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Marine Division92571 Neuilly-sur-Seine Cedex- France

Tel: + 33 (0)1 55 24 70 00 - Fax: + 33 (0)1 55 24 70 25

Marine Website: http://www.veristar.com

Email: [email protected]

2011 Bureau Veritas - All rights reserved

PART D Service Notations

Chapters 13 14 15 16 17 18 19 20 21

NR 467.D3 DT R05 E July 2011

Rules for the Classification of

Steel Ships

Go back to Welcome


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ARTICLE 1

1.1.- BUREAU VERITAS is a Society the purpose of whose Marine Division (the "Society") is the classi-fication (" Classification ") of any ship or vessel or structure of any type or part of it or system therein col-lectively hereinafter referred to as a "Unit" whether linked to shore, river bed or sea bed or not, whetheroperated or located at sea or in inland waters or partly on land, including submarines, hovercrafts, drillingrigs, offshore installations of any type and of any purpose, their related and ancillary equipment, subseaor not, such as well head and pipelines, mooring legs and mooring points or otherwise as decided by theSociety.

The Society:

prepares and publishes Rules for classification, Guidance Notes and other documents (Rules);

issues Certificates, Attestations and Reports following its interventions (Certificates);

publishes Registers.

1.2.- The Society also participates in the application of National and International Regulations or Stand-ards, in particular by delegation from d ifferent Governments. Those activities are hereafter collectively re-ferred to as " Certification ".

1.3.- The Society can also provide services related to Classification and Certification such as ship andcompany safety management certification; ship and port security certification, training activities; all activi-ties and duties incidental thereto such as documentation on any supporting means, software, instrumen-tation, measurements, tests and trials on board.

1.4.- The interventions mentioned in 1.1., 1.2. and 1.3. are referred to as " Services ". The party and/or itsrepresentative requesting the services is hereinafter referred to as the " Client ". The Services are pre-pared and carried out on the assumption that the Clients are aware of the International Maritime

and/or Offshore Industry (the "Industry") practices.

1.5.- The Society is neither and may not be considered as an Underwriter, Broker in ship's sale or char-tering, Expert in Unit's valuation, Consulting Engineer, Controller, Naval Architect, Manufacturer, Ship-builder, Repair yard, Charterer or Shipowner who are not relieved of any of their expressed or impliedobligations by the interventions of the Society.

ARTICLE 2

2.1.- Classification is the appraisement g iven by the Society for its Client, at a certain date, following sur-veys by its Surveyors along the lines specified in Articles 3 and 4 hereafter on the level of compliance ofa Unit to its Rules or part of them. This appraisement is represented by a class entered on the Certificatesand periodically transcribed in the Society's Register.

2.2.- Certification is carried out by the Society along the same lines as set out in Art icles 3 and 4 hereafterand with reference to the applicable National and International Regulations or Standards.

2.3.-It is incumbent upon the Client to maintain the condition of the Unit after surveys, to presentthe Unit for surveys and to inform the Society without delay of circumstances which may affect thegiven appraisement or cause to modify its scope.

2.4.- The Client is to give to the Society all access and information necessary for the safe and efficientperformance of the requested Services. The Client is the sole responsible for the conditions of presenta-

tion of the Unit for tests, trials and surveys and the conditions under which tests and trials are carr ied out.

ARTICLE 3

3.1.- The Rules, procedures and instructions of the Society take into account at the date of theirpreparation the state of currently available and proven technical knowledge of the Industry. Theyare not a standard or a code of construction neither a guide for maintenance, a safety handbookor a guide of professional practices, all of which are assumed to be known in detail and carefullyfollowed at all times by the Client.

Committees consisting of personalities from the Industry contribute to the development of those docu-ments.

3.2. - The Society only is qualified to apply its Rules and to interpret them. Any reference to themhas no effect unless it involves the Society's intervention.

3.3.- The Services of the Society are carried out by professional Surveyors according to the applicableRules and to the Code of Ethics of the Society. Surveyors have authority to decide locally on matters re-lated to classification and certification of the Units, unless the Rules provide otherwise.

3.4.- The operations of the Society in providing its Services are exclusively conducted by way ofrandom inspections and do not in any circumstances involve monitoring or exhaustive verifica-tion.

ARTICLE 4

4.1.- The Society, acting by reference to its Rules:

reviews the construction arrangements of the Units as shown on the documents presented by the Cli-ent;

conducts surveys at the place of their construction;

classes Units and enters their class in its Register;

surveys periodically the Units in service to note that the requirements for the maintenance of class aremet.

The Client is to inform the Society without delay of circumstances which may cause the date or theextent of the surveys to be changed.

ARTICLE 5

5.1. - The Society acts as a provider of services. This cannot be construed as an obligation bearingon the Society to obtain a result or as a warranty.

5.2. - The certificates issued by the Society pursuant to 5.1. here above are a statement on the levelof compliance of the Unit to its Rules or to the documents of reference for the Services providedfor.

In particular, the Society does not engage in any work relating to the design, building, productionor repair checks, neither in the operation of the Units or in their trade, neither in any advisory serv-ices, and cannot be held liable on those accounts. Its certificates cannot be construed as an im-plied or express warranty of safety, fitness for the purpose, seaworthiness of the Unit or of its valuefor sale, insurance or chartering.

5.3. - The Society does not declare the acceptance or commissioning of a Unit, nor of its construc-tion in conformity with its design, that being the exclusive responsibility of its owner or builder,respectively.

5.4.- The Services of the Society cannot create any obligation bearing on the Society or constitute anywarranty of proper operation, beyond any representation set forth in the Rules, of any Unit, equipment ormachinery, computer software of any sort or other comparable concepts that has been subject to any sur-vey by the Society.

ARTICLE 6

6.1.- The Society accepts no responsibility for the use of information related to its Services which was notprovided for the purpose by the Society or with its assistance.

6.2.- If the Services of the Society cause to the Client a damage which is proved to be the directand reasonably foreseeable consequence of an error or omission of the Society, its liability to-wards the Client is limited to ten times the amount of fee paid for the Service having caused thedamage, provided however that this limit shall be subject to a minimum of eight thousand (8,000)Euro, and to a maximum which is the greater of eight hundred thousand (800,000) Euro and oneand a half times the above mentioned fee.

The Society bears no liability for indirect or consequential loss such as e.g. loss of revenue, lossof profit, loss of production, loss relative to other contracts and indemnities for termination of oth-er agreements.

6.3.- All claims are to be presented to the Society in writing within three months of the date when the Serv-ices were supplied or (if later) the date when the events which are relied on of were first known to the Client,and any claim which is not so presented shall be deemed waived and absolutely barred. Time is to be in-terrupted thereafter with the same periodicity.

ARTICLE 7

7.1.- Requests for Services are to be in writing.7.2.- Either the Client or the Society can terminate as of right the requested Services after givingthe other party thirty days' written notice, for convenience, and without prejudice to the provisionsin Article 8 hereunder.

7.3.- The class granted to the concerned U nits and the previously issued certificates remain valid until thedate of effect of the notice issued according to 7.2. here above subject to compliance with 2.3. here aboveand Article 8 hereunder.

7.4.- The contract for classification and/or certification of a Unit cannot be transferred neither assigned.

ARTICLE 8

8.1.- The Services of the Society, whether completed or not, involve, for the part carried out, the paymentof fee upon receipt of the invoice and the reimbursement of the expenses incurred.

8.2. Overdue amounts are increased as of right by interest in accordance with the applicable leg-islation.

8.3. - The class of a Unit may be suspen ded in the event of non -payment of fee after a first unfru itfulnotification to pay.

ARTICLE 9

9.1.- The documents and data provided to or prepared by the Society for its Services, and the informationavailable to the Society, are treated as confidential. However:

clients have access to the data they have provided to the Society and, during the period of classifica-tion of the Unit for them, to the classification fileconsisting of survey reports and certificates whichhave been prepared at any time by the Society for the classification of the Unit;

copy of the documents made available for the classification of the Unit and of available survey reportscan be handed over to another Classification Society, where appropriate, in case of the Unit's transferof class;

the data relative to the evolution of the Register, to the class suspension and to the survey status of theUnits, as well as general technical information related to hull and equipment damages, are passed onto IACS (International Association of Classification Societies) according to the association workingrules;

the certificates, documents and information relative to the Units classed with the Society may bereviewed during certificating bodies audits and are disclosed upon order of the concerned governmen-tal or inter-governmental authorities or of a Court having jurisdiction.

The documents and data are subject to a file management plan.

ARTICLE 10

10.1.- Any delay or shortcoming in the performance of its Services by the Society arising from an eventnot reasonably foreseeable by or beyond the control of the Society shall be deemed not to be a breach ofcontract.

ARTICLE 11

11.1.- In case of diverging opinions during surveys between the Client and the Society's surveyor, the So-ciety may designate another of its surveyors at the request of the Client.

11.2.- Disagreements of a technical nature between the Client and the Society can be submitted by theSociety to the advice of its Marine Advisory Committee.

