MILITARY MOUNTAINEERING FM 3-97.61

8/7/2019 MILITARY MOUNTAINEERING FM 3-97.61

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PREFACE

Mountains exist in almost every country in the world and almost every war has included some type

of mountain operations. This pattern will not change; therefore, soldiers will fight in mountainous

terrain in future conflicts. Although mountain operations have not changed, several advancements in

equipment and transportation have increased the soldiers capabilities. The helicopter now allowsaccess to terrain that was once unreachable or could be reached only by slow methodical climbing.

nclement weather, however, may place various restrictions on the capabilities of air assets available

to a commander. The unit must then possess the necessary mountaineering s!ills to overcome

adverse terrain to reach an ob"ective.

This field manual details techniques soldiers and leaders must !now to cope with mountainous

terrain. These techniques are the foundation upon which the mountaineer must build. They must be

applied to the various situations encountered to include river crossings, glaciers, snow#covered

mountains, ice climbing, roc! climbing, and urban vertical environments. The degree to which this

training is applied must be varied to conform to !nown enemy doctrine, tactics, and actions. This

$M also discusses basic and advanced techniques to include acclimati%ation, illness and in"ury,equipment, anchors, evacuation, movement on glaciers, and training.

This field manual is a training aid for use by qualifiedpersonnel in con"unction with $M '(.),

Mountain *perations, which is used for planning operations in mountainous terrain. +ersonnel

using $M '(.) should attend a recogni%ed -epartment of -efense Mountain arfare /chool for

proper training. Improper use of techniques and procedures by untrained personnel may result

in serious injury or death.+ersonnel should be certified as 0evel , 1asic Mountaineer; 0evel ,

Assault 2limber; or 0evel , Mountain 0eader before using $M '(.) for training 3see Appendix

A4.

The measurements in this manual are stated as they are used in training 3either metric or standard4.

Appendix 1contains a measurement conversion chart for your convenience.

The proponent of this publication is 56 T7A-*2. /ubmit changes for improving this publication

to doctrine8benning.army.mil or on -A $orm 9:9 37ecommended 2hanges to +ublications and

1lan! $orms4 and forward to the 2ommander, AT/5#71*, $ort

1enning, ?A &':@#@@'&.


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should not plan to use them as the only means of movement and resupply. Alternate

methods must be planned due to the variability of weather. nits scheduled for deployment

in mountainous terrain should become self!sufficient and train under various conditions.

Commanders must be familiar with the restraints that the terrain can place on a unit.

!ection I. "#$%TAI% TERRAI%

*perations in the mountains require soldiers to be physically fit and leaders to be experienced in

operations in this terrain. +roblems arise in moving men and transporting loads up and down steep

and varied terrain in order to accomplish the mission. 2hances for success in this environment are

greater when a leader has experience operating under the same conditions as his men.

Acclimati%ation, conditioning, and training are important factors in successful military

mountaineering.

&. 'EFI%ITI#%

Mountains are land forms that rise more than @:: meters above the surrounding plain and are

characteri%ed by steep slopes. /lopes commonly range from to @ degrees. 2liffs and precipices

may be vertical or overhanging. Mountains may consist of an isolated pea!, single ridges, glaciers,

snowfields, compartments, or complex ranges extending for long distances and obstructing

movement. Mountains usually favor the defense; however, attac!s can succeed by using detailed

planning, rehearsals, surprise, and well#led troops.

&(. C#"P#!ITI#%

All mountains are made up of roc!s and all roc!s of minerals 3compounds that cannot be bro!endown except by chemical action4. *f the approximately 9,::: !nown minerals, seven roc!#forming

minerals ma!e up most of the earths crust> quart% and feldspar ma!e up granite and sandstone;

olivene and pyroxene give basalt its dar! color; and amphibole and biotite 3mica4 are the blac!

crystalline spec!s in granitic roc!s. Bxcept for calcite, found in limestone, they all contain silicon

and are often referred to as silicates.

&). R#C* A%' !+#PE T,PE!

-ifferent types of roc! and different slopes present different ha%ards. The following paragraphs

discuss the characteristics and ha%ards of the different roc!s and slopes.

a. -ranite.?ranite produces fewer roc!falls, but "agged edges ma!e pulling rope and

raising equipment more difficult. ?ranite is abrasive and increases the danger of ropes or

accessory cords being cut. 2limbers must beware of large loose boulders. After a rain,

granite dries quic!ly. Most climbing holds are found in crac!s. $ace climbing can be found,

however, it cannot be protected.

b. Chal and +imestone.2hal! and limestone are slippery when wet. 0imestone is usually

solid; however, conglomerate type stones may be loose. 0imestone has poc!ets, face

climbing, and crac!s.


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c. !late and -neiss./late and gneiss can be firm and or brittle in the same area 3red

coloring indicates brittle areas4. 7oc!fall danger is high, and small roc!s may brea! off

when pulled or when pitons are emplaced.

d. !andstone./andstone is usually soft causing handholds and footholds to brea! away

under pressure. 2hoc!s placed in sandstone may or may not hold. /andstone should beallowed to dry for a couple of days after a rain before climbing on itCwet sandstone is

extremely soft. Most climbs follow a crac!. $ace climbing is possible, but any outward pull

will brea! off handholds and footholds, and it is usually difficult to protect.

e. -rassy !lopes.+enetrating roots and increased frost crac!ing cause a continuous

loosening process. ?rassy slopes are slippery after rain, new snow, and dew. After long, dry

spells clumps of the slope tend to brea! away. eight should be distributed evenly; for

example, use flat hand push holds instead of finger pull holds.

f. Firm !prin/ !no0 1Firn !no02./topping a slide on small, leftover snow patches in late

spring can be difficult. 7outes should be planned to avoid these dangers. /elf#arrest shouldbe practiced before encountering this situation. 1eginning climbers should be secured with

rope when climbing on this type surface. 2limbers can glissade down firn snow if necessary.

$irn snow is easier to ascend than wal!ing up scree or talus.

g. Talus.Talus is roc!s that are larger than a dinner plate, but smaller than boulders. They

can be used as stepping#stones to ascend or descend a slope. 5owever, if a talus roc! slips

away it can produce more in"ury than scree because of its si%e.

h. !cree./cree is small roc!s that are from pebble si%e to dinner plate si%e. 7unning down

scree is an effective method of descending in a hurry. *ne can run at full stride without

worryCthe whole scree field is moving with you. 2limbers must beware of larger roc!s that

may be solidly planted under the scree. Ascending scree is a tedious tas!. The scree does not

provide a solid platform and will only slide under foot. f possible, avoid scree when

ascending.

&3. R#C* C+A!!IFICATI#%!

7oc! is classified by origin and mineral composition.

a. I/neous Rocs.-eep within the earths crust and mantle, internal heat, friction and

radioactive decay creates magmas 3melts of silicate minerals4 that solidify into igneousroc!s upon cooling. hen the cooling occurs at depth, under pressure, and over time, the

minerals in the magma crystalli%e slowly and develop well, ma!ing coarse#grained plutonic

roc!. The magma may move upward, propelled by its own lower density, either melting and

combining with the overlying layers or forcing them aside. This results in an intrusive roc!.

f the melt erupts onto the surface it cools rapidly and the minerals form little or no crystal

matrix, creating a volcanic or extrusive roc!.

34Plutonic or Intrusive Rocks./low crystalli%ation from deeply buried magmas

generally means good climbing, since the minerals formed are relatively large and

interwoven into a solid matrix. eathering develops protrusions of resistant

minerals, which ma!es for either a rough#surfaced roc! with excellent friction, or, ifthe resistant crystals are much larger than the surrounding matrix, a surface with

numerous !nobby holds. +ieces of foreign roc! included in the plutonic body while


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it was rising and crystalli%ing, or clusters of segregated minerals, may weather

differently than the main roc! mass and form Dchic!en heads.D

3a4 ntrusions are named according to location and si%e. 0arge 3:: square

!ilometers or larger4 masses of plutonic roc! are called DbatholithsD and small

ones Dstoc!s.D Most plutonic roc! is in the granite family, differing only inthe amounts of constituent minerals contained. A core of such batholiths is in

every ma"or mountain system in the world. n the Alps, /ierras, =orth

2ascades, 7oc!ies, Adirondac!s, and most other ranges this core is at least

partly exposed.

3b4 /mall plutonic intrusions are stoc!s, forced between sedimentary strata,

and di!es, which cut across the strata. Many of these small intrusive bodies

are quic!ly cooled and thus may loo! li!e extrusive roc!.

394 Volcanic or Extrusive Rocks.Bxplosive eruptions e"ect molten roc! so quic!ly

into the air that it hardens into loose aerated masses of fine crystals anduncrystalli%ed glass 3obsidian4. hen this ash consolidates while molten or after

cooling, it is called Dtuff,D a wea! roc! that brea!s down quic!ly and erodes easily.

6uieter eruptions, where widespread lava flows from large fissures, produce basalt.

