Abstract
The methods of reversing as originally adopted in the German design for two-cycle engines and the method developed by an American firm for four-cycle engines, are discussed. A modification introduced in a two-cycle slow-speed engine used in a submarine tender proved satisfactory.
Diesel engines are usually started by means of compressed air; in small marine engines, a clutch between the engine and the propeller permits the independent starting of the engine. In all cases a smooth start is secured by bringing first the temperature in the cylinders to approximately the same value it has under working conditions. Regular turning moment and definite ignitions in the cylinders make possible the successful operation of a Diesel engine at slow speed. In the large sizes a smooth running at low speeds with light loads is obtained by a mechanism controlling the lift and timing of the spray valve.
While lubrication by gravity is used successfully in large open-frame slow-speed engines, the increasing adoption of forced lubrication in engines of all types and sizes is an evidence of the superior advantages of the latter system.
The satisfactory results given by the 2500-hp. six-cylinder two-cycle Diesel engines of the U. S. S. “Maumee” point out that all ocean-going cargo vessels can be equipped with Diesel engines.
Several features of the fuel system, the arrangement of the exhaust piping, the varieties of muffler, and the systems of cooling the various parts of Diesel engines, are considered from the point of view of the author’s experience.