ARTICLE 12

12.1. - Disputes over the Services carried out by delegation of Governments are assessed within theframework of the applicable agreements with the States, international Conventions and national rules.

12.2.- Disputes arising out of t he payment of the Society's invoices by the Client are submitted to the Courtof Nanterre, France.

12.3.- Other disputes over the present General Conditions or over the Services of the Society areexclusively submitted to arbitration, by three arbitrators, in London according to the ArbitrationAct 1996 or any statutory modification or re-enactment thereof. The contract between the Societyand the Client shall be governed by English law.

ARTICLE 13

13.1.-These General Conditions constitute the sole contractual obligations binding together theSociety and the Client, to the exclusion of all other representation, statements, terms, conditionswhether express or implied. They may be varied in writing by mutual agreement.

13.2. - The invalidity of one or more stipulations of the present General Conditions does not affect the va-lidity of the remaining provisions.

13.3.- The definitions herein take precedence over any definitions serving the same purpose which mayappear in other documents issued by the Society.

BV Mod. Ad. ME 545 k - 17 December 2008

M A R I N E D I V I S I O N

G E N E R A L C O N D I T I O N S


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July 2011

RULESFORTHECLASSIFICATIONOFSHIPS

Part DService Notations

Chapters 1 2 3 4 5 4 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Chapter 1 RO-RO CARGO SHIPS

Chapter 2 CONTAINER SHIPS

Chapter 3 LIVESTOCK CARRIERS

Chapter 4 BULK CARRIERS

Chapter 5 ORE CARRIERS

Chapter 6 COMBINATION CARRIERS

Chapter 7 OIL TANKERS AND FLS TANKERS

Chapter 8 CHEMICAL TANKERS

Chapter 9 LIQUEFIED GAS CARRIERS

Chapter 10 TANKERS

Chapter 11 PASSENGER SHIPS

Chapter 12 RO-RO PASSENGER SHIPS

Chapter 13 SHIPS FOR DREDGING ACTIVITY

Chapter 14 TUGS

Chapter 15 SUPPLY VESSELS

Chapter 16 FIRE FIGHTING SHIPS

Chapter 17 OIL RECOVERY SHIPS

Chapter 18 CABLE-LAYING SHIPS

Chapter 19 NON-PROPELLED UNITS

Chapter 20 FISHING VESSELS

Chapter 21 HULL STRUCTURE FOR SHIPS NOT COVERED BY SOLAS
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2 Bureau Veritas July 2011

The English wording of these rules take precedence over editionsin other languages.

Unless otherwise specified, these rules apply to ships for which contracts aresigned after July 1st, 2011. The Society may refer to the contents hereofbefore July 1st, 2011, as and when deemed necessary or appropriate.
http://p/Paper%20to%20be%20used/reference.pdfhttp://p/Paper%20to%20be%20used/reference.pdfhttp://p/Paper%20to%20be%20used/reference.pdf


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July 2011 Bureau Veritas 3

CHAPTER13

SHIPSFORDREDGINGACTIVITY

Section 1 General

1 General 25

1.1 Application1.2 Summary table1.3 Documents to be submitted

Section 2 Hull and Stability

1 Stability 27

1.1 Intact stability1.2 Damage stability where the additional class notation SDS has been requested

2 Structure design principles 29

2.1 General2.2 Longitudinal members in the area of the hopper well2.3 Transverse members in the area of the hopper well2.4 Arrangements relating to suction pipes2.5 Chafing areas2.6 Reinforcements for grounding

2.7 Bolted structures

3 Design loads 32

3.1 General3.2 Loading conditions3.3 Hull girder loads for dredgers, hopper dredgers and hopper units of more than

65 m in length3.4 Hull girder loads for split hopper dredgers and split hopper units of more than

65 m in length3.5 Internal pressures for hopper well in dredging situation

4 Hull girder strength of dredgers, hopper dredgers and hopper units 35

4.1 General4.2 Midship section modulus4.3 Ultimate strength check for ships of more than 65 m in length

5 Hull girder strength of split hopper dredgers and split hopper units 36

5.1 General5.2 Definitions5.3 Hull girder stress5.4 Checking criteria

6 Hull scantlings 37

6.1 General

6.2 Hull girder normal stress for split hopper dredgers and split hopper units of morethan 65 m in length

6.3 Minimum net thicknesses of plating6.4 Bottom plating


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6.5 Ordinary stiffeners6.6 Well bulkhead and cellular keel platings6.7 Transversely framed bottoms

7 Hopper dredgers and hopper units: checking of hopper well structure 39

7.1 General7.2 Floors, webs, trunks, strongbeams and girders

8 Split hopper dredgers and split hopper units: superstructure hinges 40

8.1 General8.2 Arrangements8.3 Materials used for the hinges8.4 Forces8.5 Scantlings of the hinges

9 Split hopper dredgers and split hopper units: decks hinges, hydraulicjack connections and chocks 42

9.1 General9.2 Arrangements9.3 Static forces9.4 Dynamic forces9.5 Scantlings

10 Split hopper dredgers and split hopper units: hydraulic jacks andassociated piping systems 45

10.1 General10.2 Definitions10.3 Arrangements10.4 Scantling of jacks

10.5 Inspection and testing10.6 Relief valve setting

11 Rudders 46

11.1 General11.2 Additional requirements for split hopper dredgers and split hopper units

12 Equipment 46

12.1 General12.2 Additional requirements for split hopper dredgers and split hopper units12.3 Towlines and mooring lines

Section 3 Machinery and Dredging Systems

1 General 49

1.1 Application

2 Dredging system 49

2.1 Attachment of dredging equipment to the hull

3 Steering gear of split hopper dredgers and split hopper units 49

3.1 General3.2 Design of the steering gear

3.3 Synchronisation4 Testing of dredging equipment 49

4.1 On board testing


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Appendix 1 Guidance on calculation of transverse strength hopper well

structure

1 Hopper dredgers and hopper units: checking of hopper well structure 50

1.1 General

2 Floors 50

2.1 General2.2 Different types of bottom and valves used2.3 Load borne by floors2.4 Shear force diagrams2.5 Bending moments for each elementary load2.6 Resultant bending moment2.7 Normal load2.8 Differential opening valves2.9 Buckling of upper flange

3 Strong beams at deck level 543.1 Forces acting on strong beams3.2 Sectional area of strong beams

4 Brackets for trunks 54

4.1 General4.24.3

5 Girders supporting the hydraulic cylinder in the hopper spaces(bottom door types 1, 2 and 3) 55

5.1

5.2


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CHAPTER14

TUGS

Section 1 General

1 General 59

1.1 Application1.2 Summary table


1 General 60

1.1 Application

2 Tugs, salvage tugs and escort tugs 60

2.1 General2.2 Stability2.3 Structure design principles2.4 Hull scantlings2.5 Other structures2.6 Rudder and bulwarks2.7 Equipment2.8 Towing arrangements2.9 Construction and testing

3 Additional requirements for salvage tugs 643.1 General3.2 Equipment

4 Additional requirements for escort tugs 64

4.1 General4.2 Stability4.3 Structural design principles4.4 Equipment4.5 Construction and testing

Section 3 Integrated Tug/Barge Combination1 General 67

1.1 Application1.2 Permanent connections1.3 Removable connections

2 General arrangement design 67

2.1 Bulkhead arrangement

3 Integrated tug/barge combinations with permanent connection:stability, freeboard, design loads, hull scantlings and equipment 68

3.1 Stability calculations3.2 Freeboard calculation3.3 Still water hull girder loads3.4 Wave hull girder loads


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3.5 Still water local loads3.6 Wave local loads3.7 Hull girder strength3.8 Scantlings of plating, ordinary stiffeners and primary supporting members3.9 Equipment

4 Integrated tug/barge combination with removable connection:stability, freeboard, design loads, hull scantlings and equipment 69

4.1 Stability calculations4.2 Freeboard calculation4.3 Still water hull girder loads4.4 Wave hull girder loads4.5 Still water local loads4.6 Wave local loads4.7 Hull girder strength4.8 Scantlings of plating, ordinary stiffeners and primary supporting members4.9 Equipment

5 Connection 70

5.1 General5.2 Scantlings

6 Other structures 70

6.1 Tug fore part6.2 Tug aft part6.3 Barge fore part6.4 Barge aft part

7 Hull outfitting 71

7.1 Rudder and steering gear

8 Construction and testing 71

8.1 Test of the disconnection procedure of removable connection


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CHAPTER15

SUPPLYVESSELS

Section 1 General

1 General 75

1.1 Application1.2 Applicability of additional service features1.3 Definitions1.4 Summary table


1 General 77

1.1 Application1.2 Definitions


2.1 Compartment arrangement for all ships2.2 Compartment arrangement for ships with additional service feature oil product2.3 Compartment arrangement for ships with additional service feature LHNS2.4 Compartment arrangement for ships with additional service feature WS2.5 Access arrangement for all ships2.6 Access arrangement for ships with additional service feature oil product

2.7 Access arrangement for ships with additional service feature LHNS2.8 Access arrangement for ships with additional service feature WS