1asaltic roc!s are fine#grained and often sharp#edged.

3&4Jointing Rocks.n plutonic roc!s, "oints or crac!s are caused by internal stresses

such as contraction during cooling or expansion when overlying roc! erodes or

exfoliates. /ome "oints tend to follow a consistent pattern throughout an entire

mountain and their existence can often be predicted. Therefore, when a ledge

suddenly ends, the "ointCand thus the ledgeCmay begin again around the corner.

hen molten roc! extrudes onto the surface as a lava flow or intrudes into a cold

surrounding mass as a di!e or sill, the contraction from rapid cooling usually causes

so much "ointing that climbing can be extremely ha%ardous. *ccasionally, this

"ointing is regular enough to create massed pillars with usable vertical crac!s such as

-evils Tower in yoming.

b. !edimentary Rocs./edimentary roc!s are born high in the mountains, where erosion

grinds down debris and moves it down to rivers for transportation to its final deposition in

valleys, la!es, or oceans. As sediments accumulate, the bottom layers are solidified by

pressure and by mineral cements precipitated from percolating groundwater. ?ravel and

boulders are transformed into conglomerates; sandy beaches into sandstone; beds of mudinto mudstone or shale; and shell beds and coral reefs into limestone or dolomite.

34 Though in general sedimentary roc!s are much more friable than those cooled

from molten magmas, pressure and cementing often produce solid roc!s. n fact, by

sealing up internal crac!s cementing can result in flawless surfaces, especially in

limestone.

394 Most high mountain ranges have some sedimentary pea!s. Ancient seafloor

limestone can be found on the summits of the 5imalayas and the Alps. The 2anadian

7oc!ies are almost exclusively limestone. ith the exception of the -olomites, in

general sedimentary roc!s do not offer high#angle climbing comparable to that ofgranite.


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c. "etamorphic Rocs.These are igneous or sedimentary roc!s that have been altered

physically and or chemically by the tremendous heat and pressures within the earth. After

sediments are solidified, high heat and pressure can cause their minerals to recrystalli%e. The

bedding planes 3strata4 may also be distorted by folding and squee%ing. /hale changes to

slate or schist, sandstone and conglomerate into quart%ite, and limestone to marble. These

changes may be minimal, only slightly altering the sediments, or extensive enough toproduce gneiss, which is almost indistinguishable from igneous roc!.

34 Metamorphic roc!s may have not only "oints and bedding, but cleavage or

foliation, a series of thinly spaced crac!s caused by the pressures of folding. 1ecause

of this cleavage, lower grades of metamorphic roc!s may be completely unsuitable

for climbing because the roc! is too rotten for safe movement.

394 5igher degrees of metamorphism or metamorphism of the right roc!s provide a

solid climbing surface. The /hawangun!s of =ew Eor! are an excellent example of

high#grade conglomerate quart%ite, which offers world class climbing. The center of

the ?reen Mountain anticline contains heavily metamorphosed schist, which alsoprovides solid climbing.

&4. "#$%TAI% 5$I+'I%-

The two primary mechanisms for mountain#building are volcanic and tectonic activity. Folcanoes

are constructed from lava and ash, which begin within the earth as magma. Tectonic activity causes

plates to collide, heaving up fold mountains, and to pull apart and crac!, forming fault#bloc!

mountain ranges.

a. Plate Tectonics.The massive slabs composing the outer layer are called tectonic plates.

These plates are made up of portions of lighter, granitic continental crust, and heavier,

basaltic oceanic crust attached to slabs of the rigid upper mantle. $loating slowly over the

more malleable asthenosphere, their movement relative to each other creates earthqua!es,

volcanoes, ocean trenches, and mountain ridge systems.

b. "ountain !tructure.The different hori%ontal and vertical stresses that create mountains

usually produce complex patterns. Bach type of stress produces a typical structure, and most

mountains can be described in terms of these structures.

34Dome Mountains.A simple upward bulge of the crust forms dome mountains

such as the *%ar!s of Ar!ansas and Missouri, =ew Eor!s Adirondac!s, the*lympics of ashington, and the 5igh


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3b4 /ometimes a bloc! is faulted on both sides and rises or falls as a unit.

More often, however, it is faulted on one side only. The Tetons of yoming

and the /ierra =evada display thisCalong the single %one of faults the range

throws up impressive steep scarps, while on the other side the bloc! bends

but does not brea!, leaving a gentler slope from the base of the range to the

crest. An example of a dropped bloc! is 2alifornias -eath Falley, which isbelow sea level and could not have been carved by erosion.

3&4 Fold Mountains.Tectonic forces, in which continental plates collide or ride over

each other, have given rise to the most common mountain formCfold mountains.

?eologists call folds geosynclines.


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&6. R#$TE C+A!!IFICATI#%

Military mountaineers must be able to assess a vertical obstacle, develop a course of action to

overcome the obstacle, and have the s!ills to accomplish the plan. Assessment of a vertical obstacle

requires experience in the classifications of routes and understanding the levels of difficulty they

represent. ithout a solid understanding of the difficulty of a chosen route, the mountain leader canplace his life and the life of other soldiers in extreme danger. gnorance is the most dangerous

ha%ard in the mountain environment.

a. n =orth America the Eosemite -ecimal /ystem 3E-/4 is used to rate the difficulty of

routes in mountainous terrain. The E-/ classes are>

2lass C5i!ing trail.

2lass 9C*ff#trail scramble.

2lass &C2limbing, use of ropes for beginners 3moderate scrambling4.

2lass C1elayed climbing. 3This is moderate to difficult scrambling, which may

have some exposure.4 2lass @C$ree climbing. 3This class requires climbers to be roped up, belay and

emplace intermediate protection.4

b. 2lass @ is further subdivided into the following classifications>

34 2lass @.:#@.C0ittle difficulty. This is the simplest form of free climbing. 5ands

are necessary to support balance. This is sometimes referred to as advanced roc!

scrambling.

394 2lass @.@CModerate difficulty. Three points of contact are necessary.

3&4 2lass @.)CMedium difficulty. The climber can experience vertical position or

overhangs where good grips can require moderate levels of energy expenditure.

34 2lass @.(C?reat difficulty. 2onsiderable climbing experience is necessary.

0onger stretches of climbing requiring several points of intermediate protection.

5igher levels of energy expenditure will be experienced.

3@4 2lass @.CFery great difficulty. ncreasing amount of intermediate protection is

the rule. 5igh physical conditioning, climbing technique, and experience required.

3)4 2lass @.'CBxtremely great difficulty. 7equires well above average ability and

excellent condition. Bxposed positions, often combined with small belay points.

+assages of the difficult sections can often be accomplished under good conditions.

*ften combined with aid climbing 3A:#A4.

3(4 2lass @.:CBxtraordinary difficulty. 2limb only with improved equipment and

intense training. 1esides acrobatic climbing technique, mastery of refined security

technique is indispensable. *ften combined with aid climbing 3A:#A4.

34 2lass @.#@.C?reater increases of difficulty, requiring more climbing ability,

experience, and energy expenditure. *nly talented and dedicated climbers reach thislevel.


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3(4 A)CBxtremely severe aid. 2ontinuous A@ climbing with A@ belay stations. f

the leader falls, the whole rope team will probably experience ground fall.

34 Aid climbing classes are also further divided into IJ# categories, such as A&I or

A, which would simply refer to easy or hard.

e. ?rade ratings 3commitment grades4 inform the climber of the approximate time a climber

trained to the level of the climb will ta!e to complete the route.

C/everal hours.

C5alf of a day.

CAbout three#fourths of a day.

FC0ong hard day 3usually not less than @.(4.

FC J9 to 9 J9 days 3usually not less than @.4.

FC?reater than 9 days.

f. 2limbing difficulties are rated by different systems. Table #shows a comparison ofthese systems.

E-/ 3Eosemite -ecimal /ystem4C


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@.& F very difficult &b, c, a

(

@. FI hard very difficult &b, c, a , '

@.@ F# mild severe &b, c, a sup :,

@.) F severe, hard severe,

a

a, b, c 9, &

@.( FI severe, hard severe,

b

a, b, c sup

@. F# hard severe, hard

very severe, c

@a, b F @

@.' F @a @b, c Fsup ), (

@.:a F# B, @b @b, c F

@.:b F B, @b @b, c Fsup '

@.:c F B, @b @b, c F 9:

@.:d FI BJB9, @b#@c @b, c Fsup 9

@.a F# B&, )a )a, b, c F 99

@.b F B&JB, )a )a, b, c F 9&

@.c F B, )b )a, b, c Fsup 9

@.9a K# B@, B)J(, )c (a F 9)

@.9b K B@, B)J(, )c (a Fsup 9(


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@.9c K B@, B)J(, )c (a

9

@.9d KI B)J(, (a (a

9'

Table &. Ratin/ systems.

g. ce climbing ratings can have commitment ratings and technical ratings. The numerical

ratings are often prefaced with 3waterfall ice4, A 3alpine ice4, or M 3mixed roc! and

ice4.

