Page:Popular Science Monthly Volume 89.djvu/242

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��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.

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