3 Stability 79

3.1 General3.2 Intact stability for all ships3.3 Intact stability for ships with additional service feature oil product3.4 Damage stability for all ships where the additional class notation SDS has been

requested3.5 Damage stability for ships with additional service feature oil product where the

additional class notation SDS has been requested3.6 Damage stability for ships with additional service feature WS where the

additional class notation SDS has been requested


4.1 General4.2 Side structure exposed to bumping4.3 Deck structure4.4 Structure of cement tanks and mud compartments4.5 Acid spill protection for ships with additional service feature LHNS and WS

5 Design loads 84

5.1 Dry uniform cargoes


6.1 Plating6.2 Ordinary stiffeners6.3 Primary supporting members


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7 Other structure 84

7.1 Aft part7.2 Superstructures and deckhouses7.3 Arrangement for hull and superstructure openings

8 Hull outfitting 858.1 Rudders8.2 Bulwarks8.3 Equipment

Section 3 Machinery and Cargo Systems

1 General 86

1.1 Application1.2 Documents to be submitted

1.3 Definitions2 Machinery systems 86

2.1 Bilge system2.2 Other piping systems not intended for cargo2.3 Cargo heating systems2.4 Exhaust pipes

3 Cargo systems for supply vessels with additional service featuresoil product, LHNS and WS 87

3.1 Cargo segregation3.2 Materials

3.3 Installation of independent portable tanks4 Cargo systems of ships having the additional service feature oil product 87

4.1 Cargo pumping system, piping system and pump rooms4.2 Cargo tanks and cargo storage vessels4.3 Prevention of pollution

5 Cargo systems of ships having the service feature LHNS or WS 88

5.1 General5.2 Cargo pumping and piping systems5.3 Cargo tanks

Section 4 Electrical Installations

1 General 90

1.1 Application1.2 Supply vessels1.3 Supply vessels with additional service feature oil product1.4 Supply vessels with additional service feature LHNS or WS

Section 5 Fire Prevention, Protection and Extinction

1 General 91



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2 Fire prevention and protection 91

2.1 General2.2 Additional requirements for ships having the additional service feature oil

product2.3 Additional requirements for ships having the additional service feature LHNS or

WS

3 Fire fighting 92

3.1 General3.2 Additional requirements for ships having the additional service feature oil

product3.3 Additional requirements for ships having the additional service feature LHNS or

WS


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CHAPTER16

FIREFIGHTINGSHIPS

Section 1 General

1 General 97



1 Stability 981.1 Intact stability


2.1 Hull structure2.2 Water and foam monitors


3.1 Arrangement for hull and superstructure openings

Section 3 Machinery and Systems

1 General 100


2 Design of machinery systems 100

2.1 Manoeuvrability2.2 Fuel oil capacity2.3 Scuppers

3 General requirements for fire-fighting systems 101

3.1 General3.2 Independence of pumping and piping systems3.3 Design and construction of piping systems3.4 Monitors3.5 Monitor control

4 Water fire-fighting system 102

4.1 Characteristics4.2 Monitors4.3 Piping

5 Fixed foam fire-extinguishing system 102

5.1 General5.2 Characteristics5.3 Arrangement


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6 Portable fire-fighting equipment 103

6.1 Portable high expansion foam generator6.2 Hydrants and fire hoses

7 Firemens outfits 103

7.1 Number and characteristics7.2 Compressed air system for breathing apparatuses

8 Testing 104

8.1 General8.2 Workshop tests8.3 On board tests

Section 4 Fire Protection and Extinction

1 General 1051.1 Application1.2 Documents to be submitted

2 Fire protection of exposed surfaces 105

2.1 Structural fire protection2.2 Deadlights and shutters

3 Self-protection water-spraying system 105

3.1 General3.2 Capacity3.3 Arrangement

3.4 Pumps3.5 Piping system and spray nozzles


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CHAPTER17

OILRECOVERYSHIPS

Section 1 General

1 General 109



1 General 1101.1 Oil removal1.2 Definitions


2.1 Segregation of spaces intended for retention of oil2.2 Dangerous spaces2.3 Access to safe spaces

3 Stability 111

3.1 Intact stability

4 Design loads 1114.1 Oil removal and spraying


5.1 Accumulation tanks


6.1 Hull and superstructure openings

7 Construction and testing 111

7.1 Testing


1 General 112

1.1 Documents to be submitted1.2 Definitions

2 Machinery installations and piping systems not intended forrecovered oil 112

2.1 Bilge system

2.2 Sea water cooling system2.3 Water fire-extinguishing system2.4 Exhaust gas systems2.5 Additional requirements for machinery installations in gas-dangerous areas


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3 Pumping system, piping system and pump rooms intended forrecovered oil 113

3.1 Design of pumping and piping systems

3.2 Arrangement of piping systems and pump rooms

4 Settling and accumulation tanks 113

4.1 General

4.2 Vent pipes

4.3 Level gauging and overfilling control

4.4 Heating systems

Section 4 Electrical Installations

1 General 114

1.1 Application

1.2 Documentation to be submitted

2 Design requirements 114

2.1 System of supply

2.2 Earth detection

3 Hazardous locations and types of equipment 114

3.1 Electrical equipment permitted in hazardous areas

Section 5 Fire Protection, Detection and Extinction

1 General 117

1.1 Application

1.2 Documents to be submitted

1.3 Definitions

2 Ventilation systems 117

2.1 General

2.2 Ventilation of recovered oil pump rooms

2.3 Ventilation of enclosed normally entered dangerous spaces other than cargopump rooms

2.4 Ventilation of enclosed safe spaces adjacent to dangerous areas

3 Fire protection and fighting 118

3.1 General

3.2 Oil flashpoint and gas measurement systems

3.3 Structural fire protection

3.4 Fire-fighting


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CHAPTER18

CABLE-LAYINGSHIPS

Section 1 General

1 General 121



1 General 122

1.1 Application

2 Stability 122

2.1 Intact stability2.2 Damage stability for ships where the notation SDS has been required


3.1 Cable tanks3.2 Connection of the machinery and equipment with the hull structure


4.1 Fore part

5 Hull outfitting 123

5.1 Equipment


1 General 124

1.1 Propulsion and manoeuvrability1.2 Documents to be submitted

2 Arrangements for cable laying, hauling and repair 124

2.1 Typical machinery and equipment of cable laying ships2.2 Design of cable handling machinery and equipment2.3 Safety2.4 Testing of cable handling machinery and equipment

3 On board trials 125

3.1 Ship trials3.2 Equipment trials

Section 4 Fire Protection1 Cable tanks 126

1.1 Means for fire fighting


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CHAPTER19

NON-PROPELLEDUNITS

Section 1 General

1 General 129



1 General 130

1.1 Application1.2 Additional class notations for lifting appliances of ships with service notation

pontoon - crane

2 Stability 130

2.1 Intact stability for ships with service notation pontoon or pontoon - crane2.2 Additional intact stability criteria for ships with service notation pontoon - crane


3.1 Hull structure3.2 Lifting appliances

4 Hull girder strength 133

4.1 Yielding check


5.1 General5.2 Hull scantlings of non-propelled units with the service notation pontoon fitted

with arrangements and systems for launching operations5.3 Hull scantlings of non-propelled units with service notation pontoon - crane


6.1 Reinforcement of the flat bottom forward area of ships with one of the service

notations pontoon and pontoon - crane7 Hull outfitting 135

7.1 Equipment

Section 3 Machinery Systems

1 General 137


2 Bilge system 137

2.1 Bilge system in ships having no source of electrical power2.2 Bilge system in ships having a source of electrical power


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CHAPTER20

FISHINGVESSELS

Section 1 General

1 General 141


Section 2 Ship Arrangement


1.1 Subdivision arrangement1.2 Cofferdams


1 Stability 143


2 Hull scantlings of ships equal to or greater than 65 m in length 144

2.1 Plating2.2 Aft ramp

3 Hull scantlings of ships less than 65 m in length 1443.1 General3.2 Permissible stresses3.3 Load point3.4 Design loads3.5 Strength deck sectional area3.6 Plating minimum thickness3.7 Bottom structure3.8 Side structure3.9 Deck structure3.10 Bulkheads

3.11 Connection of the fore part with the structures located aft of the collisionbulkhead3.12 Side shell structure forward of the collision bulkhead and aft of the after peak

bulkhead3.13 Reinforcement of the flat bottom forward area3.14 Reinforcements of the bow flare area3.15 Platforms3.16 Bulbous bow3.17 Stems3.18 Sternframes3.19 Aft ramp3.20 Machinery casings

3.21 Superstructures and deckhouses in steel3.22 Superstructures and deckhouses in aluminium3.23 Hatch covers3.24 Arrangement for hull and superstructure openings


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4 Lifting appliances and fishing devices 163