34 Commitment Ratings. 2ommitment ratings are expressed in 7oman numerals.

CA short, easy climb near the road, with no avalanche ha%ard and a

straightforward descent.

CA route of one or two pitches within a short distance of rescue assistance,

with little ob"ective ha%ard.

CA multipitch route at low elevation, or a one#pitch climb with an

approach that ta!es about an hour. The route requires anywhere from a few

hours to a long day to complete. The descent may require building rappel

anchors, and the route might be prone to avalanche.

FCA multipitch route at higher elevations; may require several hours of

approach on s!is or foot. This route is sub"ect to ob"ective ha%ards, possibly

with a ha%ardous descent.

FCA long climb in a remote setting, requiring all day to complete the climbitself. 7equires many rappels off anchors for the descent. This route has

sustained exposure to avalanche or other ob"ective ha%ards.

FCA long ice climb in an alpine setting, with sustained technical climbing.

*nly elite climbers will complete it in a day. A difficult and involved

approach and descent, with ob"ective ha%ards ever#present, all in a remote

area.

FCBverything a grade F has, and more of it. +ossibly days to approach

the climb, and ob"ective ha%ards rendering survival as questionable. -ifficult

physically and mentally.

394 !ec"nical Ratings.Technical ratings are expressed as Arabic numerals.

CA fro%en la!e or stream bed.

9CA pitch with short sections of ice up to : degrees; lots of opportunity for

protection and good anchors.

&C/ustained ice up to : degrees; the ice is usually good, with places to rest,

but it requires s!ill at placing protection and setting anchors.

CA sustained pitch that is vertical or slightly less than vertical; may have

special features such as chandeliers and run#outs between protection.

@CA long, strenuous pitch, possibly @: meters of @# to ':#degree ice with

few if any rests between anchors. The pitch may be shorter, but on featureless

ice. ?ood s!ills at placing protection are required.


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)CA full @:#meter pitch of dead vertical ice, possibly of poor quality;

requires efficiency of movement and ability to place protection while in

aw!ward stances.

(CA full rope length of thin vertical or overhanging ice of dubious adhesion.

An extremely tough pitch, physically and mentally, requiring agility and

creativity. C/imply the hardest ice climbing ever done; extremely bold and

gymnastic.

&8. CR#!!&C#$%TR, "#9E"E%T

/oldiers must !now the terrain to determine the feasible routes for cross#country movement when

no roads or trails are available.

a. A pre#operations intelligence effort should include topographic and photographic map

coverage as well as detailed weather data for the area of operations. hen planning

mountain operations, additional information may be needed about si%e, location, andcharacteristics of landforms; drainage; types of roc! and soil; and the density and

distribution of vegetation. 2ontrol must be decentrali%ed to lower levels because of varied

terrain, erratic weather, and communication problems inherent to mountainous regions.

b. Movement is often restricted due to terrain and weather. The erratic weather requires that

soldiers be prepared for wide variations in temperature, types, and amounts of precipitation.

34 Movement above the timberline reduces the amount of protective cover available

at lower elevations. The logistical problem is important; therefore, each man must be

self#sufficient to cope with normal weather changes using materials from his

ruc!sac!.

394 Movement during a storm is difficult due to poor visibility and bad footing on

steep terrain. Although the temperature is often higher during a storm than during

clear weather, the dampness of rain and snow and the penetration of wind cause

soldiers to chill quic!ly. Although climbers should get off the high ground and see!

shelter and warmth, if possible, during severe mountain storms, capable commanders

may use reduced visibility to achieve tactical surprise.

c. hen the tactical situation requires continued movement during a storm, the following

precautions should be observed>

Maintain visual contact.

Geep warm. Maintain energy and body heat by eating and drin!ing often; carry food

that can be eaten quic!ly and while on the move.

Geep dry. ear wet#weather clothing when appropriate, but do not overdress, which

can cause excessive perspiration and dampen clothing. As soon as the ob"ective is

reached and shelter secured, put on dry clothing.

-o not rush. 5asty movement during storms leads to brea!s in contact and accidents.

f lost, stay warm, dry, and calm.

-o not use ravines as routes of approach during a storm as they often fill with water

and are prone to flash floods. Avoid high pinnacles and ridgelines during electrical storms.

Avoid areas of potential avalanche or roc!#fall danger.


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&:. C#9ER A%' C#%CEA+"E%T

hen moving in the mountains, outcroppings, boulders, heavy vegetation, and intermediate terrain

can provide cover and concealment. -igging fighting positions and temporary fortifications is

difficult because soil is often thin or stony. The selection of dug#in positions requires detailed

planning. /ome roc! types, such as volcanic tuff, are easily excavated. n other areas, boulders andother loose roc!s can be used for building hasty fortifications. n alpine environments, snow and ice

bloc!s may be cut and stac!ed to supplement dug#in positions. As in all operations, positions and

routes must be camouflaged to blend in with the surrounding terrain to prevent aerial detection.

&;. #5!ER9ATI#%

*bservation in mountains varies because of weather and ground cover. The dominating height of

mountainous terrain permits excellent long#range observation. 5owever, rapidly changing weather

with frequent periods of high winds, rain, snow, sleet, hail, and fog can limit visibility. The rugged

nature of the terrain often produces dead space at midranges.

a. 0ow cloud cover at higher elevations may neutrali%e the effectiveness of *+s established

on pea!s or mountaintops. 5igh wind speeds and sound often mas! the noises of troop

movement. /everal *+s may need to be established laterally, in depth, and at varying

altitudes to provide visual coverage of the battle area.

b. 2onversely, the nature of the terrain can be used to provide concealment from

observation. This concealment can be obtained in the dead space. Mountainous regions are

sub"ect to intense shadowing effects when the sun is low in relatively clear s!ies. The

contrast from lighted to shaded areas causes visual acuity in the shaded regions to be

considerably reduced. These shadowed areas can provide increased concealment when

combined with other camouflage and should be considered in maneuver plans.

&


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Mountain weather can be either a dangerous obstacle to operations or a valuable aid, depending on

how well it is understood and to what extent advantage is ta!en of its peculiar characteristics.

a. eather often determines the success or failure of a mission since it is highly changeable.

Military operations plans must be flexible, especially in planning airmobile and airborne

operations. The weather must be anticipated to allow enough time for planning so that theleaders of subordinate units can use their initiative in turning an important weather factor in

their favor. The clouds that often cover the tops of mountains and the fogs that cover valleys

are an excellent means of concealing movements that normally are made during dar!ness or

in smo!e. 0imited visibility can be used as a combat multiplier.

b. The safety or danger of almost all high mountain regions, especially in winter, depends

upon a change of a few degrees of temperature above or below the free%ing point. Base and

speed of travel depend mainly on the weather. Terrain that can be crossed swiftly and safely

one day may become impassable or highly dangerous the next due to snowfall, rainfall, or a

rise in temperature. The reverse can happen "ust as quic!ly. The prevalence of avalanches

depends on terrain, snow conditions, and weather factors.

c. /ome mountains, such as those found in desert regions, are dry and barren with

temperatures ranging from extreme heat in the summer to extreme cold in the winter. n

tropical regions, lush "ungles with heavy seasonal rains and little temperature variation often

cover mountains. 5igh roc!y crags with glaciated pea!s can be found in mountain ranges at

most latitudes along the western portion of the Americas and Asia.

d. /evere weather may decrease morale and increase basic survival problems. These

problems can be minimi%ed when men have been trained to accept the weather by being

self#sufficient. Mountain soldiers properly equipped and trained can use the weather to their

advantage in combat operations.

&(. "#$%TAI% AIR

5igh mountain air is dry and may be drier in the winter. 2old air has a reduced capacity to hold

water vapor. 1ecause of this increased dryness, equipment does not rust as quic!ly and organic

material decomposes slowly. The dry air also requires soldiers to increase consumption of water.

The reduced water vapor in the air causes an increase in evaporation of moisture from the s!in and

in loss of water through transpiration in the respiratory system. -ue to the cold, most soldiers do not

naturally consume the quantity of fluids they would at higher temperatures and must be encouraged

to consciously increase their fluid inta!e.

a. +ressure is low in mountainous areas due to the altitude. The barometer usually drops 9.@

centimeters for every &:: meters gained in elevation 3& percent4.

b. The air at higher altitudes is thinner as atmospheric pressure drops with the increasing

altitude. The altitude has a natural filtering effect on the suns rays. 7ays are absorbed or

reflected in part by the molecular content of the atmosphere. This effect is greater at lower

altitudes. At higher altitudes, the thinner, drier air has a reduced molecular content and,

consequently, a reduced filtering effect on the suns rays. The intensity of both visible and

ultraviolet rays is greater with increased altitude. These conditions increase the chance of

sunburn, especially when combined with a snow cover that reflects the rays upward.

