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 



163 