4.1 General4.2 Design loads4.3 Strength check

5 Hull outfitting 1635.1 Rudder stock scantlings5.2 Propeller shaft brackets5.3 Equipment

6 Protection of hull metallic structures 165

6.1 Protection of deck by wood sheathing6.2 Protection of cargo sides by battens6.3 Deck composition

Section 4 Machinery

1 General 166

1.1 Application1.2 Documents to be submitted1.3 Tests - Trials in ships L 24 m1.4 Tests - Trials in ships L


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6 Air pipes and sounding devices in ships L


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18 Compressed air systems in ships L< 24 m 179

18.118.2 Accessories for compressed air systems18.3 Arrangement of compressed air systems18.4 Construction - Material

19 Exhaust gas systems in ships L 24 m 179

19.1

20 Exhaust gas systems in ships L< 24 m 179

20.1 Hull outlet20.2 Cooling and lagging20.3 Water-cooled exhaust gas pipes

21 Refrigeration systems for the preservation of the catch 180

21.1 General21.2 Design of refrigeration systems

21.3 Arrangement of the refrigerating machinery spaces and refrigerating rooms21.4 Breathing apparatus

22 Propelling and auxiliary machinery in ships L 24 m 180

22.1

23 Propelling and auxiliary machinery in ships L


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4.10 Final sub-circuits

4.11 Electric cables

4.12 Switchboard

4.13 Rotating electrical machines

4.14 Batteries

5 Lightning protection 189

5.1 Application

Section 6 Fire Protection

1 General 190

1.1 Application

1.2 Type approved products

1.3 Definitions2 Water fire-fighting system 191

2.1 General

2.2 Number and type of fire pumps

2.3 Characteristics and arrangement of fire pumps

2.4 Fire main, hydrants and hoses

3 Fire-extinguishing appliances in machinery spaces 193

3.1

3.2

3.3

3.4

4 Fire extinguishers 193

4.1 Design and installation of fire extinguishers

4.2 Arrangement of fire extinguishers in accommodation and service spaces

5 Structural fire protection 194

5.1

5.2 Ships of 45 m in length and over

5.3 Ships of 24 m in length and over but less than 45 m

5.4 Ships of less than 24 m in length

6 Ventilation systems 196

6.1

7 Prevention of fire 197

7.1

8 Means of escape 197

8.1

9 Fire detection 198

9.110 Storage of gas cylinders and dangerous materials 198

10.1


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CHAPTER21

HULLSTRUCTUREFORSHIPS

NOTCOVEREDBYSOLAS

Section 1 Hull Structure

1 Application 201

1.1 General

2 Strength deck sectional area 201

2.1 Strength deck

2.2 Deck sectional area


3.1 General

3.2 Permissible stresses

3.3 Load point

3.4 Design loads

3.5 Plating minimum thicknesses

3.6 Bottom structure

3.7 Side structures

3.8 Deck structures

3.9 Bulkheads

4 Other Structures 211

4.1 Connection of the fore part with the structures located aft of the collisionbulkhead

4.2 Side shell structure forward of the collision bulkhead and aft of the after peakbulkhead

4.3 Reinforcement of the flat bottom forward area

4.4 Reinforcements of the bow flare area

4.5 Platforms

4.6 Bulbous bow

4.7 Stems

4.8 Sternframes

4.9 Aft ramp

4.10 Superstructures and deckhouses in steel

4.11 Superstructures and deckhouses in aluminium

5 Equipment 218

5.1 General

5.2 Equipment for service notations seagoing launch and launch


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Part DService Notations

Chapter 13

SHIPS FOR DREDGING ACTIVITY

SECTION 1 GENERAL

SECTION 2 HULLANDSTABILITY

SECTION 3 MACHINERYANDDREDGINGSYSTEMS

APPENDIX1 GUIDANCEONCALCULATIONOFTRANSVERSESTRENGTH

HOPPERWELLSTRUCTURE


26/222



27/222

Pt D, Ch 13, Sec 1


SECTION 1 GENERAL

1 General

1.1 Application

1.1.1 Ships complying with the requirements of this Chap-ter are eligible for the assignment of one of the followingservice notations:

dredger

hopper dredger

hopper unit

split hopper dredger

split hopper unit

as defined in Pt A, Ch 1, Sec 2, [4.6].

1.1.2 Ships dealt with in this Chapter and which are greaterthan 500 GT are to comply with the requirements of:

Part A, Part B and Part C of the Rules, as applicable,

this Chapter, which is specific to ships for dredgingactivities,

NR216 Materials and Welding.

1.1.3 Ships dealt with in this Chapter and which are lessthan 500 GT are to comply with the requirements of:

Part A and Part D, Chapter 21 of the Rules, as applica-ble,

NR566 Hull Arrangement, Stability and Systems forShips less than 500 GT, as applicable,

this Chapter, which is specific to ships for dredgingactivities,

NR216 Materials and Welding.

1.2 Summary table

1.2.1 Requirements applicable to ships for dredging activi-ties are summarized in Tab 1.

1.3 Documents to be submitted

1.3.1 The document listed in Tab 2 are to be submitted forapproval, as applicable.

1.3.2 The document listed in Tab 3 are to be submitted forinformation, as applicable.

Table 1 : Applicable requirements

Item Greater than 500 GT Less than 500 GT

Ship arrangement Part B NR566

Hull Part B

Ch 13, Sec 2

Part D, Chapter 21

Ch 13, Sec 2

Stability Part B

Ch 13, Sec 2

NR566

Ch 13, Sec 2

Machinery and cargo systems Part C

Ch 13, Sec 3

NR566

Ch 13, Sec 3

Electrical installations Part C NR566

Automation Part C NR566

Fire protection, detection and extinction Part C NR566


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Pt D, Ch 13, Sec 1


Table 2 : Documents to be submitted for approval Table 3 : Documents to be submitted for information

Item n Description of the document

1 Construction of suction inlet tube

2 Gantry foundations

3 Bottom door and cylinder integrations

4 Overflow

5 Calculation of clearances

6 Hinges, chocks and cylinder integrations

7 Integration of spuds

8 Couplings

9 Integration cutter ladder

10 Integration anchor booms

11 Foundation excavator

12 General arrangement of the dredging equipement

13 Specification of the dredging equipement opera-tion test

Item n Description of the document

1 Calculation of SWBM and shear forces in sail ingand working conditions

2 Design loads on all components of the dredgingequipment


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Pt D, Ch 13, Sec 2


SECTION 2 HULLANDSTABILITY

Symbols

For symbols not defined in this Section, refer to the list atthe beginning of this Chapter.

T : Navigation draught, in m, corresponding to theinternational freeboard

TD : Dredging draught, in m, corresponding to the

dredging freeboard

C : Wave parameter defined in Pt B, Ch 5, Sec 2 orPt B, Ch 8, Sec 1, as applicable

H : Wave parameter defined in Pt B, Ch 5, Sec 2k : Material factor for steel, defined in Pt B, Ch 4,

Sec 1, [2.3]

n, n1 : Navigation coefficients, defined in Pt B, Ch 5,

Sec 1, [2.6] or Pt B, Ch 8, Sec 1, [1.4], as appli-cable

nD : Navigation coefficient in dredging situation,

defined in [3.3.3]

s : Spacing, in m, of ordinary stiffeners

: Specific gravity of the mixture of sea water andspoil, taken equal to:

PD : Maximum mass, in t, of the spoil contained in

the hopper space

VD : Volume of the hopper space, in m3, limited to

the highest weir level

g : Gravity acceleration, in m/s2:

g = 9,81 m/s2

l p : Maximum length, in m, of the hopper well

bp : Maximum breadth, in m, of the hopper well

CFA : Combination factor, to be taken equal to:

CFA= 0,7 for load case c

CFA= 1,0 for load case da : Distance from the bottom to the sealing joint

located at the lower part of the hopper well, inm

h1 : Distance, in m, from spoil level to base line

when working at the dredging freeboard (see Fig7)

h2 : Distance, in m, from spoil level to base line

when working at the international freeboard(see Fig 7)

h4 : Distance, in m, from the lowest weir level to

base line

T3 : Navigation draught, in m, with well filled withwater up to waterline

T4 : Navigation draught, in m, with well filled with

water up to the lowest weir level

Ry : Minimum yield stress, in N/mm2, of the mate-

rial, to be taken equal to 235/k N/mm2, unlessotherwise specified

ReH : Minimum yield stress, in N/mm2, of the material

Rm : Minimum ultimate tensile strength, in N/mm2,

of the material.

1 Stability


1.1.1 General

The intact stability of the ship is to be sufficient to complywith the criteria indicated in [1.1.3] for the operationalloading conditions of Pt B, Ch 3, App 2, [1.2.10] and thecalculation method described in [1.1.2].

1.1.2 Calculation method

The calculation of the righting lever curves is to take intoaccount:

the change of trim due to heel the inflow of seawater or outflow of liquid cargo at the

upper edge of the hopper coaming in the case of anopen hopper

the inflow of water at the lower edge of the overflow,located at cargo level or at the lowest possible positionabove cargo level, or at the lower edge of the lowestoverflow ports or spillways.