&). =EATHER CHARACTERI!TIC!


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The earth is surrounded by an atmosphere that is divided into several layers. The worlds weather

systems are in the lower of these layers !nown as the Dtroposphere.D This layer reaches as high as

:,::: feet. eather is a result of an atmosphere, oceans, land masses, unequal heating and cooling

from the sun, and the earths rotation. The weather found in any one place depends on many things

such as the air temperature, humidity 3moisture content4, air pressure 3barometric pressure4, how it

is being moved, and if it is being lifted or not.

a. Air pressure is the DweightD of the atmosphere at any given place. The higher the pressure,

the better the weather will be. ith lower air pressure, the weather will more than li!ely be

worse. n order to understand this, imagine that the air in the atmosphere acts li!e a liquid.

Areas with a high level of this DliquidD exert more pressure on an area and are called high#

pressure areas. Areas with a lower level are called low#pressure areas. The average air

pressure at sea level is 9'.'9 inches of mercury 3hg4 or ,:& millibars 3mb4. The higher in

altitude, the lower the pressure.

34#ig" Pressure.The characteristics of a high#pressure area are as follows>

The airflow is cloc!wise and out.

*therwise !nown as an DanticycloneD.

Associated with clear s!ies.

?enerally the winds will be mild.

-epicted as a blue D5D on weather maps.

394$o% Pressure. The characteristics of a low#pressure area are as follows>

The airflow is countercloc!wise and in.

*therwise !nown as a DcycloneD.

Associated with bad weather.

-epicted as a red D0D on weather maps.

b. Air from a high#pressure area is basically trying to flow out and equali%e its pressure with

the surrounding air. 0ow pressure, on the other hand, is building up vertically by pulling air

in from outside itself, which causes atmospheric instability resulting in bad weather.

c. *n a weather map, these differences in pressure are depicted as isobars. sobars resemble

contour lines and are measured in either millibars or inches of mercury. The areas of high

pressure are called DridgesD and lows are called Dtroughs.D

&3. =I%'

n high mountains, the ridges and passes are seldom calm; however, strong winds in protected

valleys are rare. =ormally, wind speed increases with altitude since the earths frictional drag is

strongest near the ground. This effect is intensified by mountainous terrain. inds are accelerated

when they converge through mountain passes and canyons. 1ecause of these funneling effects, the

wind may blast with great force on an exposed mountainside or summit.


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more, soldiers should lay on the ground during gusts and continue moving during lulls. f a

hurricane# force wind blows where there is sand or snow, dense clouds fill the air. The roc!y

debris or chun!s of snow crust are hurled near the surface. -uring the winter season, or at

high altitudes, commanders must be constantly aware of the wind#chill factor and associated

cold#weather in"uries 3see 2hapter 94.

b. inds are formed due to the uneven heating of the air by the sun and rotation of the earth.

Much of the worlds weather depends on a system of winds that blow in a set direction.

c. Above hot surfaces, air expands and moves to colder areas where it cools and becomes

denser, and sin!s to the earths surface. The results are a circulation of air from the poles

along the surface of the earth to the equator, where it rises and moves to the poles again.

d. 5eating and cooling together with the rotation of the earth causes surface winds. n the

=orthern 5emisphere, there are three prevailing winds>

34Polar Easterlies. These are winds from the polar region moving from the east.This is air that has cooled and settled at the poles.

394Prevailing &esterlies. These winds originate from approximately &: degrees

north latitude from the west. This is an area where prematurely cooled air, due to the

earths rotation, has settled to the surface.

3&4'ort"east !rade%inds. These are winds that originate from approximately &:o

north from the northeast.

e. The "et stream is a long meandering current of high#speed winds often exceeding 9@:

miles per hour near the transition %one between the troposphere and the stratosphere !nown

as the tropopause. These winds blow from a generally westerly direction dipping down and

pic!ing up air masses from the tropical regions and going north and bringing down air

masses from the polar regions.

f. The patterns of wind mentioned above move air. This air comes in parcels called Dair

masses.D These air masses can vary from the si%e of a small town to as large as a country.

These air masses are named from where they originate>

MaritimeCover water.

2ontinentalCover land +olarCnorth of ):onorth latitude.

TropicalCsouth of ):onorth latitude.

2ombining these parcels of air provides the names and description of the four types of air

masses>

2ontinental +olarCcold, dry air mass.

Maritime +olarCcold, wet air mass.

Maritime TropicalCwarm, wet air mass.

2ontinental TropicalCwarm, dry air mass.

g. Two types of winds are peculiar to mountain environments, but do not necessarily affect

the weather.
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34(na)atic &ind *Valle+ &inds,.These winds blow up mountain valleys to replace

warm rising air and are usually light winds.

394ata)atic &ind *Mountain &ind,.These winds blow down mountain valley

slopes caused by the cooling of air and are occasionally strong winds.

&4. H$"I'IT,

5umidity is the amount of moisture in the air. All air holds water vapor even if it cannot be seen.

Air can hold only so much water vapor; however, the warmer the air, the more moisture it can hold.

hen air can hold all that it can the air is DsaturatedD or has :: percent relative humidity.

a. f air is cooled beyond its saturation point, the air will release its moisture in one form or

another 3clouds, fog, dew, rain, snow, and so on4. The temperature at which this happens is

called the Dcondensation pointD. The condensation point varies depending on the amount of

water vapor contained in the air and the temperature of the air. f the air contains a great deal

of water, condensation can occur at a temperature of ) degrees $ahrenheit, but if the air isdry and does not hold much moisture, condensation may not form until the temperature

drops to &9 degrees $ahrenheit or even below free%ing.

b. The adiabatic lapse rate is the rate at which air cools as it rises or warms as it descends.

This rate varies depending on the moisture content of the air. /aturated 3moist4 air will warm

and cool approximately &.9 degrees $ahrenheit per ,::: feet of elevation gained or lost.

-ry air will warm and cool approximately @.@ degrees $ahrenheit per ,::: feet of elevation

gained or lost.

&6. C+#$' F#R"ATI#%

2louds are indicators of weather conditions. 1y reading cloud shapes and patterns, observers can

forecast weather with little need for additional equipment such as a barometer, wind meter, and

thermometer. Any time air is lifted or cooled beyond its saturation point 3:: percent relative

humidity4, clouds are formed. The four ways air gets lifted and cooled beyond its saturation point

are as follows.

a. Con>ecti>e +iftin/.This effect happens due to the suns heat radiating off the Barths

surface causing air currents 3thermals4 to rise straight up and lift air to a point of saturation.

b. Frontal +iftin/.A front is formed when two air masses of different moisture content andtemperature collide. /ince air masses will not mix, warmer air is forced aloft over the colder

air mass. $rom there it is cooled and then reaches its saturation point. $rontal lifting creates

the ma"ority of precipitation.

c. Cyclonic +iftin/.An area of low pressure pulls air into its center from all over in a

countercloc!wise direction. *nce this air reaches the center of the low pressure, it has

nowhere to go but up. Air continues to lift until it reaches the saturation point.

d. #ro/raphic +iftin/.This happens when an air mass is pushed up and over a mass of

higher ground such as a mountain. Air is cooled due to the adiabatic lapse rate until the airs

saturation point is reached.

&8. T,PE! #F C+#$'!


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2louds are one of the signposts to what is happening with the weather. 2louds can be described in

many ways. They can be classified by height or appearance, or even by the amount of area covered

vertically or hori%ontally. 2louds are classified into five categories> low#, mid#, and high#level

clouds; vertically#developed clouds; and less common clouds.

a. +o0&+e>el Clouds. 0ow#level clouds 3: to ),@:: feet4 are either cumulus or stratus3$igures #and #94. 0ow#level clouds are mostly composed of water droplets since their

bases lie below ),@:: feet. hen temperatures are cold enough, these clouds may also

contain ice particles and snow.

Fi/ure &. Cumulus clouds.

Fi/ure &(. !tratus clouds.

34 The two types of precipitating low#level clouds are nimbostratus and

stratocumulus 3$igures #&and #4.
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Fi/ure &). %imbostratus clouds.

Fi/ure &3. !tratocumulus clouds.

3a4 =imbostratus clouds are dar!, low#level clouds accompanied by light to

moderately falling precipitation. The sun or moon is not visible through

nimbostratus clouds, which distinguishes them from mid#level altostratus

clouds. 1ecause of the fog and falling precipitation commonly found beneath

and around nimbostratus clouds, the cloud base is typically extremely diffuse

and difficult to accurately determine.

3b4 /tratocumulus clouds generally appear as a low, lumpy layer of clouds

that is sometimes accompanied by wea! precipitation. /tratocumulus vary in

color from dar! gray to light gray and may appear as rounded masses with

brea!s of clear s!y in between. 1ecause the individual elements of

stratocumulus are larger than those of altocumulus, deciphering between the

two cloud types is easier. ith your arm extended toward the s!y,

altocumulus elements are about the si%e of a thumbnail while stratocumulus

are about the si%e of a fist.

