125

Index-4

FM 5-1253 OCTOBER 1995

By Order of the Secretary of the Army:

Official:DENNIS J. REIMER

General, United States ArmyChief of Staff

JOEL B. HUDSONActing Administrative Assistant to the

Secretary of the Army00725

DISTRIBUTION:

Active Army, USAR, and ARNG: To be distributed in accordance with DAForm 12-11 E, requirements for FM 5-125, Rigging Techniques, Procedures, andApplications (Qty rqr block no. 5426)

✰ U.S. GOVERNMENT PRINTING OFFICE: 1995 - 628 - 027 / 40064

PIN: 074097-000

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