1.1.3 Intact stability criteria

The area under the righting lever curve is not to be less than0,07 m.rad up to an angle of 15 when the maximum right-

ing lever GZmax occurs at 15 and 0,055 m.

rad up to anangle of 30 when the maximum righting lever GZmaxoccurs at 30 or above. Where the maximum righting leverGZmax occurs at angles of between 15 and 30, the corre-sponding area under the righting lever curve is to be equal

to or greater than A, where A is to be obtained, in m.rad bythe following formula:

A = 0,055 + 0,001 (30 max)

max being the angle of heel in degrees at which the right-ing lever curve reaches its maximum.

The area under the righting lever curve between the anglesof heel of 30 and 40 or between 30 and the down-flood-

ing angle f, if this angle is less than 40, is to be not lessthan 0,03 m.rad.

The righting lever GZ is to be at least 0,20 m at an angle ofheel equal to or greater than 30.

PD

VD------=


30/222

Pt D, Ch 13, Sec 2


The maximum righting lever GZmax should occur at anangle of heel not less than 15.

The initial metacentric height GM0as corrected for the free

surface effect of the tanks and the hopper(s) containing liq-uids is not to be less than 0,15 m.

1.1.4 Weather criterion at the internationalfreeboard

At the international freeboard, the dredger is to comply withthe requirements of Pt B, Ch 3, Sec 2, [3.2] considering:

the state of the cargo as a liquid

10% stores and fuel

and the hopper(s) loaded with a homogeneous cargo upto the upper edge of the hopper coaming if the density

of the cargo is not less than 1000 kg/m3; otherwise thehopper is considered to be partially loaded with a cargo

of density equal to 1000 kg/m3.

1.1.5 Weather criterion at the dredging freeboard

At the dredging freeboard, the dredger is to comply with therequirements of Pt B, Ch 3, Sec 2, [3.2] considering a

reduced wind pressure equal to 270 N/m2 for the mostsevere of the loading conditions in Pt B, Ch 3, App 2,[1.2.10]. The most severe loading condition is defined asthe loading condition where the area under the rightinglever curve between 0 and 40 is the least.

1.1.6 Dredgers with open hopper(s)

When the height of the hopper coaming overflow edgeabove the dredging draught is less than the minimum bowheight as specified in the International Load Line Conven-tion 1966, the loading conditions in Pt B, Ch 3, App 2,[1.2.10] at the dredging draught are to take into account alayer of seawater on top of the cargo up to the overflowedge of the hopper coaming. However, if overflow ports orspillways of a size sufficient to enable a fast freeing of thewater in the hopper on top of the cargo are fitted in the hop-per coaming above the freeboard deck, the layer of seawater may be reduced up to the lower edge of the overflowports or spillways.

The area of the overflow ports or spillways is to be at leastequivalent to the area required by Regulation 24(1) of theInternational Convention on Load Lines, 1966.

1.1.7 Dredgers with bottom doors or similar means

Dredgers with bottom doors or similar means at port sideand at starboard side are to comply with the following crite-ria considering an asymmetric discharging:

the angle of equilibrium is not to exceed 25

the righting lever GZ within the 30 range beyond theangle of equilibrium is to be at least 0,10 m

the range of stability is not to be less than 30.

The dredger is assumed loaded up to the dredging draught

with solid cargo of a density equal to 1900 kg/m3, when dis-charging, 20% of the total hopper load is assumed to be dis-

charged only at one side of the longitudinal centreline ofthe hopper, horizontally equally distributed at the discharg-ing side.

1.2 Damage stability where the additional

class notation SDS has been requested

1.2.1 General

When the dredger is assigned a dredging freeboard which isless than B/2, where B is the statutory freeboard as calcu-lated in accordance with the International Convention onLoad Lines 1966, the dredger is to comply with the require-ments of Pt B, Ch 3, App 3, [1], modified by [1.2.2], [1.2.3]and [1.2.5]. The dredger may not be assigned a freeboardless than B/3.

1.2.2 Calculation method of the righting levercurves

The calculation of the righting lever curves is to take intoaccount:

the change of trim due to heel

the inflow of seawater or outflow of cargo at the upperedge of the hopper coaming in the case of an open hop-per

the inflow of water at the lower edge of the overflow,located at the highest possible position or at the loweredge of the lowest overflow ports or spillways

the sliding of the cargo in the hopper, in transverse and

longitudinal direction, according to the following shift-ing law:

- for 1400 (liquid cargo):

r= g

- for 1400 < < 2000 (sliding cargo):

r= g(2000 ) / 600

- for 2000 (solid cargo):

r= 0

where:

: Cargo density, in kg/m3

r : Angle of heel or angle of trim, in degrees

g : Shifting angle of the cargo, in degrees.

1.2.3 Progressive flooding

Internal and external progressive floodings are to be consid-ered in accordance with the requirements of Pt B, Ch 3, Sec3, [3.3].

1.2.4 The attained subdivision index AU

The attained subdivision index AUis to be calculated for the

draught dUand the corresponding initial trim assuming thedredger in the unloaded condition, i.e. loaded with 50%fuel and stores, no cargo in the hopper(s) and the hopper(s)in direct communication with the sea.


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Pt D, Ch 13, Sec 2


1.2.5 The attained subdivision index AL

The attained subdivision index ALis to be calculated assum-

ing the dredger loaded at the dredging draught dlwith 50%

fuel and stores, for each of the densities dand i defined

by:

the design density d corresponding to the dredging

draught and obtained from the following formula:

d= M2/ V2

where:

M2 : Mass of cargo in the hopper when the

dredger is loaded at the dredging draughtwith 50% fuel and stores

V2 : Volume of the hopper at the highest over-

flow position

each density i greater than d, obtained from the fol-

lowing formula:

i= 2200 200 i

where i is equal to 0; 1; 2; 3; etc.

The damage stability calculations are to be performed tak-ing into account the initial trim of the dredging draught, anassumed permeability of the cargo in the hopper equal to0% and a permeability of the space above the cargo equalto 100%.

1.2.6 Damage stability criteria

The dredger is to comply with the following criteria:

A RAU0,7 R

AL0,7 R

where:

R : Required index as defined in Pt B, Ch 3, App 3,[1.3]

AU : Attained subdivision index at the unloaded

draught dU, as defined in [1.2.4]

AL : Attained subdivision index at the loaded

draught dland for the cargo densities defined in

[1.2.5].

2 Structure design principles

2.1 General

2.1.1 The attention of Designers is drawn to the fact thatstructural arrangement of ships for dredging activitiesinvolves discontinuities and that particular care is to betaken to avoid cracks or fractures.

2.1.2 Where dredgers are likely to work in association withhopper barges, the sheerstrake is to be protected, slightly

below the deck, by a fender efficiently secured to the shellplating and extending over at least two thirds of the shipslength. Compensation is to be provided in way of the gang-way port in raised deck, if fitted.

2.1.3 Where dredgers are likely to work in association withhopper barges, the shell plating is to be protected by afender extending from the load waterline to the lowestwaterline.

Additional structural reinforcements are to be provided in

way of fenders and submitted to the Society for approval.2.1.4 On bucket dredgers, in order to prevent dangerousflooding in the event of damage to the shell plating by metaldebris (e.g. anchors), a watertight compartment is to be pro-vided at the lower part of the caissons on either side of thebucket well in the area of the buckets. The compartment isto be of adequate size to allow surveys to be carried out.

2.1.5 Reinforcements are to be provided at locations wherethe hull is heavily stressed, such as:

beneath the suction pipe gallows

in way of the gallow frame on bucket dredgers

points where tow ropes are secured connections of piles, etc.

2.1.6 The reinforcement of the flat bottom area forward is tocomply with Pt B, Ch 9, Sec 1, [3]considering TFas equal to

the minimum ballast draft forward in heavy weather.

Flat bottom areas, other than flat bottom area forward,where dynamic pressures due to the bottom impact mightoccur are to be examined by the Society on a case by casebasis.

2.1.7 Weirs are to be provided in the hopper spaces. Theirsectional area is to be large enough, taking into account thedensity of the water-spoil mixture to be drained off.

The disposition and location of the weirs are to be suchthat:

they prevent the maximum authorised draught frombeing exceeded during loading

trim and stability are always in accordance with thereviewed loading conditions

draining off is made without any overflowing on thedecks.

2.1.8 The corners of the cut-outs in the bottom plating areto be rounded and the radius is to be as large as possible,

especially near the bottom doors.The shape and the radius of cut-out corners are to be inaccordance with Pt B, Ch 4, Sec 6.

2.1.9 Where hopper barges and suction dredgers areintended for deep sea navigation, it is recommended, as faras possible, that sidescuttles should not be fitted in the shellplating.

2.1.10 The brackets are generally to be of a swept shape. Aflange is to be fitted on the free edge if the length of thisedge exceeds 60 times the web thickness.

2.1.11 For ships with one of the service notations split hop-

per dredgeror split hopper unit, where panting beams areprovided as stated in Pt B, Ch 9, Sec 1, [2.7], stringers andweb frames are to be fitted on the centreline bulkheads ofthe two half-hulls to take up the reactions.


