Motor Transport Problems in French Equatorial Africa, WWII Tactical and Technical Trends, No. 14, December 17, 1942 (Lone Sentry)

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 whenever possible.

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 potassium permanganate.

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.

(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 such kits.

(g) Motor transport companies should be issued certain navigating equipment and personnel should be instructed in the use of same.