394 0ow#level clouds may be identified by their height above nearby surrounding

relief of !nown elevation. Most precipitation originates from low#level clouds

because rain or snow usually evaporate before reaching the ground from higher

clouds. 0ow#level clouds usually indicate impending precipitation, especially if the

cloud is more than &,::: feet thic!. 32louds that appear dar! at their bases are morethan &,::: feet thic!.4

b. "id&+e>el Clouds. Mid#level clouds 3between ),@:: to 9:,::: feet4 have a prefix of alto.

Middle clouds appear less distinct than low clouds because of their height. Alto clouds with

sharp edges are warmer because they are composed mainly of water droplets. 2old clouds,

composed mainly of ice crystals and usually colder than #&: degrees $, have distinct edges

that grade gradually into the surrounding s!y. Middle clouds usually indicate fair weather,

especially if they are rising over time. 0owering middle clouds indicate potential storms,

though usually hours away. There are two types of mid#level clouds, altocumulus and

altostratus clouds 3$igures #@and #)4.
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Fi/ure &4. Altocumulus.

Fi/ure &6. Altostratus.

34 Altocumulus clouds can appear as parallel bands or rounded masses. Typically a

portion of an altocumulus cloud is shaded, a characteristic which ma!es them

distinguishable from high#level cirrocumulus. Altocumulus clouds usually form in

advance of a cold front. The presence of altocumulus clouds on a warm humid

summer morning is commonly followed by thunderstorms later in the day.

Altocumulus clouds that are scattered rather than even, in a blue s!y, are called Dfair

weatherD cumulus and suggest arrival of high pressure and clear s!ies.

394 Altostratus clouds are often confused with cirrostratus. The one distinguishing

feature is that a halo is not observed around the sun or moon. ith altostratus, the

sun or moon is only vaguely visible and appears as if it were shining through frosted

glass.

c. Hi/h&+e>el Clouds. 5igh#level clouds 3more than 9:,::: feet above ground level4 are

usually fro%en clouds, indicating air temperatures at that elevation below #&: degrees

$ahrenheit, with a fibrous structure and blurred outlines. The s!y is often covered with a

thin veil of cirrus that partly obscures the sun or, at night, produces a ring of light around the

moon. The arrival of cirrus indicates moisture aloft and the approach of a traveling storm

system. +recipitation is often 9 to &) hours away. As the storm approaches, the cirrus

thic!ens and lowers, becoming altostratus and eventually stratus. Temperatures are warm,

humidity rises, and winds become southerly or south easterly. The two types of high#levelclouds are cirrus and cirrostratus 3$igure #(and $igure #4.
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Fi/ure &8. Cirrus.

Fi/ure &:. Cirrostratus.

34 2irrus clouds are the most common of the high#level clouds. Typically found ataltitudes greater than 9:,::: feet, cirrus are composed of ice crystals that form when

super#cooled water droplets free%e. 2irrus clouds generally occur in fair weather and

point in the direction of air movement at their elevation. 2irrus can be observed in a

variety of shapes and si%es. They can be nearly straight, shaped li!e a comma, or

seemingly all tangled together. Bxtensive cirrus clouds are associated with an

approaching warm front.

394 2irrostratus clouds are sheet#li!e, high#level clouds composed of ice crystals.

They are relatively transparent and can cover the entire s!y and be up to several

thousand feet thic!. The sun or moon can be seen through cirrostratus. /ometimes

the only indication of cirrostratus clouds is a halo around the sun or moon.2irrostratus clouds tend to thic!en as a warm front approaches, signifying an

increased production of ice crystals. As a result, the halo gradually disappears and

the sun or moon becomes less visible.

d. 9ertical&'e>elopment Clouds.2louds with vertical development can grow to heights in

excess of &',::: feet, releasing incredible amounts of energy. The two types of clouds with

vertical development are fair weather cumulus and cumulonimbus.

34 $air weather cumulus clouds have the appearance of floating cotton balls and

have a lifetime of @ to : minutes. Gnown for their flat bases and distinct outlines,

fair weather cumulus exhibit only slight vertical growth, with the cloud tops

designating the limit of the rising air. ?iven suitable conditions, however, these

clouds can later develop into towering cumulonimbus clouds associated with


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powerful thunderstorms. $air weather cumulus clouds are fueled by buoyant bubbles

of air !nown as thermals that rise up from the earths surface. As the air rises, the

water vapor cools and condenses forming water droplets. Eoung fair weather

cumulus clouds have sharply defined edges and bases while the edges of older

clouds appear more ragged, an artifact of erosion. Bvaporation along the cloud edges

cools the surrounding air, ma!ing it heavier and producing sin!ing motion outsidethe cloud. This downward motion inhibits further convection and growth of

additional thermals from down below, which is why fair weather cumulus typically

have expanses of clear s!y between them. ithout a continued supply of rising air,

the cloud begins to erode and eventually disappears.

394 2umulonimbus clouds are much larger and more vertically developed than fair

weather cumulus 3$igure #'4. They can exist as individual towers or form a line of

towers called a squall line. $ueled by vigorous convective updrafts, the tops of

cumulonimbus clouds can reach &',::: feet or higher. 0ower levels of

cumulonimbus clouds consist mostly of water droplets while at higher elevations,

where the temperatures are well below free%ing, ice crystals dominate thecomposition.


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then the surrounding air and accelerates bac! upwards towards its original height.

Another name for this type of cloud is the lenticular cloud.

394 0enticular clouds are cloud caps that often form above pinnacles and pea!s, and

usually indicate higher winds aloft 3$igure #:4. 2loud caps with a lens shape,

similar to a Dflying saucer,D indicate extremely high winds 3over : !nots4.0enticulars should always be watched for changes. f they grow and descend, bad

weather can be expected.

Fi/ure &


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mixing of the warm and cold layers. Temperature inversions are common in the

mountainous regions of the arctic, subarctic, and mid#latitudes.

b. At high altitudes, solar heating is responsible for the greatest temperature contrasts. More

sunshine and solar heat are received above the clouds than below. The important effect of

altitude is that the suns rays pass through less of the atmosphere and more direct heat isreceived than at lower levels, where solar radiation is absorbed and reflected by dust and

water vapor. -ifferences of : to @: degrees $ahrenheit may occur between surface

temperatures in the shade and surface temperatures in the sun. This is particularly true for

dar! metallic ob"ects. The difference in temperature felt on the s!in between the sun and

shade is normally ( degrees $ahrenheit. /pecial care must be ta!en to avoid sunburn and

snow blindness. 1esides permitting rapid heating, the clear air at high altitudes also favors

rapid cooling at night. 2onsequently, the temperature rises fast after sunrise and drops

quic!ly after sunset. Much of the chilled air drains downward, due to convection currents, so

that the differences between day and night temperatures are greater in valleys than on

slopes.

c. 0ocal weather patterns force air currents up and over mountaintops. Air is cooled on the

windward side of the mountain as it gains altitude, but more slowly 3&.9 degrees $ahrenheit

per ,::: feet4 if clouds are forming due to heat release when water vapor becomes liquid.

*n the leeward side of the mountain, this heat gained from the condensation on the

windward side is added to the normal heating that occurs as the air descends and air pressure

increases. Therefore, air and winds on the leeward slope are considerably warmer than on

the windward slope, which is referred to as 2hinoo! winds. The heating and cooling of the

air affects planning considerations primarily with regard to the clothing and equipment

needed for an operation.

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a cold front moves &:: miles during a 9#hour period, we can predict that it will

travel &:: miles in another 9#hours.

3&4 Climatolog+ Met"od.This method averages weather statistics accumulated over

many years. This only wor!s well when the pattern is similar to the following years.

34(nalog Met"od.This method examines a days forecast and recalls a day in the

past when the weather loo!ed similar 3an analogy4. This method is difficult to use

because finding a perfect analogy is difficult.

3@4'umerical &eat"er Prediction.This method uses computers to analy%e all

weather conditions and is the most accurate of the five methods.

&(. REC#R'I%- 'ATA

An accurate observation is essential in noting trends in weather patterns. deally, under changing

conditions, trends will be noted in some weather parameters. 5owever, this may not always be thecase. A minor shift in the winds may signal an approaching storm.

a. =ind 'irection.Assess wind direction as a magnetic direction from which the wind is

blowing.

b. =ind !peed.Assess wind speed in !nots.

34 f an anemometer is available, assess speed to the nearest !not.

394 f no anemometer is available, estimate the speed in !nots. Hudge the wind speed

by the way ob"ects, such as trees, bushes, tents, and so forth, are blowing.

c. 9isibility in "eters.*bserve the farthest visible ma"or terrain or man#made feature and

determine the distance using any available map.

d. Present =eather.nclude any precipitation or obscuring weather. The following are

examples of present weather>

7ainCcontinuous and steady liquid precipitation that will last at least one hour.