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Pt D, Ch 13, Sec 2


2.2 Longitudinal members in the area of the

hopper well

2.2.1 The scantlings of the midship region are generally to

be kept over the full length of the hopper well.

2.2.2 Attention is to be paid to the structural continuity of

longitudinal members, especially coaming and hopper well

bulkheads.

2.2.3 The upper deck stringer plate is to extend to the lon-

gitudinal bulkhead over the full length of the hopper well.

2.2.4 The fore and aft ends of the longitudinal bulkheads of

the hopper spaces are to be extended by large brackets gen-

erally having a length and a width equal to D/4. It is recom-

mended that a swept shape should be provided for thesebrackets (see Fig 1).

The upper bracket is to be welded to the deck and extended

by a longitudinal deck girder.

The lower bracket, which is generally oblique, is to be

welded to the bottom or to the tank top. In the latter case,

the lower bracket is to be extended inside the double bot-

tom by means of a solid keelson extending at least over

three frame spaces beyond the end of the bracket.

Figure 1 : Brackets at fore and aft ends oflongitudinal bulkheads of the hopper spaces

2.2.5 The fore and aft ends of the centreline cellular keel

are to be extended by means of brackets having a length at

least equal to the depth of this keel.

In areas where a double bottom is provided, the brackets

may be arranged in accordance with Fig 2.

Figure 2 : Brackets at fore and aft ends of cellular keel

2.2.6 The vertical sides of the trunks are to be extendedbeyond the end of the hopper spaces over a distance of atleast 1,5 times their height.

2.2.7 The Society may, on a case-by-case basis, require thatlongitudinal members of the double bottom structure areextended, by means of brackets, inside the side compart-ments bounding the hopper spaces.

2.2.8 Arrangements other than those described in [2.2.4] to[2.2.7] are to be considered by the Society on a case-by-case basis.

2.3 Transverse members in the area of thehopper well

2.3.1 Transverse primary supporting rings

Within the hopper well area, transverse primary supportingrings are to be provided and are to involve:

deep floors inside hopper spaces

side vertical primary supporting members

hopper well vertical primary supporting members

strong beams inside hopper spaces, at deck or trunklevel

where necessary, cross-ties connecting either the side

vertical primary supporting members to the hopper wellvertical primary supporting members or the floor to thehopper well vertical primary supporting members.

The spacing of the transverse rings is generally to be takennot greater than five frame spaces.

2.3.2 The cellular keel is to be rigidly connected to thetransverse rings required in [2.3.1].

2.3.3 The upper part of the cellular keel may be connectedto the deck or trunk structure by means of axial or inclinedpillars in association with strong beams, or by a centrelinewash bulkhead.

2.3.4 The connection of hopper space floors with the longi-tudinal bulkheads and the cellular keel is to be arrangedsuch that the continuity of the strength is ensured.

bracket

hopper space shell

in the same plane

knuckle

inclined bulkhead

strengthening flat

foldin the verticalplane

bracket

knuckle

in the same plane

cellular keel


33/222

Pt D, Ch 13, Sec 2


Where the floor is made of a box with sloping sides, partic-ular attention is to be paid to the continuity of the lowerflange. Fig 3 shows an example of possible connection.

Figure 3 : Example of connection with floor

made of box with sloping sides

2.3.5 The connection between the flanges of the strongbeams and the adjacent structure is generally to be made bymeans of brackets having the thickness of these flanges andextending inside the adjacent structure.

2.4 Arrangements relating to suction pipes

2.4.1 Where a cut-out is necessary in the side shell platingto fit the suction pipe guides, continuity of members is to berestored, for example by means of knuckled plates as thickas the side shell plating and with a knuckle angle as smallas possible.

The knuckles are to be stiffened by reinforced vertical pri-mary supporting members and intercostal girders of thesame web height (see Fig 4 and Fig 5).

Figure 4 : Transversely framed side - Cut-out rein-forced by means of knuckled plate

Figure 5 : Longitudinally framed side - Cut-out rein-forced by means of knuckled plate

The fillet welding between the web of vertical primary sup-porting members and the knuckled plates is not to be madeonto the knuckles, but about 50 mm apart.

2.4.2 The suction pipe guides are to be fitted as far as pos-sible from the hopper space ends or from any cut-out in thebottom or deck plating.

A 60% reinforced deck plate, not exceeding 38 mm, is to beprovided in way of the cut-out of the guides. This plate is toextend over at least one frame space forward and aft of thevertical primary supporting members provided for in[2.4.1].

2.4.3 In areas where, during suction pipe operations, thedrag head and the joint may run against the hull, one orseveral of the following arrangements are generally to beprovided:

thickness plating in excess of thickness obtainedaccording to Pt B, Ch 7, Sec 1 or Pt B, Ch 8, Sec 3, asapplicable, for bilge and side shell

reinforcement of the structure by means of vertical pri-mary supporting members, girders, intermediate framesor longitudinals, depending on the construction type

fenders to be provided outside the hull; these fenderstogether with the bilge shape are not to impede the suc-

tion pipe operation cofferdam to be provided to limit the possible floodingof side compartments.

2.4.4 The suction pipes are generally to be fitted with:

auxiliary devices able to lift the suction pipe, in additionto the suction pipe davits

a sufficient number of attachment points on the suctionpipe itself, to facilitate handling

a load limiting device to avoid any overload, if the suc-tion pipe is equipped with cutting teeth

accessories fitted onto the suction pipe built in severalparts to facilitate partial replacements in case of damage.

2.5 Chafing areas

2.5.1 Some parts of the structure subjected to heavy wear,such as longitudinal bulkheads of hopper spaces, may beprotected or reinforced to avoid frequent replacement.

2.5.2 If protection is provided by means of removableplates, called chafing plates, attention is to be paid to avoidcorrosion between the facing sides of these plates and thehopper space plating.

2.5.3 If reinforcement is made by increasing the thickness,the section moduli may be determined taking into accountthe extra thickness, provided that the chafing limits, beyondwhich the plates are to be replaced, are determined accord-ing to the extra thickness values.

If this extra thickness is disregarded in the section modulicalculation, this is to be clearly indicated on the midshipsection drawing.

2.6 Reinforcements for grounding

2.6.1 If grounding is considered for normal operation of theship, the bottom plating and the bottom structure are to bereinforced as indicated in [2.6.2] to [2.6.5].

2.6.2 Along the full length of the ship, in the area of flatbottoms, the bottom net thickness obtained according to PtB, Ch 7, Sec 1 or Pt B, Ch 8, Sec 3, as applicable, is to beincreased by 2,5 mm.

pillar

longitudinal bulkhead

cellular keel

floor


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Pt D, Ch 13, Sec 2


2.6.3 Where the ship has a transversely framed double bot-tom, floors are to be fitted at each frame space and associ-ated with intercostal longitudinal girders, the mean spacingof which is to be not greater than 2,10 m.

Moreover, intercostal longitudinal ordinary stiffeners

located at mid-spacing of bottom girders are to be provided.

2.6.4 Where the ship has a longitudinally framed doublebottom, the floor spacing may not exceed three framespaces and the bottom girder spacing may not exceed threelongitudinal ordinary stiffener spaces.

intercostal transverse stiffeners are to be provided at mid-span of longitudinal ordinary stiffeners.

Floors are to be stiffened by vertical stiffeners having thesame spacing as the longitudinal ordinary stiffeners.

2.6.5 Where the ship is built with open hopper spaces (bot-tom doors provided on the bottom), reinforcements asrequired in [2.6.3] or [2.6.4] are to be provided within theside compartments, the cellular keel and, in general, withinthe limits of the flat bottom area.

2.7 Bolted structures

2.7.1 Where the dredger is made of several independentmembers connected by bolting, the connection is to beexamined by the Society on a case-by-case basis.

3 Design loads

3.1 General

3.1.1 Design loads are to be determined for the variousload cases in the following two situations:

navigation situation, considering the draught T and thenavigation coefficient n

dredging situation, considering the dredging draught TDand the navigation coefficient nD.

3.1.2 For dredgers made of bolted structure, the Societymay require the hull girder loads calculated with the maxi-mum length of the unit when mounted to be applied toeach individual element.

3.2 Loading conditions

3.2.1 In addition to the requirements in Pt B, Ch 5, Sec 2,[2.1], as applicable, still water loads are to be calculated forthe following loading conditions:

homogeneous loading at maximum dredging draught ifhigher than the maximum service draught

partial loading conditions

any specified non-homogeneous loading condition, in

particular where dredgers are fitted with several hopperspaces

navigation conditions with hopper space(s) filled withwater up to the load line

working conditions at international freeboard with thehopper space(s) filled with spoil

ballast navigation conditions, with empty hopperspace(s), if applicable.

Calculation of the still water bending moment and shear force

for any loading case corresponding to a special use of theship may be required by the Society on a case-by-case basis.In particular, in the case of stationary dredgers, the curve ofthe still water bending moment, where the suction pipe ishorizontal, is to be submitted to the Society for approval.

