Fig. 99.—Smoke Screen for Tanks.
Screening Tanks
Tests have demonstrated ([see Fig. 99]) that successful smoke screens for tanks may be produced by spraying oleum into the exhaust. On a 7-ton tank of the Renault type (40 H. P.) 110 cc. per minute produced a large volume of smoke, which had excellent covering power, and which could be made intermittent or continuous at will.
The same method may be applied to aeroplanes, and to ships. It is calculated that a cylinder containing 300 pounds of 20 per cent oleum will maintain a smoke screen on a ship for a period of 15 minutes, if oleum is used at the rate of 23.6 pounds per minute. Since the cylinders may be arranged in batteries, the screen may be continued for any period of time. The Tank Corps rather favor phosphorus rifle grenades for producing a smoke screen at a distance from the tank.
Purpose of Smoke Screen
Smoke screens may be employed with one or more of the following objects in view:
(1) To mask known enemy observation posts and machine gun nests; to conceal the front and flanks of attacking troops, concentration of guns and tanks, roads and concentration points; to blind the flashes of batteries in action and to hamper aerial observations.
(2) As a feint to draw the enemy’s attention to a front on which no attack is being made, so as to hold his troops to their trenches, or to induce him to expend ammunition needlessly and to put down a barrage in the wrong place.
(3) To simulate gas and force the enemy to wear his mask. Gas should occasionally be mixed with smoke, to impress upon him the belief that it is never safe to remain in a smoke cloud without wearing his mask.
(4) In rolling or mountainous country, to fill valleys with smoke and thereby conceal the advance from all observation, including aerial.