How the U-Boats Get Through the Nets 



They are equipped with remarkable motor-driven circular 

 knives and with steel flanges that spread out like doors 



FROM reports that reach 

 us from Europe we 

 learn that Germany 

 has equipped some of her U- 

 boats with ingenious devices 

 to enable them to cut their 

 way through submarine nets. 

 One boat with a double 

 flange of thin sheet steel pro- 

 truding from both sides of 

 the bow is said to have been 

 destroyed by shell fire and 

 .the device itself, practically 

 intact, is said to be in the 

 hands of the British Ad- 

 miralty. A second boat, 

 equipped with heavy motor- 

 driven circular knives at- 

 tached to steel hawsers, tor- 

 pedoed a merchantman, and 

 the captain, while in a small 

 boat, made a drawing of the 

 device for the Admiralty. 



The accompanying illustration gives a 

 clear idea of these net-cutters. The double 

 flange of thin sheet steel which protrudes 

 from both sides of the bow of the subma- 

 rine is, operated by electrically-controlled 

 gears. The flanges spread on either side 

 of the bow to a distance of eighteen feet, or 



Perspective >S»l 

 view of 

 double flange 



The double flanges of steel protruding from both sides 

 of the bow are operated by electrically-controlled gears 



The net-cutting device consists of heavy circular knives 

 attached to steel haws:rs extending from bow to stern 



thirty-six feet in all, whenever the nose of 

 the vessel touches an obstruction. Their 

 action is said to be automatic, although an 

 operator within the boat can extend or 

 withdraw the device at any time, by moving 

 two heavy metal arms. 



The U-boat equipped with the circular 

 knives is obviously far bet- 

 ter able to cut its way 

 through a net than the 

 boat j ust described . 1 1 does 

 not bother about a de- 

 vice at the bow, figuring, 

 no doubt, that the sharp 

 nose of the vessel and its 

 rounded hull are sufficient 

 to get through a net or stop 

 the boat before it becomes 

 entangled. . However, it 

 does not permit its con- 

 ning tower to go unpro- 

 tected. Several strands of 

 stout steel hawsers contain- 

 ing motor-driven knives, 

 a foot in diameter and 

 placed about a foot apart, 

 are stretched from the bow 

 through the conning tower 

 to the stern. Striking a 

 net, the knives would re- 

 volve on a flexible shaft. 



Plan, view of bow showing 

 flanges extended on 

 both sides 



395 



