In view of the high degree of motorization in our army and the worldwide
operations of our forces, the problems of motor transport movements over
difficult terrain are of particular importance. A report on the difficulties
encountered by the Free French in motor movements between certain points in
French Equatorial Africa is therefore of interest.
The route in question is about 500 miles long. The first 300 miles are
covered by a two-lane clay-surfaced road with occasional sandy stretches; little, if
any, road maintenance is undertaken. Over the remaining 200 miles, the
route is a desert trail, and it is over this portion that most of the
transport problems are encountered.
The difficulty of the route can readily be appreciated when it is realized
that a round trip normally takes a month (some vehicles have required
even 6 weeks despite the fact that they had no motor trouble), and
the weight of gasoline, lubricants, and water consumed per truck is 1 1/2 tons.
The major difficulties which must be overcome are heavy rains, sand, and
heat; also the lack of water, refueling points, and maintenance facilities.
The rainy season lasts for about 3 months. However, it affects only the
first 50 miles. After a heavy downpour, roads are usually impassable
for about 2 days.
Over the last 200 miles, frequent sandstorms reduce visibility to a very
few yards and make the wearing of goggles essential. Vehicles frequently bog
down in the sand, and much time is thereby lost because of the difficulty of
extricating them. Even if there were roads in this area, they would be covered
by shifting sands in a single day; furthermore, the trail itself changes
frequently because of the shifting sand. Hence, native guides must be employed
to lead convoys over firm ground and at the same time maintain direction. Were
the necessary navigating equipment available, it might be practical to navigate across
this area as across a sea. A partial effort has been made in this direction
by painting on the hoods of some vehicles a crude sundial arrangement
which serves as a rough compass.
Sand fouls carburetors, gas lines, and engines, and as a result vehicles
must be completely overhauled every 6,000 miles; this generally calls
for new piston rings, oil and air filters, and clutch plates, and occasionally
new piston-rod bearings, new differentials, and new transmissions. Experience
has also taught that an oil of exceptionally high viscosity must be
used (S.A.E. 60 or 70). Furthermore, the sand makes necessary the frequent
use of low gear, which means greater wear on the engine, overheating, and
greater gas and oil consumption. Tires also wear more rapidly; the
increased friction not only wears the tire badly, but also results
in overheating which causes blowouts.
Not many precautionary measures can be taken against the sand. As far
as helpful equipment is concerned, each truck should be equipped with a shovel
and two metal plates, pieces of wire mesh, or similar material for use under
the wheels when the truck is trapped in the sand. The French have improvised
a very satisfactory system for use on trucks having 4-wheel drive on the rear
axle. They use two rough-hewn poles having a diameter slightly larger than the
distance between the inflated tires on the same side of the axle. By placing the
poles between the tires on each side of the axle, the truck is virtually able to
climb the poles to firmer ground. Treadless tires are recommended, on the
theory that treads tend to cut through the hard crust of the sand, whereupon the
vehicle will bog down.
Military and civilian transportation authorities in this area agree that a truck
especially designed for the desert is a necessity; they claim that the Italians
have such a truck operating effectively in the Libyan desert. Its general
characteristics are: 8- to 10-ton maximum load, large tires (4 feet 6 inches in
diameter), 4-wheel rear axle drive, super-low gear, and large horsepower. They
maintain that this truck has been able to go anywhere in the desert without
fear of bogging down in the sand.
The extremely hot weather causes both engine and tires to overheat. Because
of the intense heat of the sun and because of the friction of the tires on
the roadbed, the tires often become too hot to touch. This results in increased
pressure. Unless tires are periodically deflated (dependent on the heat, but
generally hourly) so as to maintain a constant pressure, there is great
danger of blowouts. Tubes have been known to literally explode into as
many as 16 separate pieces simply because this elementary precaution
was not observed.
