The effects of the desert environment on equipment
were described in Chapter 1. This appendix describes techniques
which, if used while operating equipment in the desert, can save
both equipment and lives.
Drivers and track commanders should observe the
guidelines in the following paragraphs while operating vehicles
in desert areas.
Wear goggles while driving open-hatched regardless
of visibility. Clear-lens goggles should be worn at night unless
night-vision goggles are used. Bandanas or surgical masks should
be worn to avoid breathing heavy dust.
Vehicles in an extended convoy should maintain
a dust distance of twice the normal interval, or as specified
in the unit SOP to allow time for the dust to dissipate. When
driving on extremely dusty roads or trails and if traffic conditions
permit, a staggered column formation can be used with vehicles
alternately driving on the left and right side of the road.
If the vehicles should become engulfed in dust,
the convoy commander should consider adjusting the rate of march
accordingly. Any commander of a vehicle engulfed in dust should
alert the convoy commander by radio, move to the right side of
the road, and stop or slow to allow the dust to dissipate. Extreme
caution must be observed to ensure oncoming and following vehicles
are not jeopardized. The lead vehicle must warn vehicles to return
to column formation if encountering traffic.
Sandy deserts may be relatively flat or interspersed
with windblown dunes. When driving in sand, the following techniques
should be applied:
- The best time to drive on sand is at night or
early morning when the sand is damp and traction is better. However,
this is not always the case especially with the newer type military
tires with closer tread design. Damp sand packs between the tread
in the grooves of these tires resulting in virtually no surface
- Drivers of track vehicles must be wary of a lack
of steering response, which indicates sand is building up between
the rear sprockets and treads. If the buildup of sand is allowed
to continue, it will force the tread off. "Shaking"
the vehicle with the steering or backing up will remove the sand.
- Wheel vehicles may gain some traction by reducing
the air pressure in the tires. However, prolonged driving on partially
deflated bias ply tires will overheat the tires and break down
the sidewalls. Vehicles equipped with radial tires or central
tire inflation system (CTIS) are not affected by the lower tire
pressure if the maximum speed listed in the operator's manual
is not exceeded.
- Vehicle loads must be evenly distributed. Rear-wheel
drive should be used where possible to prevent the front wheels
from digging into the sand and becoming mired.
- Drivers must switch to all-wheel drive or change
gears before a vehicle bogs down in the sand.
- Before entering the sand drivers should select
a gear that will allow the vehicle to maintain as much torque
as possible without causing the wheels to spin and to minimize
- Large-wheeled vehicles, such as 5,000-gallon
tankers, should have a designated "puller". The designated
vehicle should be preconfigured to assist these vehicles when
they become bogged down in loose sand.
Some sand areas will be covered by a surface
crust. This is caused by chemicals in the ground cementing sand
particles together, In many cases it will be possible to drive
on top of this crust and minimize dust signature and the chance
of bogging down. Consider the following techniques when driving
on a crust:
- Use staggered columns to facilitate movement.
As a general rule vehicles should not follow one behind the other.
- Ensure vehicles maintain a minimum speed (determined
from experience) below which they will break through the crust.
- Avoid sharp turns and abrupt starts or stops
that could cause a vehicle to break through the crust.
- Reconnoiter patches of the crust that are a different
shade to ensure they are not softer than the surrounding crust.
Crossing dunes requires careful reconnaissance.
Normally, the upwind side of the dune will be covered with a crust
and have a fairly gradual slope. The downwind side will be steeper
and have no crust. Prior to crossing a dune, the driver should
climb it on foot checking crust thickness, the angle at the crest
to ensure the vehicle will not become bellied at the top, and
the degree of slope and softness of the downwind side. If he is
satisfied his vehicle can climb the dune, he should drive the
vehicle straight up it at the best speed, crest it, and maintain
a controlled descent on the other side.
Little hills may be formed by the wind blowing
sand around small shrubs. Wheel vehicles should not attempt to
move through areas where this has occurred without engineer assistance.
Cacti or thorn bushes will cause frequent tire
punctures. Increase the number of tires carried in the unit's
PLL when operating in areas covered with this type of vegetation.
Rock and boulder-strewn areas, including lava
beds, may extend for many miles. Desert rocks, eroded and sharp-edged,
vary in size and are so numerous that it is almost impossible
to avoid any but the largest. The subsequent harsh jolting fatigues
individuals and causes extreme wear on tracks, wheels, springs,
and shock absorbers. Rocks and stones can become lodged between
the tires on vehicles equipped with dusk that can cause severe
damage to tires and brake components. Vehicles can follow one another in this type
of terrain and it may be feasible to reconnoiter and mark a route.