7ain showersCshort#term and potentially heavy downpours that rarely last more

than one hour. /nowCcontinuous and steady fro%en precipitation that will last at least one hour.

/now showersCshort#term and potentially heavy fro%en downpours that rarely last

more than one hour.

$og, ha%eCobstructs visibility of ground ob"ects.

ThunderstormsCa potentially dangerous storm. Thunderstorms will produce

lightning, heavy downpours, colder temperatures, tornadoes 3not too frequently4,

hail, and strong gusty winds at the surface and aloft. inds commonly exceed &@

!nots.

e. Total Cloud Co>er.Assess total cloud cover in eighths. -ivide the s!y into eight different

sections measuring from hori%on to hori%on. 2ount the sections with cloud cover, whichgives the total cloud cover in eighths. 3$or example, if half of the sections are covered with

clouds, total cloud cover is J.4


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f. Ceilin/ Hei/ht.Bstimate where the cloud base intersects elevated terrain. =ote if bases

are above all terrain. f clouds are not touching terrain, then estimate to the best of your

ability.

g. Temperature. Assess temperature with or without a thermometer.

34 ith a thermometer, assess temperature in degrees 2elsius 3use $ahrenheit only

if 2elsius conversion is not available4. To convert $ahrenheit to 2elsius> 2 N $ minus

&9 times .@@. To convert 2elsius to $ahrenheit> $ N . times 2 plus &9.

E?ample@ degrees $ O &9 x .@@ N @ degrees 2.

@ degrees 2 x . I &9 N degrees $.

394 ithout a thermometer, estimate temperature as above or below free%ing 3:o24,

as well as an estimated temperature.

h. Pressure Trend.ith a barometer or altimeter, assess the pressure trend.

34 A high pressure moving in will cause altimeters to indicate lower elevation.

394 A low pressure moving in will cause altimeters to indicate higher elevation.

i. #bser>ed =eather.=ote changes or trends in observed weather conditions.

34 -eteriorating trends include>

Mar!ed wind direction shifts. A high pressure system wind flows cloc!wise.

A low pressure system wind flows countercloc!wise. The closer the isometric

lines are, the greater the differential of pressure 3greater wind speeds4.

Mar!ed wind speed increases.

2hanges in obstructions to visibility.

ncreasing cloud coverage.

ncrease in precipitation. A steady dri%%le is usually a long#lasting rain.

0owering cloud ceilings.

Mar!ed cooler temperature changes, which could indicate that a cold front is

passing through.

Mar!ed increase in humidity. -ecreasing barometric pressure, which indicates a lower pressure system is

moving through the area.

394 mproving trends include>

/teady wind direction, which indicates no change in weather systems in the

area.

-ecreasing wind speeds.

2learing of obstructions to visibility.

-ecreasing or ending precipitation.

-ecreasing cloud coverage. ncreasing height of cloud ceilings.

Temperature changes slowly warmer.


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5umidity decreases.

ncreasing barometric pressure, which indicates that a higher pressure system

is moving through the area.

". $pdate.2ontinue to evaluate observed conditions and update the forecast.

!ection III. "#$%TAI% HA7AR'!

5a%ards can be termed natural 3caused by natural occurrence4, man#made 3caused by an individual,

such as lac! of preparation, carelessness, improper diet, equipment misuse4, or as a combination

3human trigger4. There are two !inds of ha%ards while in the mountainsCsub"ective and ob"ective.

2ombinations of ob"ective and sub"ective ha%ards are referred to as cumulative ha%ards.

&((. !$5ECTI9E HA7AR'!

Sub"ectiveha%ards are created by humans; for example, choice of route, companions, overexertion,

dehydration, climbing above ones ability, and poor "udgment.

a. Fallin/.$alling can be caused by carelessness, over#fatigue, heavy equipment, bad

weather, overestimating ability, a hold brea!ing away, or other reasons.

b. 5i>ouac !ite.1ivouac sites must be protected from roc!fall, wind, lightning, avalanche

run#out %ones, and flooding 3especially in gullies4. f the possibility of falling exists, rope in,

the tent and all equipment may have to be tied down.

c. Equipment.7opes are not total security; they can be cut on a sharp edge or brea! due to

poor maintenance, age, or excessive use. Eou should always pac! emergency and bivouac

equipment even if the weather situation, tour, or a short climb is seemingly low of dangers.

&(). #5ECTI9E HA7AR'!

#b"ectiveha%ards are caused by the mountain and weather and cannot be influenced by man; for

example, storms, roc!falls, icefalls, lightning, and so on.

a. Altitude.At high altitudes 3especially over ),@:: feet4, endurance and concentration is

reduced. 2ut down on smo!ing and alcohol. /leep well, acclimati%e slowly, stay hydrated,

and be aware of signs and symptoms of high#altitude illnesses. /torms can form quic!ly and

lightning can be severe.

b. 9isibility.$og, rain, dar!ness, and or blowing snow can lead to disorientation. Ta!e note

of your exact position and plan your route to safety before visibility decreases. 2old

combined with fog can cause a thin sheet of ice to form on roc!s 3verglas4. hiteout

conditions can be extremely dangerous. f you must move under these conditions, it is best

to rope up. 5ave the point man move to the end of the rope. The second man will use the

first man as an aiming point with the compass.


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d. Rocfall.1loc!s and scree at the base of a climb can indicate recurring roc!fall. 0ight

colored spots on the wall may indicate impact chips of falling roc!. /pring melt or warming

by the sun of the roc!JiceJsnow causes roc!fall.

e. A>alanches.Avalanches are caused by the weight of the snow overloading the slope.

37efer toparagraph #9@for more detailed information on avalanches.4

f. Han/in/ -laciers and !eracs.Avoid, if at all possible, hanging glaciers and seracs. They

will fall without warning regardless of the time of day or time of year. *ne cubic meter of

glacier ice weighs ': !ilograms 3about 9,::: pounds4. f you must cross these danger

areas, do so quic!ly and !eep an interval between each person.

g. Cre>asses.2revasses are formed when a glacier flows over a slope and ma!es a bend, or

when a glacier separates from the roc! walls that enclose it. A slope of only two to three

degrees is enough to form a crevasse. As this slope increases from 9@ to &: degrees,

ha%ardous icefalls can be formed. 0i!ewise, as a glacier ma!es a bend, it is li!ely that

crevasses will form at the outside of the bend. Therefore, the safest route on a glacier wouldbe to the inside of bends, and away from steep slopes and icefalls. Bxtreme care must be

ta!en when moving off of or onto the glacier because of the moat that is most li!ely to be

present.

&(3. =EATHER HA7AR'!

eather conditions in the mountains may vary from one location to another as little as :

!ilometers apart. Approaching storms may be hard to spot if mas!ed by local pea!s. A clear, sunny

day in Huly could turn into a snowstorm in less than an hour. Always pac! some sort of emergency

gear.

a. inds are stronger and more variable in the mountains; as wind doubles in speed, the

force quadruples.

b. +recipitation occurs more on the windward side than the leeward side of ranges. This

causes more frequent and denser fog on the windward slope.

c. Above approximately ,::: feet, snow can be expected any time of year in the temperate

climates.

d. Air is dryer at higher altitudes, so equipment does not rust as quic!ly, but dehydration isof greater concern.

e. 0ightning is frequent, violent, and normally attracted to high points and prominent

features in mountain storms. /igns indicative of thunderstorms are tingling of the s!in, hair

standing on end, humming of metal ob"ects, crac!ling, and a bluish light 3/t. Blmos fire4 on

especially prominent metal ob"ects 3summit crosses and radio towers4.

34 Avoid pea!s, ridges, roc! walls, isolated trees, fixed wire installations, crac!s that

guide water, crac!s filled with earth, shallow depressions, shallow overhangs, and

roc! needles. /ee! shelter around dry, clean roc! without crac!s; in scree fields; or in

deep indentations 3depressions, caves4. Geep at least half a bodys length away froma cave wall and opening.
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394 Assume a one#point#of#contact body position. /quat on your haunches or sit on a

ruc!sac! or rope. +ull your !nees to your chest and !eep both feet together. f half

way up the roc! face, secure yourself with more than one pointClightning can burn

through rope. f already rappelling, touch the wall with both feet together and hurry

to the next anchor.

f. -uring and after rain, expect slippery roc! and terrain in general and ad"ust movement

accordingly. Bxpect flash floods in gullies or chimneys. A climber can be washed away or

even drowned if caught in a gully during a rainstorm. 1e especially alert for falling ob"ects

that the rain has loosened.

g. -angers from impending high winds include frostbite 3from increased wind#chill factor4,

windburn, being blown about 3especially while rappelling4, and debris being blown about.

ear protective clothing and plan the route to be finished before bad weather arrives.

h. $or each ::#meter rise in altitude, the temperature drops approximately one degree

$ahrenheit. This can cause hypothermia and frostbite even in summer, especially whencombined with wind, rain, and snow. Always wear or pac! appropriate clothing.

i. f it is snowing, gullies may contain avalanches or snow sloughs, which may bury the trail.