Because tires must be deflated periodically, each vehicle should carry a tire gauge, so
that the tire pressure can be accurately checked. Obviously, at the end
of a day's run tire pressures will be low and will have to be increased
before the departure the next day. For this reason and also because of the high
incidence rate of blowouts, one truck in five should be equipped with an air
compressor which runs off the motor. In convoys, there should be a minimum of
two trucks so equipped, so that in case one must drop out of the convoy for any
reason whatsoever, there will always be another left. Also because of frequent
blowouts, each vehicle should be equipped with two spare tires and two additional
new inner tubes. Experience has demonstrated that cold patches do not hold
when inner tubes become hot; evidently the rubber cement melts. Consequently, repair
kits should contain materials for vulcanizing patches onto tubes. Four other
precautions which are generally taken are: (a) Vehicles are not driven during the
hot part of the day (1100 - 1530) except in emergency. (b) Driving is frequently
done at night. (c) Whenever tires are deflated en route, they are also
doused with water. (d) During halts vehicles are always parked in the shade
Water is always a great problem in this region, not only because of its
scarcity but also because of its impurity. One can ordinarily obtain water along
the route by stopping at native villages. It is not potable, however, and can be
used only for filling the radiator or cooling the tires. Drinking water is
habitually carried in each vehicle; the quantity consumed during the day is replaced
at the end of the day's journey. In order to do this, the water has to be treated
in some manner; i.e., filtered, boiled, or treated with some chemical such as
The problem of carrying drinking water can be solved by mounting a 10-gallon
barrel, with spigot or detachable plug, on the running board of each
vehicle. This is the preferred position, because of the ease of getting at it. It
should be detachable and should be so constructed such that the inside can be cleaned
periodically. This container should be covered with an inch-thick layer of
absorbent material; by soaking this covering, the contents will be cooled by the
subsequent evaporation of the water in the absorbent covering. In convoys this
drinking water should be supplemented by water carried in several four-wheel trailers.
Fuel is a problem because of the utter absence of European settlements. As
a consequence, gasoline and oil for an entire trip must be carried by each
vehicle. It is never desirable to put all of the fuel for several vehicles on one
truck, because if that truck breaks down, either the entire convoy must be
delayed for repairs to a single truck, or part of the load of each truck must be
discharged in order to take on gasoline for the remainder of the trip.
Lack of maintenance facilities is a major difficulty. It has not been
possible to establish repair shops along the route; when a truck breaks down on
the road, spare parts must be dispatched from the base shop and repairs then
made in the field. This results in long delays for repairs which otherwise
would require only a few hours.
The reporting officer makes the following recommendations:
(a) Vehicles sent to the desert should have as standard equipment: tire
gauge, 2 spare tires, 2 additional new inner tubes, vulcanizing patches,
10-gallon water container covered with absorbent material, 2 or 3 quart-size oil
containers, a shovel, and 2 pieces of flat metal or wire mesh 2 feet by 8 feet.
(b) One truck in five should have a mounted air compressor, run off
the motor, for inflating tires. This ratio should be preserved in convoys, that
there should be a minimum of two such trucks.
(c) Trailers of 500-gallon maximum capacity should be supplied for
hauling gasoline and drinking water for convoys.
(d) Standard American military and commercial trucks must be modified
for use in the desert, with attention being given to: super-low speeds, two
differential speeds, extra-large radiator, six- or eight-bladed fan, extra-large
oil and air filters, four- or six-wheel drive, treadless tires, and tires
of large diameter and great width.
(e) A truck similar to the Italian model should be especially designed for
use in the desert; i.e., having as characteristics 8- to 10-ton maximum load, 4-wheel
rear axle drive, super-low gears, high horsepower, tires of extra-large
diameter, and with the characteristics listed in the previous paragraph.
(f) Each truck should be equipped with a small medical kit containing
sodium hypochlorite or other pills for purifying water, as well as containing
quinine and such emergency medicines and bandages as are normally put in
(g) Motor transport companies should be issued certain navigating
equipment and personnel should be instructed in the use of same.