Page:Popular Science Monthly Volume 91.djvu/179

 Popular Science Monthly

��Vol. 91

No. 2

��239 Fourth Avenue, New York City

August, 1917

��$1.50 Annually

��Drag-Bombing Submarines from Airplanes

��A new method of airplane attack

��CHAIN-DRIVE FROM ENGINE TO WIND, UP CABLE

CABLE

DRUM

SPROCKET

��IN the airplane the elusive submarine has a deadly enemy. Flying high above the surface of the ocean, an air- plane can see a submarine which has dived to avoid surface boats. The airplane's methods of attack have ' ot been so un- erring as the gun fire from the boats. But now comes Thomas E. Li ke, the son of the distinguished inventor of the Lake-type submarine, with a new method of airplane attack which looks as though the clearing of waters infested by submarines will be accomplished with far more ease in the future than it has been in the past.

Instead of using high speed airplanes to drop time-bombs on the sub- marines, Lake has de- vised a slower speed airplane for dragging contact bombs against it. His airplane, which uses a distributed wind-lifting area, is capable of high speed when scouting for sub- marines. But when it sights one, this airplane can slow up and can carefully go through its manuevers without losing buoyancy. The present-day naval airplane cannot do that; so that this marks the first advantage in the Lake method of attack.

The next, and even more important ad- vantage of the Lake attack is the manner of bombing. The submarine has little chance of escaping it. The slow-going air- plane nears the submarine broadside on. A heavy contact bomb is quickly lowered to the proper depth in the water by a spring-controlled mechanism.

This mechanism is an entirely new device which received its inception with the de- velopment of this plan of attack. It is very sensitive, for at the slightest reduction in

���the tension of the spring, the bomb re- sponds by sinking. It will continue to sink until the added upward thrust on the cable, caused by the water's pushing against the slanting wire which has just sunk beneath the sea, makes up the tension which has been lost from the spring. Therefore it is highly important to properly tighten this spring. In practice, this would be done by means of a turnbuckle which has been rigorously calibrated by factory tests. The air pilot lets the bcmb sink until it is just below what he gages the subma- rine's depth to be. The bomb thus drags along while the airplane approaches its prey nearer and nearer. Soon the airplane pass- es over the submarine. The wire dragging be- hind hits before long against the submarine hull. The bomb con- tinues on and swings toward the hull, the airplane drags it the short distance upward, and the bomb strikes the submarine. The percussion explodes the mine, and blows up the submarine without its having the least chance to endanger the airplane. Even should the bomb miss the submarine, it could be exploded from the airplane. The operator simply releases the brake for an instant, then presses down hard on the brake lever. The jerk will fire the emergency device within the bomb, and if the submarine is anywhere near it, the resulting explosion will disable the sub- marine, at the least. The ordinary method of dropping time-fused bombs on a subma- rine requires nothing short of extraordi- nary skill in aiming and timing the bomb so that its explosion will be effective. That method cannot be one-tenth as effective as this drag-bombing plan.

��;turnbuckle

��Details of the spring-controlled brake which keeps the cable taut and enables the bomb to sink to the proper depth

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