Drivers should achieve a "rolling" effect as they cross
large rocks by braking as the vehicle's wheels ride over a rock
so the axle settles relatively gently on the far side.
Salt marshes (called sebkha) are normally impassable,
the worst type being those with a dry crust of silt on top. Marsh
mud used on desert sand will, however, produce an excellent temporary
road. Many desert areas have salt marshes either in the center
of a drainage basin or near the seacoast. Old trails or paths
may cross the marsh, which are visible during the dry season but
not in the wet season. In the wet season standing water indicates
trails due to the crust being too hard or too thick for the water
to penetrate. However, such routes should not be tried by load-carrying
vehicles without prior reconnaissance and marking.
Track vehicle recovery methods are the same in
the desert as in temperate climates. The techniques described
in the following paragraphs will assist wheel vehicle recovery
operations in sand crusts or salt marshes. To assist in recovery,
wheel vehicles should carry the following items:
- Steel or aluminum channels, at least for the
driving wheels. These are pierced to reduce weight and ribbed
for strength. Pierced steel planking (PSP) or galvanized iron
maybe used as a substitute.
- Sand mats made of canvas, preferably with lateral
strips of metal to give strength and increase the traction of
- Jacks and jack blocks.
- Tow rope(s).
Once a vehicle becomes mired, excavate the ground
under the vehicle in a gradual slope towards the direction of
recovery to a point where no part of the underside is touching
the ground. Channels or spurs and mats are laid under or against
the wheels facing the direction of recovery. Tire pressure may
be reduced to increase traction, but this also lowers the vehicle.
It maybe necessary to lift the wheels with a jack if the vehicle
is resting on its frame or axles.
When the vehicle begins to move, any faltering
will cause it to sink again. Once out, the driver must maintain
speed until the vehicle has reached the nearest hard area. At
this point the tires are reinflated, the vehicle inspected for
damage, and recovery equipment collected.
Vehicles equipped with winches can winch themselves
out using ground anchors. The ground anchor may consist of a tarpaulin
full of sand placed in a hole and the winch cable attached to
it, or it may be one, or preferably two spare wheels well dug
A rubberized fabric balloon may be used on light
vehicles to lift them free of broken crust. The balloon is placed
under the vehicle and blown up with the vehicle exhaust.
If a lone vehicle breaks or bogs down in the
desert, the crew must stay with it. A vehicle is much easier to
find than a lone man.
Equipment directly affected by heat, such as aircraft and radios, are equally affected by all deserts. However, power trains and suspension systems are affected in proportion to trafficability and soil texture. Most damage to equipment can be avoided by careful driving and by careful observation by vehicle commanders.
Track tension must be correct as constant driving
on rocky plateau deserts will reduce the life of the track. Suspension
units will require frequent replacement of torsion bars and suspension
arms. To prevent damage to internal parts of the idler and suspension
arms caused by the terrain, direct-support maintenance units must
be provided with equipment capable of tapping and removing the
To prevent problems that can result when desert
vegetation clogs engine oil coolers and cylinder cooling pins,
place a small-mesh wire screen over the top grille doors. It may
still be necessary to remove packs about every 10 days to clean
the engine cooling fins. The wire screening should be periodically
checked, removed, and cleaned.
Maintenance personnel must inspect and adjust
transmission bands frequently, especially on vehicles operating
in hot, barren mountains. This will help reduce transmission oveheating.
NOTE: The Ml13A1 is especially
susceptible to overheating problems in desert conditions. This
includes the transmission and the solid-state voltage regulator,
which is more prone to overheating and early failure than the
older mechanical type.|
Extra stocks of air-cooled generators are necessary
because high-ambient temperatures limit their ability to maintain
the proper operating temperature and contribute to premature failure.
Wheeled vehicles are subject to brake system
component failures and power steering leaks on rocky deserts.
Vehicles equipped with manual transmissions are prone to clutch
failure caused by drivers slipping the clutch. Vehicles with automatic
transmissions tend to overheat; therefore, stop frequently to
allow the transmission time to cool. The M54 5-ton truck is prone
to air hydraulic cylinder failure and power steering seal leaks
on rocky deserts. All vehicles of the 1/4- to 5-ton range are
prone to clutch failure caused by drivers "riding" the
clutch pedal. Tire consumption is very high, so all vehicles must
carry one, or preferably two spare tires, and the unit's PLL of
tires should be considerably increased. Approximately one vehicle
in every three to four should carry slave cables to provide for
Vehicles should be equipped with the following:
- Extra fan belts.
