The Submarine Torpedo Boat
Its Characteristics And Modern Development

176 THE SUBMARINE TORPEDO BOAT the present automobile torpedo, with its speed of thirty- five knots and its 4000 yard range. There are several makes of torpedoes on the market at the present time, all of them having practically the same characteristics and construction. The torpedo itself is divided into sections. The forward one contains the ex- plosive charge and the firing pin. When the head of the torpedo strikes a ship or any other rigid object the firing pin or plunger is driven against a percussion cap containing fulminate of mercury and situated in the center of the bursting charge. The explosion of this cap detonates the high explosive contained in the chamber with sufficient force to rupture the plating of any battleship and in all probability to cause her magazines to explode. In order that no accident might occur the firing pin is normally held away from the percussion cap by a spring and a lock device consisting of a collar which is fixed to the pin outside the nose of the torpedo. This collar is fitted with pitched blades which cause it to revolve when passing through the water and thus releases the firing pin from its restraining action after running twenty-five or thirty yards upon its course. For practice firing the above described loaded war head is substituted by a collapsible dummy head. This dummy head has the same weight and appearance of the war head but is made of thin soft metal so that it collapses on strik- ing and thus proves a hit. It contains no explosive. The section immediately abaft the head is the air flask, which is charged with air compressed to about 2200 pounds per square inch. The mechanical energy con- tained in the compressed air serves to drive the torpedo. Ihe tank will hold enough air to drive the torpedo 4000