1. GENERAL

Military units operating in desert country or in regions which lack moisture in certain seasons soon find that dust is an aggressive enemy of men, vehicles, and weapons. Opposing forces engaged on such terrain discover that each faces an additional foe. Since in this global war it has been impossible to avoid operations in dust-ridden areas, and since the conflict may move to new theaters, equally dust-ridden, it is to a soldier's advantage to know as much as possible about the "capabilities" of this natural enemy.

2. EFFECTS ON MAN

When finely powdered dust is inhaled, it is likely to stick to the sensitive mucous membranes, drying up the natural moisture and forming hard crusts. Similarly, when dust enters the air passages of the throat and lungs, it serves as a sharp irritant, causing mucous accumulations and coughing. If the dust happens to contain such dangerous micro-organisms as the colon bacillus, various cocci, or tetanus, infection may be expected to result.

3. EFFECTS ON MOTORS

a. External

The erosive action of dust and sand on tires and rubber parts shortens the effective life of these articles from one-half to four-fifths.

Marked injury to vehicles can result when dust sticks to oiled bearing surfaces, such as springs and shackle, axles, bushings, and so on. United Nations troops have learned to guard constantly against this in such regions as North Africa and parts of India, and to take thorough counter-measures--especially in the case of vehicle parts which, by their constant close fit, insure long life, safety, or precision.

b. Internal

Even the most modern air filters fitted to automotive vehicles do not eliminate entirely the dust and grit particles in the intake air. The modern air-cleansing devices capable of delivering absolutely dust-free air to the engine would take up more space than is available under the average automobile hood.

Road dust has an abrasive action which causes serious and rapid wear on the pistons, rings, cylinder walls, and valve, mechanism, resulting in excessive oil and gasoline consumption.

United Nations personnel have found the following countermeasures effective when motor vehicles are operated in heavy dust:

(1) Frequent cleaning and flushing of air-filter elements;

(2) Elimination of dust, sand, and grit particles accumulated in the crankcase system by more frequent oil changes, accompanied by thorough flushing of the engine with a light-bodied oil;

(3) In the case of gasoline engines, the addition of an upper-cylinder lubricant to the gasoline;

(4) For chassis lubrication, the use of a substantial-bodied, stringy grease, with a high melting point, which will stay put even under very high temperatures.

4. EFFECTS ON OTHER EQUIPMENT

In dusty country, arms and weapons of all sorts, from the pistol to the artillery piece, wear out faster than elsewhere unless continually maintained. Cloth and leather are worn out by abrasion in one-tenth to one-fourth of the normal time.

5. EFFECTS ON OPERATIONS

Operations by mechanized units in heavy dust and sand storms may be compared with night operations. Direction-finding and identification are made difficult, but withdrawals are made easy. Artillery fire by direct laying is restricted because of the muzzle blast. The location of artillery observation posts requires extra consideration. Strategic moves often are made without disclosure, but close-in attacks by tank are generally considered unprofitable. Although infiltration by various types of units is possible, surprise can be double-edged, since the enemy may choose to follow similar tactics.

In heavy dust areas each vehicle moves in its own small dust storm. Surprise is impossible and offensive maneuver difficult. The artillery is hampered, especially in direct firing, and all vehicles generally move at increased distances apart and down wind from occupied points.

In any case, operations are slowed down considerably, not only because of low and intermittent visibility, but because of the time-out required for the maintenance, recovery, and repair of vehicles.