MOTORS IN WARFARE. The various motors employed in military aeronautics, cul minating in the "Liberty motor," and the various motor trucks produced under specifications ap proved by the War Department Motor Trans port Board are so constructed that the various units entering into the construction, including the engine, transmission, axes, springs, univer sal joints, frame, radiator and fan, are inter changeable as far as possible. This interchange ability of parts led quickly to the standardiza tion requirements of the government which put an end to the complicated engineering, purchas ing and manufacturing problems, to say nothing of the enormous cost of the finished product, due to lack of uniform manufacturing limits and patterns.
The Liberty airplane engine and the war trucks are not examples of standardization in the commercial sense, but of military designs dictated by war needs. The standardization by the government of the necessary designs of all kinds of self-propelled vehicles operable on land, sea or in the air, is one of the chief factors in determining the outcome of war. Likewise the submarine problem may possibly be solved by the adoption of one of the designs of large sea planes recently perfected. The seaplane is not the only type of craft for marine use in attack ing the submarine. The so-called submarine chaser is another recent war product. The de signs and construction of motors used in many of these submarine chasers constitute some of the most important problems of automotive en gineers. The production of the boats by stand ardized processes has been a great achieve ment. The development of small stationary or semi-portable units for the operation of the wireless set, the searchlight, pumps, isolated electric lighting plants and machine tools in portable repair shops, is another of the matters handled by automotive engineers. These ma chines perform highly important functions in the great military organizations of modern times and those responsible for their design and oper ation deserve equal credit with those who have contributed to the more spectacular forms of modern warfare. The United States standard army truck is not a commercial 3-ton truck, hut an excellent 5-tonner and its engine axles and transmission is commonly used for 5-ton as sembled trucks. Its outstanding characteristics are exceptional power; good springing, making the riding almost as good as that on a passenger car; reasonable economy of fuel; ability to handle cold air and poor fuel without the least difficulty in starting and ease of steering and control. The complete truck with body, top,
and equipment weighs a trifle over 10,000 pounds, and the chassis with driver's seat and in running condition scales 8,600 pounds. The engines have detachable heads and complete pressure lubrication is used. The following is a summary of principal points: (1) the engine has four 4 by 6 cylinders, cast in pairs, with detachable heads; (2) much attention has been paid to the cooling and lubrication problems; (3) force-feed lubrication is used throughout and the oil is doubly strained; (4) two entirely separate ignition systems, one battery, the other magneto, are used; (5) the crankcase, including the bell housing and the oil pan, is aluminum, three-point support being used; (6) the crank shaft is very rugged, and is notable for its large intermediate bearing, as long as the rear one; (7) the governor is the steel-ball type, and so enclosed and sealed that it cannot be tam pered with; (8) there is a dry disc clutch, a four-speed horizontally arranged change gear, a work drive, a full floating rear axle and Hotch kiss drive.
There are two methods of transporting heavy artillery; one to pull the piece; the other, to carry it in one or two loads. Both have their advantages and disadvantages. It is naturally easier to pull the gun than to load it on the truck, but the pulling of the gun on the road behind a truck results in considerable wear and tear on the pieces. To reduce the latter, truck pulling pieces do not go faster than from seven to eight kilometers per hour, and a great deal of care is taken to prevent injury to the recoil apparatus of the gun by collision, etc. Carry ing the gun has the great advantage of permit ting the truck to make from 10 to 15 kilometers speed. It is necessary to differentiate between these methods of movement and the movement of heavy tractor artillery. This latter artillery is actually formed in requirements and groups and includes all the necessary tractors and trucks for its complete unit and for the first supply of ammunition. The tractors of the group are all of the 4-wheel driven type instead of the 2-rear wheel driven, as is the case with all other tractors.