Torpedo-Boat Destroyer

Collier's New Encyclopedia (1921)

a torpedo boat of a most formidable kind, designed for the destruction of ordinary torpedo boats. The destroyers are usually armed with one 12-pounder gun and from three to five 6-pounder guns, besides their equipment of torpedoes, and carry a crew of four officers and about 40 men. They are capable of 30 knots an hour, and, as they carry from 70 to 100 tons of coal, can make a voyage of 1,300 to 1,500 miles without recoaling. The World War introduced many improvements in destroyers. They performed invaluable services in naval operations. In the battle of Jutland the German destroyers raised a smoke-screen before the German fleet, which enabled the German admiral to withdraw his ships from immediate danger from British guns. See TORPEDO BOATS. TORPEDOES. The torpedoes known to modern warfare are all automobile; that is to say, they run by their own power, differing in this respect from projectiles fired from guns, which otherwise they rather closely resemble. And not only do they run by their own power, but they carry a complicated mechanism by which they steer themselves, regulate the depth at which they run, and render certain themselves harmless after a length of time if they fail to hit their mark. Torpedoes of various forms have been known and used for several centuries, but the automobile torpedo of today is essentially a development of the last fifty years, having been invented about 1870 by an Englishman, Whitehead, who, failing to secure recognition from the British naval authorities, took his invention to Austria, where it was at once adopted. It was slow in making its way in other countries, and even as late as the beginning of the World War, in 1914, was regarded in many quarters as of no great practical value. It accomplished nothing in the Spanish-American War of 1898 and little or nothing in the Russo-Japanese War of 1904; and even those who had most faith in its possibilities were unprepared for the manifestation of its efficiency given by the Germans in the first months of the World War and thereafter. A large part of this efficiency was due, of course, to the remarkable development of the submarine, a development which at that time had been carried much farther in Germany than elsewhere. But the outstanding feature of the submarine campaign was the thoroughness with which the two factorsthe torpedo and submarine had been adapted to each other. Both the British and the American navies took the lessons of the war to heart and both have now, a little late, carried both the torpedo and the submarine far beyond the point attained by the German navy at its best. Figure 1 shows the principal features of the torpedo. At the forward end is the war-head, A, carrying the explosive charge, 600 pounds of gun-cotton or trinitro-toluol. The fuse by which the charge is exploded on striking projects from the nose of the war-head but is rendered inactive until the torpedo is fired by a safety device which is released by pressure of the water. For purposes of drill the war-head is replaced by an exercise-head made of soft metal which collapses when it strikes a hard surface, thus indicating that the target, often the side of a friendly battleship, has been hit. Immediately abaft the head is the aira large compartment charged flask, B, B, with air under high pressure and furnishing the motive power for the engine, D. In a pipe leading from the air-flask to the engine is the starting-valve, connected with a small lever on the outside of the torpedo which is tripped automatically when the torpedo is fired. The engine in the latest American torpedo is a turbine, but reciprocating engines are still used abroad. The shaft runs through the after-body, E, to the propellers, of which there are two, RR, in tandem, one being keyed to the shaft and the other to a sleeve around the shaft and connected with it by a beveled gear. The propellers turn in opposite directions, one right, the other left, and must be balanced perfectly, as the slightest difference in their action would cause the torpedo to diverge from its initial course and might make it run in a circle and, in an extreme case, strike the ship from which it had been fired. The rudder, R, abaft the propellers, is placed horizontally, not vertically, its AIR FLASK A B B XC WAR HEAD DIAGRAM OF TORPEDO-FIG. 1 purpose being to steer the torpedo up and down, not to right and left. Very small vertical rudders are used in connection with the Gyro gear, described later, but these are not shown in the drawing. The brains of the torpedo are in the immersion-chamber, C, between the airflask and the engine compartment. Here is placed the mechanism by which the torpedo is governed in many ways. A gyroscopic device opposes any tendency to deviate from the initial course. A depth-regulator insures running at a pre-curacy enormously reduced when both scribed depth, usually from 15 to 20 feet. plug opens a valve after a A soluble ble certain time and causes the torpedo to sink if it has missed its mark. An automatic throttle-valve keeps the air pressure constant during the discharge of the air-flask, insuring a uniform speed throughout the run. Of these devices, only the depth-regulator, Figure 2, will be described, this being, perhaps, the most characteristic feature of the torpedo. The essential feature of this device is the utilization of the pressure of the water, which varies with every variation in the depth, to actuate the horizontal rudder already described and so steer the torpedo up or down, as may be necessary. The figure shows the immersionchamber (water-tight), and the engine compartment (open to the sea), separated by a water-tight bulkhead. In the immersion-chamber is a sleeve carrying the hydrostatic-piston, which is held by a spring in contact with a flexible diaphragm forming a part of the watertight bulkhead. The tension of the spring can be varied to correspond with the pressure of the water for any desired depth. If we suppose the spring to be given a tension equal to that of the water at a depth of 15 feet, the piston will is runremain at rest when the torpedo bedo edo ning at that depth. If the torpedo rises, the pressure of the water on the flexible diaphragm will be less than the tension of the spring and the piston will move to the right, carrying with it a rod which is attached to the rudder, and steering IMMERSION RUDDER CHAMBER AFTER BODY a R E D R ENGINE a PROPELLERS COMPARTMENT the torpedo down. If it dives too deep, the balance of pressure is disturbed in the opposite direction and the torpedo is steered up. And so on, until the torpedo becomes steady at the depth for which the spring is adjusted. The range of the most powerful torpedoes in use in 1921 is approximately 12,000 yards (six miles) and at this range a stationary target of the length of a dreadnaught can be struck three times out of four. Naturally the conditions are greatly modified and the acthe firing ship and the target ship are moving at considerable speed. The ships sunk by German torpedoes during the war were all attacked at short range, usually less than a thousand yards. While torpedoes may be launched from battleships, all of which are fitted with elaborate arrangements for the purpose, they are more effectively fired from smaller craft-destroyers and submarinesthe high speed of the destroyer and the invisibility of the submarine giving such a craft a great advantage in the use of a weapon like the torpedo, which is essentially a weapon of surprise. One of the developments promised for the future is a torpedo airplane, which shall carry a torpedo, with arrangements for launching it from a height of several thousand feet while flying at full speed. There is promise also of a torpedo which can be controlled from the firing ship or from a shore station, by radio. Lastly may be mentioned a possible combination of these two plans, the torpedo being IMMERSION CHAMBER (WATER-TIGHT) PISTON GUIDE SLEEVE SPRING CONNECTS WITH STEERING GEAR DIAGRAM OF DEPTH launched from an airplane at a great distance from the target, and controlled by radio from the airplane and so guided directly to the mark.