3.3 Hull girder loads for dredgers, hopper

dredgers and hopper units of more than

65 m in length

3.3.1 Application

The provisions in [3.3.2] to [3.3.5] apply to ships with one

of the service notations dredger, hopper dredgeror hopperunit.

3.3.2 Vertical still water bending moments

In addition to the vertical still water bending momentsMSW,Hand MSW, Sin navigation situation defined in Pt B, Ch

5, Sec 2, [2.2], the vertical still water bending moments indredging situation MSW,H,Dand MSW,S,Dare also to be consid-

ered, in hogging and sagging conditions, respectively.

If the design vertical still water bending moments in dredg-ing situation are not defined at a preliminary design stage,at any hull transverse section, the longitudinal distributionsshown in Pt B, Ch 5, Sec 2, Fig 2 may be considered, where

MSWis the vertical design still water bending moment amid-ships, in dredging hogging or sagging conditions, whoseabsolute values are to be taken not less than the valuesobtained, in kN.m, from the following formulae:

in hogging conditions:

MSWM, H, D= 175 n1C L2B (CB+ 0,7) 103MWV, H, D

in sagging conditions:

MSWM, S, D= 175 n1C L2B (CB+ 0,7) 103+MWV, S, D

where MWV, H, Dand MWV, S, Dare the vertical wave bending

moments in dredging situation, in kN.m, defined in [3.3.3].

3.3.3 Vertical wave bending moments

In addition to the vertical wave bending moments MWV, Hand MWV, Sin navigation situation defined in Pt B, Ch 5, Sec

2, [3.1], the vertical wave bending moments in dredging sit-uation at any hull transverse section are to be obtained, inkN.m, from the following formulae:

in hogging conditions:

MWV, H, D= 190 FMnDC L2B CB103

in sagging conditions:

MWV, S, D= 110 FMnDC L2B (CB+ 0,7) 10

3

where:

FM : Distribution factor defined in Pt B, Ch 5, Sec 2,Tab 1 (see also Pt B, Ch 5, Sec 2, Fig 3)

nD : Coefficient defined in Tab 1 depending on the

operating area, without being taken greater than n.


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Pt D, Ch 13, Sec 2


Table 1 : Coefficient nDin dredging situation

3.3.4 Horizontal wave bending moments

In addition to the horizontal wave bending moment MWHin

navigation situation defined in Pt B, Ch 5, Sec 2, [3.2], thehorizontal wave bending moment in dredging situation atany hull transverse section is to be obtained, in kN.m, fromthe following formula:

MWH, D= 0,42 FMnDH L2TDCB

3.3.5 Vertical wave shear forces

In addition to the vertical wave shear force QW in naviga-

tion situation defined in Pt B, Ch 5, Sec 2, [3.4], the verticalwave shear force in dredging situation at any hull transversesection is to be obtained, in kN, from the following formula:

QW, D= 30 FQnDC L B (CB+ 0,7) 102

where FQis the distribution factor defined in Pt B, Ch 5, Sec

2, Tab 3 (see also Pt B, Ch 5, Sec 2, Fig 6).

3.4 Hull girder loads for split hopper dredg-

ers and split hopper units of more than

65 m in length

3.4.1 Application

The provisions in [3.4.2] to [3.4.8] apply to ships with oneof the service notations split hopper dredgeror split hopperunit.

3.4.2 General

Horizontal bending moments are to be calculated assumingthat the hopper well is simply supported at each end.

The clearance between the two half-hulls is to be largeenough not to be suppressed when the hopper well is fullup.

Details of the calculation of the necessary clearances are tobe submitted to the Society for review.

However, the calculation of the horizontal moments is car-ried out assuming that both ends of the hopper well arepartly clamped, on condition that at deck and bottom levelchocks are provided forward and aft of the well so that:

the clearance between the two half-hulls is nil the chocks are long enough to withstand the end

moments due to the horizontal forces developed alongthe hopper well.

3.4.3 Vertical still water bending moments

The vertical still water bending moments to be applied onone half-hull in navigation and dredging situations are to betaken equal respectively to half the vertical still water bend-ing moments defined in:

Pt B, Ch 5, Sec 2, [2.2] for navigation situation

[3.3.2] for dredging situation.

3.4.4 Vertical wave bending moments

The vertical wave bending moments to be applied on onehalf-hull in navigation and dredging situations are to betaken equal respectively to half the vertical wave bendingmoments defined in:

Pt B, Ch 5, Sec 2, [3.1] for navigation situation

[3.3.3] for dredging situation.

3.4.5 Horizontal still water bending moments

The horizontal still water bending moments to be appliedon one half-hull in navigation and dredging situations are tobe obtained, in kN.m, from the formulae given in Tab 2,assuming that the hopper well is simply supported at eachend.

If the hopper well may not be considered as simply sup-ported at each end, the horizontal still water bendingmoments to be applied on one half-hull in navigation anddredging situations are to be determined on a case by casebasis.

Table 2 : Split hopper dredgers and split hopper unitsHorizontal still water bending moment on half-hulls

Operating area nDAssociated HS, in m

L 110 m 110 m < L 150 m 150 m < L 180 m

dredging within 8 miles from shore 1/3 HS< 1,5 HS< 2,0 HS< 2,0

dredging within 15 miles from shore orwithin 20 miles from port

2/3 1,5 HS< 2,5 2,0 HS< 3,0 2,0 HS< 3,5

dredging over 15 miles from shore 1 HS2,5 HS3,0 HS3,5

Note 1:

HS : Maximum significant wave height, in m, for operating area in dredging situation, according to the operating area nota-tion assigned to the ship (see Pt A, Ch 1, Sec 2, [4.6.3]).

Horizontal still water bending moment MSHH , in kN.m

Hopper well mid-section (1) Hopper well ends (1)

0

(1) Between hopper well mid-section and ends, the valueof the horizontal still water bending moment is to beobtained by linear interpolation.

Note 1:

p : Load per metre, in kN/m, applied along the hop-

per well, defined in Tab 3 depending on theloading condition

c1 : Distance, in m, from deck hinges to ends ofhopper well (see Fig 6).

18---

c12 l p--------+

p l p2
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Pt D, Ch 13, Sec 2


Table 3 : Load per metre applied along the hopper well

Figure 6 : Definitions of dimensions

in hopper well area

Figure 7 : Definitions of distances for calculation

of the load applied along the hopper well

3.4.6 Horizontal wave bending moments

The horizontal wave bending moments to be applied on

one half-hull in navigation and dredging situations are to be

obtained, in kN.m, from the formulae given in Tab 4,

assuming that the hopper well is simply supported at each

end.

If the hopper well may not be considered as simply sup-

ported at each end, the horizontal still water bendingmoments to be applied on one half-hull in navigation and

dredging situations are to be determined on a case by case

basis.

Table 4 : Split hopper dredgers and split hopper units

Horizontal wave bending moment on half-hulls

3.4.7 Combined still water and wave verticalbending moment

In the midship area, the total vertical bending moment MVto be applied on half-hull is to be obtained, in kN.m, from

Tab 5.

At hopper well ends, the total bending moment MVis to be

determined in accordance with Tab 5 considering:

for the still water vertical bending moment: the greaterof the values at the fore and aft hopper well ends

for the vertical wave bending moment: the longitudinaldistribution defined in Pt B, Ch 5, Sec 2, Tab 1.

3.4.8 Combined still water and wave horizontalbending moment

The total horizontal bending moment MHapplied on half-hull at hopper well mid-section and at hopper well ends, innavigation and dredging situations, is to be obtained, inkN.m, from the following formula:

MH= MSHH+ MWHH

where:

MSHH : Horizontal still water bending moment, defined

in [3.4.5] at hopper well mid-section and athopper well ends, in navigation and dredgingsituations

MWHH : Horizontal wave bending moment, defined in[3.4.6] at hopper well mid-section and at hop-per well ends, in navigation and dredging situa-tions.

Loading condition p, in kN/m

Maximum loading atdredging draught

Loading corresponding tointernational freeboard withwell full of spoil

Service condition with wellfilled with water up to thewaterline

0

Service condition with wellfilled with water up to thelowest weir level

h1 a( )2

1 025 TD a( )2

,

2--------------------------------------------------------------------- g

h2 a( )2 1 025 T a( )2,

2------------------------------------------------------------------ g

1 025 h4 a( )2 T4 a( )

2[ ],

2---------------------------------------------------------------------- g

hopper well

p

hinges

C1 C1

D

T

orT

D

h

orh

1

2

a

Horizontal wave bending moment MWHH , in kN.m

Hopper well mid-section (1)

Hopper well

ends (1)

Navigation situation:

0

Dredging situation:

0

(1) Between hopper well mid-section and ends, the valueof the horizontal wave bending moment is to beobtained by linear interpolation.

Note 1:

T : Draught, in m, corresponding to the loadingcondition considered

MWV : Vertical wave bending moment, in kN.m,defined in:

Pt B, Ch 5, Sec 2, [3.1] for the navigationsituation

[3.3.3] for the dredging situation.