- Two spare tires.
- Extra oil.
- Extra radiator hoses.
- Heavy duty tape.
- Extra air and fuel filters.
- Jack stand support plate.
- Sand ladders (fabricated) and matting.
- Tow rope/cable.
- Extra water cans.
- Siphoning hose and funnel.
- Slave cables.
Radios, regardless of type, must be kept cool
and clean. They must be in the shade whenever possible and should
be located in a ventilated area (or even in an air-conditioned
can). If water is available, wrap the radio in a damp towel, ensuring
that the air vents are not blocked. Additional radios should be
available in vital communications centers, such as tactical operations
centers, to allow immediate replacement if the set in use shows
signs of overheating.
It is essential that antennas be cut or adjusted
to the length of the operating frequency. Directional antennas
must be faced exactly in the required direction; approximate azimuth
produced by guesswork will not do. A basic whip antenna relies
on the capacitor effect between itself and the ground for efficient
propagation. The electrical ground may be very poor, and the antenna
performance alone may be degraded by as much as one-third if the
surface soil lacks moisture, which is normally the case in the
desert. If a ground-mounted antenna is not fitted with a counterpoise,
the ground around it should be dampened using any fluid available.
Vehicle-mounted antennas are more efficient if the mass of the
vehicle is forward of the antennas and is oriented towards the
Desert operations require dispersion, yet the
environment is likely to degrade the transmission range of radios,
particularly VHF (FM) fitted with secure equipment. This degradation
is most likely to recur in the hottest part of the day, approximately
1200 to 1700 hours.
If stations start to lose contact, especially
if the hotter part of the day is approaching, alternative communication
plans must be ready. Alternatives include the following:
- Using relay stations, including an airborne relay
station (the aircraft must remain at least 4,000 meters behind
the line of contact). Ground relay stations or RETRANS are also
useful and should be planned in conjunction with the scheme of
- Deploying any unemployed vehicle with a radio
as a relay between stations.
- Using alternative radio links such as VHF multichannel
telephones at higher levels, or HF (SSB) voice.
- Using wire. Normally wire will not be used as
operations will be fluid, but it maybe of some value in some static
- Using a unit such as all or part of the task force scout platoon for messenger service, Although it is undesirable to use such a unit in this manner, it may be necessary to maintain communications.
General tips for operating equipment in the desert
include the following:
- Check track tension daily.
- Check drive belt adjustment frequently.
- Lubricate suspension items daily, and clean grease
- Reduce sand ingestion by stretching nylon stockings
over air cleaners.
- Emphasize proper engine cooldown and shutdown
procedures, especially diesels.
- Adjust battery specific gravity to the environment
(refer to TMs).
- Set voltage regulators at lower end of specifications.
- Start up vehicles regularly to prevent discharge
- Increase stocks of oils and lubricants.
- Use high-grade 20W-50 oil; it serves well under
- Compensate for increased pressure due to severe
heat in closed pressurized systems.
- Check lubrication orders and TMs for the correct
viscosity of lubricants for higher temperatures.
- Keep lubrication to the absolute minimum on exposed
or semiexposed moving parts; this includes working parts of weapons.
- Erect screens against blowing sand in maintenance
- Cover the gap between the fuel nozzle and the
fuel tank filler neck opening during refueling operations.
- Protect exposed electrical cables and wires with
- Keep optics covered; clean them with a soft paintbrush
or a low-pressure air system (this works well for weapons also).
- Clean sand and dirt from hulls of armored vehicles.
- Check tire pressures and fuel levels at the midpoint
of the temperature range during the day.
- Ground all refueling equipment-STATIC ELECTRICITY
- Replenish radiators with potable water whenever
- Determine battery shortages early and requisition
- Drain fuel lines at night and in the morning
due to condensation.
- Increase PLLs for the following parts due to
high failure rates:
- All track components.
-All suspension components for both wheel and track vehicles.
- Brake shoes.
- Bearings and bushings.
-Plastic and rubber parts, including seals.
- All filters.
- Generator components.
- Deploy with plastic bags to cover weapons and
protect other equipment during maintenance or when not in use.
- Bring muzzle plugs.
- Prepare all vehicles for desert operations in
accordance with the appropriate TMs.
- Issue small paintbrushes to all soldiers/marines
for weapons cleaning and other equipment maintenance. The paintbrush
is one of the more valuable tools available to the soldier/marine
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