228 



Popnlar Science Monthly 



To attain that buoyancy is the chief 

 problem of the designer of a cargo- 

 carrying submarine. Let us see how 

 Mr. Lalce has solved this problem. 



Study the accompanying drawings 

 and you will notice that Mr. Lake's 

 blockade runner consists of an outer 

 hull and an inner hull. The outer hull 

 resembles that of the ordinary surface 

 vessel in all essentials. The inner hull is 



submerged. When the vessel is to rise, 

 the sea water is pumped out. When the 

 vessel is submerged, the cargo-carr^•ing 

 tanks are entirely surrounded by water. 

 The inner hull is pressure-resisting, the 

 outer hull, non-pressure-resisting. The 

 water-tight cargo tanks are obviously 

 set in compartments which may be re- 

 garded as water-ballast compartments. 

 These are filled during submergence and 



A Submarine Blockade Runner Which Could 



Newspapers have had much to say of a mysterious German 

 cargo-carrying submarine which will run the British blockade 

 and which will bring to New York coal-tar dyes and chemicals, 

 some of which are worth as much as $100 an ounce. The 

 difficulty of obtaining suitable engines has not been con- 

 sidered in these accounts. But the designing of a boat, apart 

 from the provision of adequate motive power, is not hopelessly 

 difficult. Simon Lake, one of the foremost American inventors 

 and builders of submarines, has patented the design here 

 shown. The cargo is stowed away in air-tight and water- 



a long cylinder divitled into compart- 

 ments to provide sleeping quarters, a 

 mess room, a na\igating cabin, a galley, 

 an engine room and the like. The 

 cylindrical inner hull is air-tight and 

 water-tight. 



The cargo is disposed in vertical tanks 

 l)etwccn the outer and inner hulls. The 

 cargo tanks are air-tight and water-tight 

 and are filled from the top. Air-tiglu 

 and water-tight closures are provided. 



Tile spaces formed between the outer 

 hull and the inner hull arc to be filled 

 with sea water wiieii the vessel is to be 



arc emptied when desired b>- means of 

 compressed air which is blown from bot- 

 tles located in the lower jiart of the hold. 

 As the water is ejectetl, the space will be 

 replaced by air of such pressure as to 

 ecjualize the external pressure and thus 

 l>revent the collapse of the outer hull. 

 Indeed water is freely used so that tho 

 outcr non-resisting hull ma>- stand up. 

 ,'\bo\-e the superstructure will be 

 noticed a glass coaming. This is about 

 six feet high and ser\-es to prexent the 

 wash of the waves from obscining tiio 

 l)eriscope. 