T 0 079Cn 2l D

L----- 1

CB 0 7,+( ),+MWV

B------------

T 0 079CnD 2l D

L----- 1

CB 0 7,+( ),+MWV

B------------
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Pt D, Ch 13, Sec 2


Table 5 : Vertical bending moment applied on half-hull

3.5 Internal pressures for hopper well in

dredging situation

3.5.1 Still water pressure for hopper well

The still water pressure to be used in connection with the

inertial pressure in [3.5.2] is to be obtained, in kN/m 2, fromthe following formula:

pS= g 1dD, to be taken not less than 11,0

where:

1 : Coefficient equal to:

1= for < 1,4

1= + (1,4 ) sin2 for 1,4

dD : Vertical distance, in m, from the calculation

point to the highest weir level with the corre-sponding specific gravity of the mixture of seawater and spoil

: Angle, in degrees, between the horizontal planeand the surface of the hull structure to whichthe calculation point belongs.

3.5.2 Inertial pressure for hopper wellThe inertial pressure is to be obtained from Tab 6.

4 Hull girder strength of dredgers,hopper dredgers and hopper units

4.1 General

4.1.1 The hull girder strength of ships with one of the serv-ice notations dredger, hopper dredgeror hopper unitis tobe checked for navigation situation and dredging situationaccording to the criteria of:

Part B, Chapter 6 for ships of more than 65 m in length,considering the still water and wave bending momentsdefined in [3.3]

Pt B, Ch 8, Sec 2, for ships of less than 65 m in length.

Table 6 : Ships for dredging activities

Inertial pressure for hopper well

4.1.2 For dredgers made of bolted structure, the Societymay require the hull girder strength criteria to be applied toeach individual element, considering the loads calculatedaccording to [3.1.2].

4.2 Midship section modulus

4.2.1 In the determination of the midship section modulusaccording to Pt B, Ch 6, Sec 1, [2.3] or Pt B, Ch 8, Sec 2,[1.3], as applicable, account is to be taken of both 85% and100% effectiveness of the sectional area of the cellular keel.

However the 85% and 100% effectiveness of the sectionalarea of the cellular keel may be replaced by the actualeffectiveness of the cellular keel determined by a threedimensional finite element analysis.

4.2.2 Where cut-outs in the side shell are needed to fit thesuction pipe guides, a section modulus calculation not tak-ing account of the side shell plating may be required by theSociety on a case-by-case basis, if the structural continuityis not correctly achieved.

4.3 Ultimate strength check for ships of

more than 65 m in length

4.3.1 In addition to requirements of Pt B, Ch 6, Sec 3, theultimate strength of the hull girder is to be checked, indredging situation, for ships of more than 65 m in lengthwhich comply with the following formula:

where:

ZR,MIN : Minimum gross section modulus, in m3, defined

in Pt B, Ch 6, Sec 2, [4.2.2]

MSW,D : Vertical still water bending moment in dredging

situation, in kN.m, as defined in [3.3.2], in hog-

ging and sagging conditionsMWV,D : Vertical wave bending moment in dredging situ-

ation, in kN.m, as defined in [3.3.3], in hoggingand sagging conditions.

ConditionVertical bending moment MV , in kN.m

Navigation situation Dredging situation

Hogging

Sagging

Note 1:

MSW, H , MSW, S : Still water vertical bending moment in naviga-tion situation in hogging and sagging condition,respectively, defined in Pt B, Ch 5, Sec 2, [2.2]

MWV, H , MWV, S :Wave vertical bending moment in navigationsituation in hogging and sagging condition, respec-tively, defined in Pt B, Ch 5, Sec 2, [3.1]

MSW, H, D , MSW, S, D : Still water vertical bending moment indredging situation, in hogging and sagging con-

dition, respectively, defined in [3.3.2]MWV, H, D , MWV, S, D :Wave vertical bending moment in dredg-

ing situation, in hogging and sagging condition,

respectively, defined in [3.3.3].

MSW H, MWV H,+

2--------------------------------------MSW H D,, MW V H D,,+

2----------------------------------------------

MSW S, MWV S,+

2------------------------------------

MS W S D,, MW V S D,,+

2--------------------------------------------

Ship condition Load case Inertial pressure pW, in kN/m2

Upright

condition

a No inertial pressure

b The greater of:

Inclined

condition

c andd

The greater of:

Note 1:The accelerations aX1, aZ1, aY2and aZ2are to be deter-

mined according to Pt B, Ch 5, Sec 3, [3.4], considering theship in dredging situation, i.e. considering the draught equalto the dredging draught TD.

1 aX12 aZ1

2+ dD

11 0,

CFA 1 aY22 aZ2

2+ dD

11 0,

ZR M IN,MSW D, MWV D,+

175 k--------------------------------------------10 3


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Pt D, Ch 13, Sec 2


5 Hull girder strength of split hopperdredgers and split hopper units

5.1 General

5.1.1 The yielding check of ships with one of the servicenotations split hopper dredgeror split hopper unitand ofmore than 65 m in length is to be carried out for navigationsituation and dredging situation according to [5.2] to [5.4]considering:

each half-hull as being subjected to independent bend-ing

the deck hinges and the hydraulic jacks acting as sup-ports at the ends of the hopper well.

Both the vertical bending moment and horizontal bendingmoment acting within the well area are to be taken intoaccount.

5.1.2 The hull section modulus, considered with the twohalf-hulls connected is to be checked for navigation situa-tion and dredging situation according to the criteria of:

Pt B, Ch 6, Sec 2, [4] for ships of more than 65 m inlength, considering the still water and wave bendingmoments defined in [3.4]

Pt B, Ch 8, Sec 2, [2], for ships of less than 65 m inlength.

See also [4.2] for the determination of the midship sectionmodulus.

5.2 Definitions

5.2.1 Co-ordinate system

The hull girder strength is defined with reference to the fol-lowing co-ordinate system, as shown in Fig 8:

G : Centre of gravity of the transverse section

GY : Transverse axis, parallel to Y defined in Pt B, Ch1, Sec 2, [4] and crossing through G

GZ : Vertical axis, parallel to Z defined in Pt B, Ch 1,Sec 2, [4] and crossing through G

Gy, Gz : Main axes of the transverse section, defined in[5.2.2].

Figure 8 : Half-hull co-ordinate system

5.2.2 Main axes

The main axes Gy and Gz are obtained from the axes GYand GZ by a rotation around the centre of gravity G of anangle obtained from the following formula:

where:

IY : Moment of inertia, in m4, of the transverse sec-

tion around the axis GY

IZ : Moment of inertia, in m4, of the transverse sec-

tion around the axis GZ

IYZ : Inertia product, in m4, of the transverse section,

in the reference (G, GY, GZ).

5.2.3 Bending moments

The bending moments My and Mz in relation to the main

axes Gy and Gz, respectively, are to be obtained, in kN.m,

from the following formulae:My= MVcos + MHsin

Mz= MVsin + MHcos

where:

MV : Vertical bending moment defined in [3.4.7], in

kN.m, to be considered in hogging and saggingconditions, for the navigation and dredging situ-ations

MH : Horizontal bending moment defined in [3.4.8],

in kN.m, to be considered for the navigationand dredging situations

: Angle defined in [5.2.2].As the main inertia axes of each half-hull are oblique, thebending of each half-hull is a deviated bending.

5.3 Hull girder stress

5.3.1 At any point of the transverse section of each half-hull, the hull girder normal stresses are to be obtained, in

N/mm2, from the following formula:

where:

My, Mz : Bending moments, in kN.m, in hogging andsagging conditions, for the navigation anddredging situations, defined in [5.2.3]

IyM, IzM : Moments of inertia, in m4, of the transverse sec-

tion around its main axes

y, z : y and z coordinates, in m, of the calculationpoint with respect to the main axes Gy and Gz.

5.3.2 In the case of partly clamped ends of the hopper well(see [3.4.2]), the hull girder normal stresses are to be calcu-lated in the hopper well mid-section and at hopper wellends.

In this case, the stresses are also to be calculated in the

midship area assuming the ends supported as regards thehorizontal moment. This calculation relates to the begin-ning of the hopper well drainage by opening of the twohalf-hulls.

Z

z

y

YG

1

2---

2I YZ

IZ IY--------------

atan=

1 zMyIyM------- y

MzIzM-------

103

=


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Pt D, Ch 13, Sec 2


5.3.3 In the case of supports at hopper well ends, the cal-culation of the hull girder normal stress is to be carried outin the hopper well mid-section.

5.3.4 For each section of calculation, the most unfavoura-ble combination of moments is to be considered.

5.4 Checking criteria

5.4.1 It is to be checked that the normal stresses calculatedaccording to [5.3.1] are in compliance with the followingformula:

11,ALL

where:

1,ALL : Allowable normal stress, in N/mm2, defined in

Pt B, Ch 6, Sec 2, [3.1.2].

6 Hull scantlings

6.1 General

6.1.1 Hull scantlings are to be checked according to theapplicable requirements of Part B, Chapter 7 or Part B,Chapter 8, as applicable, for the following two situations:

navigation situation, considering the draught T and thenavigation coefficient n

dredging situation, conside

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