/nowshoes or s!is may be needed in autumn or even late spring.


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Table &(. A>alanche haBard e>aluation checlist.

a. !lope !tability./lope stability is the !ey factor in determining the avalanche danger.

34loe (ngle./lopes as gentle as @ degrees have avalanched. Most avalanches

occur on slopes between &: and @ degrees. /lopes above ): degrees often do not

build up significant quantities of snow because they are too steep.

394loe Pro/ile.-angerous slab avalanches are more li!ely to occur on convex

slopes, but may occur on concave slopes.

3&4loe (sect./now on north facing slopes is more li!ely to slide in midwinter./outh facing slopes are most dangerous in the spring and on sunny, warm days.

/lopes on the windward side are generally more stable than leeward slopes.

34 0round Cover.7ough terrain is more stable than smooth terrain. *n grassy

slopes or scree, the snow pac! has little to anchor to.

b. Tri//ers.Farious factors trigger avalanches.

34 !emerature.hen the temperature is extremely low, settlement and adhesion

occur slowly. Avalanches that occur during extreme cold weather usually occur

during or immediately following a storm. At a temperature "ust below free%ing, thesnowpac! stabili%es quic!ly. At temperatures above free%ing, especially if

temperatures rise quic!ly, the potential for avalanche is high. /torms with a rise in


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temperature can deposit dry snow early, which bonds poorly with the heavier snow

deposited later. Most avalanches occur during the warmer midday.

394Preciitation.About ': percent of avalanches occur during or within twenty#four

hours after a snowstorm. The rate at which snow falls is important. 5igh rates of

snowfall 39.@ centimeters per hour or greater4, especially when accompanied bywind, are usually responsible for ma"or periods of avalanche activity. 7ain falling on

snow will increase its weight and wea!ens the snowpac!.

3&4 &ind./ustained winds of @ miles per hour and over transport snow and form

wind slabs on the lee side of slopes.

34 &eig"t.Most victims trigger the avalanches that !ill them.

3@4Vi)ration.+assing helicopters, heavy equipment, explosions, and earth tremors

have triggered avalanches.

c. !no0 Pits./now pits can be used to determine slope stability.

34 -ig the snow pit on the suspect slope or a slope with the same sun and wind

conditions. /now deposits may vary greatly within a few meters due to wind and sun

variations. 3*n at least one occasion, a snow pit dug across the fall line triggered the

suspect slope4. -ig a 9#meter by 9#meter pit across the fall line, through all the snow,

to the ground. *nce the pit is complete, smooth the face with a shovel.

394 2onduct a shovel shear test.

3a4 A shovel shear test puts pressure on a representative sample of the

snowpac!. The core of this test is to isolate a column of the snowpac! from

three sides. The column should be of similar si%e to the blade of the shovel.

-ig out the sides of the column without pressing against the column with the

shovel 3this affects the strength4. To isolate the rear of the column, use a rope

or string to saw from side to side to the base of the column.

3b4 f the column remained standing while cutting the rear, place the shovel

face down on the top of the column. Tap with varying degrees of strength on

the shovel to see what force it ta!es to create movement on the bed of the

column. The surface that eventually slides will be the layer to loo! at closer.This test provides a better understanding of the snowpac! strength. $or

greater results you will need to do this test in many areas and formulate a

scale for the varying methods of tapping the shovel.

3&4 2onduct a 7utschbloc! test. To conduct the test, isolate a column slightly longer

than the length of your snowshoes or s!is 3same method as for the shovel shear test4.

*ne person moves on their s!is or snowshoes above the bloc! without disturbing the

bloc!. *nce above, the person carefully places one showshoe or s!i onto the bloc!

with no body weight for the first stage of the test. The next stage is adding weight to

the first leg. =ext, place the other foot on the bloc!. f the bloc! is still holding up,

squat once, then twice, and so on. The remaining stage is to "ump up and land on thebloc!.


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d. Types of !no0 A>alanches.There are two types of snow avalanches> loose snow 3point4

and slab.

34 0oose snow avalanches start at one point on the snow cover and grow in the

shape of an inverted DF.D Although they happen most frequently during the winter

snow season, they can occur at any time of the year in the mountains. They often fallas many small sluffs during or shortly after a storm. This process removes snow from

steep upper slopes and either stabili%es lower slopes or loads them with additional

snow.

394 et loose snow avalanches occur in spring and summer in all mountain ranges.

0arge avalanches of this type, lubricated and weighed down by meltwater or rain can

travel long distances and have tremendous destructive power. 2oastal ranges that

have high temperatures and frequent rain are the most common areas for this type of

avalanche.

3&4 /lab avalanches occur when cohesive snow begins to slide on a wea! layer. Thefracture line where the moving snow brea!s away from the snowpac! ma!es this

type of avalanche easy to identify. /lab release is rapid. Although any avalanche can

!ill you, slab avalanches are generally considered more dangerous than loose snow

avalanches.

3a4 Most slab avalanches occur during or shortly after a storm when slopes

are loaded with new snow at a critical rate. The old rule of never travel in

avalanche terrain for a few days after a storm still holds true.

3b4 As slabs become harder, their behavior becomes more unpredictable; they

may allow several people to s!i across before releasing. Many experts believe

they are susceptible to rapid temperature changes. +ac!ed snow expands and

contracts with temperature changes. $or normal density, settled snow, a drop

in temperature of : degrees 2elsius 3 degrees $ahrenheit4 would cause a

snow slope &:: meters wide to contract 9 centimeters. Barly s!i mountaineers

in the Alps noticed that avalanches sometimes occurred when shadows struc!

a previously sun#warmed slope.

d. Protecti>e "easures.Avoiding !nown or suspected avalanche areas is the easiest method

of protection. *ther measures include>

34Personal a/et+.7emove your hands from s!i pole wrist straps. -etach s!i

runaway cords. +repare to discard equipment. +ut your hood on. 2lose up your

clothing to prepare for hypothermia. -eploy avalanche cord. Ma!e avalanche probes

and shovels accessible. Geep your pac! on at all timesCdo not discard. Eour pac!

can act as a flotation device, as well as protect your spine.

394 0rou a/et+./end one person across the suspect slope at a time with the rest of

the group watching. All members of the group should move in the same trac! from

safe %one to safe %one.

e. Route !election./electing the correct route will help avoid avalanche prone areas, whichis always the best choice. Always allow a wide margin of safety when ma!ing your decision.


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34 The safest routes are on ridge tops, slightly on the windward side; the next safest

route is out in the valley, far from the bottom of slopes.

394 Avoid cornices from above or below. /hould you encounter a dangerous slope,

either climb to the top of the slope or descend to the bottomCwell out of the way of

the run#out %one. f you must traverse, pic! a line where you can traverse downhill asquic!ly as possible. hen you must ascend a dangerous slope, climb to the side of

the avalanche path, and not directly up the center.

3&4 Ta!e advantage of dense timber, ridges, or roc!y outcrops as islands of safety.


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3)4 Try to relax. f you feel yourself about to pass out, do not fight it. The respiration

of an unconscious person is more shallow, their pulse rate declines, and the body

temperature is lowered, all of which reduce the amount of oxygen needed. 3/ee

Appendix 2for information on search and rescue techniques.4

CHAPTER (

MOUNTAIN LIVING

nits deploying to high elevations must receive advanced training to survive in the harsh

mountain environment. $ormal activities %navigation, communications, and movement&

require specialized techniques. 'raining should be conducted as realistically as possible,

preferably under severe conditions so the soldier gains confidence. ()tended training

e)ercises test support facilities and e)pose the soldier to the isolation common to mountain

operations. 'raining should reflect the harsh mountain environment and should considerthe following*

Temperature and altitude extremes.

5ygiene and sanitation.

0imited living space 3difficulty of bivouac4.

2lothing requirements.

!ection I. !$R9I9A+

The soldier trained to fight and survive in a mountain environment will have increased confidence

in himself. Training should include> psychological preparation, locating water, shelter

considerations, fire building, health ha%ards, and techniques for obtaining food 3see $M 9#()4.

(&. =ATER !$PP+,

Mountain water should never be assumed safe for consumption. Training in water discipline should

be emphasi%ed to ensure soldiers drin! water only from approved sources. $luids lost through

respiration, perspiration, and urination must be replaced if the soldier is to operate efficiently.

a. Maintaining fluid balance is a ma"or problem in mountain operations. The sense of thirstmay be dulled by high elevations despite the greater threat of dehydration. 5yperventilation

and the cool, dry atmosphere bring about a three# to four#fold increase in water loss by

evaporation through the lungs. 5ard wor! and overheating increase the perspiration rate.

The soldier must ma!e an effort to drin! liquids even when he does not feel thirsty. *ne

quart of water, or the equivalent, should be drun! every four hours; more should be drun! if

the unit is conducting rigorous physical activity.

b. Three to six quarts of water each day should be consumed. About (@ percent of the human

body is liquid. All chemical activities in the body occur in water solution, which assists in

removing toxic wastes and in maintaining an even body temperature. A loss of two quarts of

body fluid 39.@ percent of body weight4 decreases physical efficiency by 9@ percent, and aloss of 9 quarts 3@ percent of body weight4 is usually fatal. /alt lost by sweating should be

replaced in meals to avoid a deficiency and subsequent cramping. 2onsuming the usual
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military rations 3three meals a day4 provides sufficient sodium replacement. /alt tablets are

not necessary and may contribute to dehydration.

c. Bven when water is plentiful, thirst should be satisfied in increments. 6uic!ly drin!ing a

large volume of water may actually slow the soldier. f he is hot and the water is cold, severe

cramping may result. A basic rule is to drin! small amounts often. +ure water should alwaysbe !ept in reserve for first aid use. Bmphasis must be placed on the three rules of water

discipline>

-rin! only treated water.

2onserve water for drin!ing. +otable water in the mountains may be in short supply.

-o not contaminate or pollute water sources.

d. /now, mountain streams, springs, rain, and la!es provide good sources of water supply.

+urification must be accomplished, however, no matter how clear the snow or water

appears. $ruits, "uices, and powdered beverages may supplement and encourage water inta!e

3do not add these until the water has been treated since the purification tablets may notwor!4. /oldiers cannot ad"ust permanently to a decreased water inta!e. f the water supply is

insufficient, physical activity must be reduced. Any temporary deficiency should be replaced

to maintain maximum performance.

e. All water that is to be consumed must be potable. -rin!ing water must be ta!en only from

approved sources or purified to avoid disease or the possible use of polluted water. Melting

snow into water requires an increased amount of fuel and should be planned accordingly.

=onpotable water must not be mista!en for drin!ing water. ater that is unfit to drin!, but

otherwise not dangerous, may be used for other purposes such as bathing. /oldiers must be

trained to avoid wasting water. Bxternal cooling 3pouring water over the head and chest4 is a

waste of water and an inefficient means of cooling. -rin!ing water often is the best way to

maintain a cool and functioning body.

f. ater is scarce above the timberline. After setting up a perimeter 3patrol base, assembly

area, defense4, a watering party should be employed. After sundown, high mountain areas

free%e, and snow and ice may be available for melting to provide water. n areas where water

tric!les off roc!s, a shallow reservoir may be dug to collect water 3after the sediment

settles4. ater should be treated with purification tablets 3iodine tablets or calcium

hypochlorite4, or by boiling at least one to two minutes. $iltering with commercial water

purification pumps can also be conducted. /olar stills may be erected if time and sunlight

conditions permit 3see $M 9#()4. ater should be protected from free%ing by storing itnext to a soldier or by placing it in a sleeping bag at night. ater should be collected at

midday when the sun thaw available.

(&(. %$TRITI#%

/uccess in mountain operations depends on proper nutrition. 1ecause higher altitudes affect eating

habits, precautions must be ta!en. f possible, at least one hot meal each day should be eaten, which

may require personnel to heat their individual rations.

a. The following elements are characteristic of nutritional acclimati%ation in mountain

operations>

eight loss during the first two to three days at high elevation.
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34 Vitamins.Fitamins are classified into two groups on the basis of their ability to

dissolve in fat or water. The fat#soluble vitamins include vitamins A, -, B, and G.

The water#soluble vitamins include the 1 vitamins and vitamin 2, which are found in

cereals, vegetables, fruits, and meats. A well#balanced diet provides all of the

required vitamins. /ince most water#soluble vitamins are not stored, a proper diet is

necessary to ensure adequate levels of these vitamins. f an improper and unbalanceddiet is li!ely to occur during a deployment, vitamin supplements should be

considered, especially if this period is to exceed : days.

[email protected] elements can be divided into two groups> those needed in the

diet in amounts of :: milligrams or more a day such as calcium, phosphorous, and

magnesium; and trace elements needed in amounts of only a few milligrams a day

such as iodine, iron, and %inc. 7equired minerals are contained in a balanced diet

3meats, vegetables, fruits4.

d. Bating a balanced diet provides the energy needed to conduct daily activities and to

maintain the internal body processes. A balanced diet containing adequate amounts ofvitamins and minerals ensures an efficient metabolism. /ince climbing is a strenuous

activity and demands high#energy use, a balanced diet is a necessity.

34 The efficiency of the body to wor! above the basal metabolism varies from 9: to

: percent, depending on the soldier. *ver @: percent of caloric inta!e is released as

heat and is not available when the soldier wor!s. 3About ,@:: calories are expended

for strenuous wor! and &,@:: calories for garrison activity.4 5eat is a by#product of

exertion. Bxertion causes excessive bodily heat loss through perspiration and

increased radiation. -uring inactivity in cold weather, the metabolism may not

provide enough heat. The Dinternal thermostatD initiates and causes the muscles to

shiver, thus releasing heat. /hivering also requires energy and burns up to 99:

calories per hour 3estimated for a ::#pound man4.

394 ith an abrupt ascent to high altitudes, the soldier experiences physiological

acclimati%ation. The circulatory system labors to provide the needed oxygen to the

body. 0arge meals require the digestive system to wor! harder than usual to

assimilate food. 0arge meals may be accompanied by indigestion, shortness of

breath, cramps, and illness. Therefore, relatively light meals that are high in

carbohydrates are best while acclimati%ing at higher elevations. +ersonnel should eat

moderately and rest before strenuous physical activity. /ince fats and protein are

harder to digest, less digestive disturbances may occur if meals are eaten beforeresting. A diet high in carbohydrates is not as dense in energy and may require eating

more often. 2arbohydrates, beginning in the morning and continuing through mid#

afternoon, are important in maintaining energy levels.

3&4 Bxtra food should be carried in case resupply operations fail. $ood should be

lightweight and easy to digest, and be eaten hot or cold. Meals#ready#to#eat 3M7Bs4

meet these criteria and provide all of the basic food groups. 2ommanders may

consider supplementing M7Bs with brea!fast bars, fruits, "uices, candies, cereal

bars, and chocolate. 1ouillon cubes can replace water and salt as well as warming

cold bodies and stimulating the appetite. 5ot beverages of soup, "uices, powdered

mil!, and cider should also be considered. /ince coffee, tea, and hot chocolate arediuretics, the consumption of these beverages should not be relied upon for

hydration.


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changing soc!s, soldiers should closely examine their feet for wrin!les, crac!s,

blisters, and discoloration. =ails should be trimmed but not too short. 0ong nails

wear out soc!s; short nails do not provide proper support for the ends of the toes.

Medical attention should be sought for any possible problems.

3&4 $eet should be sprayed two or three times a day with an aluminum chlorohydrateantiperspirant for a wee! and then once a day for the rest of the winter. f fissures or

crac!s occur in the feet, it is best to discontinue spraying until they are healed or to

spray less often to control sweating. This process stops about (: percent of the

sweating in the feet.

34 -uring periods of extreme cold, there is a tendency for the soldier to become

constipated. This condition is brought about by the desire to avoid the inconvenience

and discomfort of defecating. Adequate water inta!e plus a low protein, high

roughage diet can be helpful in preventing constipation.

b. !anitation.n roc!y or fro%en ground, digging latrines is usually difficult. f latrines areconstructed, they should be located downwind from the position and buried after use. n

tactical situations, the soldier in a designated, downwind location away from water sources

may dig Dcat holes.D /ince waste free%es, it can be covered with snow and ice or pushed

down a crevasse. n roc!y areas above the timberline, waste may be covered with stones.

!ection II. ACC+I"ATI7ATI#% A%' C#%'ITI#%I%-

Terrestrial altitude can be classified into five categories. 0ow altitude is sea level to @,::: feet.

5ere, arterial blood is ') percent saturated with oxygen in most people. Moderate altitude is from

@,::: to ,::: feet. At these altitudes, arterial blood is greater than '9 percent saturated with

oxygen, and effects of altitude are mild and temporary. 5igh altitude extends from ,::: to ,:::

feet, where arterial blood oxygen saturation ranges from '9 percent down to : percent. Altitude

illness is common here. Fery high altitude is the region from ,::: to ,::: feet, where altitude

illness is the rule. Areas above ,::: feet are considered extreme altitudes.

/oldiers deployed to high mountainous elevations require a period of acclimati%ation before

underta!ing extensive military operations. The expectation that freshly deployed, unacclimati%ed

troops can go immediately into action is unrealistic, and could be disastrous if the opposing force is

acclimati%ed. Bven the physically fit soldier experiences physiological and psychological

degradation when thrust into high elevations. Time must be allocated for acclimati%ation,

conditioning, and training of soldiers. Training in mountains of low or medium elev

MILITARY MOUNTAINEERING FM 3-97.61

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