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eS Yacht Southwark, First to be Driven by Southwark-Harris Crude Oil Engine, Performs Creditably on Trial Trip—Details of Engine and Its Operation HE FIRST. formal trial trip of the yacht SouTHwarK on June 26, in the Delaware river, was of great interest to the marine field gen- erally, since the craft is the first to be equipped with an engine of the new Southwark-Harris type. The perform- ance of this prime mover, which oper- ates on the diesel principle, indicates it has a wide range of usefulness for propelling vessels of various kinds and sizes. SouTHWARK, which is owned by C. P. Vauclain, Phila- delphia, is 98 feet long with 16-foot beam and 7-foot draft. Her pro- peller, which is driven at the rate of 300 revolutions per minute, is 50 inches in diameter and has a pitch of 56 inches. Her Southwark—Harris engine has four cylinders, the in- dicated horse- power being 240 and the brake horsepower, 150. The weight of the engine, including flywheels, is 24,- 000 pounds. Dur- ing the cruise, the yacht easily main- tained a speed of 12 miles per hour; it proved directly re- versible from full speed ahead to full speed astern within five seconds, the en- gine in all cases starting and reversing under full load. The engine developed full power within 10 seconds of starting from stone cold. It operated on fuel oil costing 2%4 cents per gallon, the consumption being at the rate of 7% gallons per hour. As is well known, a diesel type en- gine comprises certain essential parts, including a scavenging pump or low pressure compressor, a main or work- ing cylinder and piston, an atomizer, a fuel pump and a multi-stage air com- pressor. In brief, an ordinary two- cycle diesel engine operates as fol- lows: the fuel pump places a small quantity of crude or fuel oil in the atomizer at a certain instant in the revolution of the engine and leaves it there. The scavenging pump blows the gases of combustion out of the cylinder and into the exhaust pipe, and leaves a charge of pure air in their place. The piston returns in the cylinder and com- presses this charge of pure air to a pressure of approximately 500 pounds per square inch, at which pressure the air has a temperature of about 1,000 degrees Fahr., which is sufficient to ignite almost any kind of oil in atomized form. Next, the atomizer spindle is lifted by a cam shaft and the charge of FIG, 1—YACHT SOUTHWARK, FIRST CRAFT TO BE EQUIPPED WITH A SOUTHWARK HARRIS ENGINE oil, in the form of a spray, is forced from the atomizer into the hot com- pressed air. The ~ oil | immediately ignites, further heating the charge of air and causing it to expand behind the piston and thus to transmit power to the crank shaft. Embodies Novel Features These essential parts, and this se- quence of operations, are found in the Southwark-Harris engine, which, how- ever, embodies further features, novel in diesel engine design, which, it is claimed, simplify both the construction and operation, as! well as increase the operating efficiency of the engine. The feature of chief interest is the scaveng- ing pump, which, in addition to scaveng- ing, performs other functions. This pump is of the step piston type, that 1s, the piston of the scavenging pump is 343 By E. C. Kreutzberg an enlarged extension of the main pis- ton, working in its own cylinder below the working cylinder. The normal function of the step pis- ton is to draw in a charge of fresh air on each downward stroke and, on the upward stroke, deliver it to the adjacent working cylinder through a manifold. The cylinders, of course, are arranged in pairs, the step-piston of each scavenging the working cylinder of the other. In addition, the step-piston is employed for starting or reversing the: engine on air. On moving the starting lever, either ahead or astern, each scavenging cylin- der immediately is converted into an air motor; the suction and _ de- livery valves are cut out auto- matically, the air starting valves automatically open and compressed air: enters . the cylinder and oper- ates the step pis- ton. On continu- ing the movement of the _ starting lever, the atomiz- ers supply fuel to the working cylinders, and thus the engine begins operating on fuel. At this in- stant in the cycle of operations, there- fore, the engine is being operated both by oil and by compressed airs tes ‘customary, after starting, to operate the engine on fuel oil only, although, if desired, the power may be augmented ‘by consuming both compressed air’ and ‘oil at the same time. While operat- ing as an air motor, the step piston, on its return “strokes, continues to fulfill its function of a scavenging “pump. In ordinary diesel type engines, air at high pressure -is admitted into the hot working cylinders for starting or ‘reversing, this air being stored in bottles or tanks at a pressure of 800 to 1,000 pounds per square inch for two- cycle engines, or 300 to 800 pounds per square inch for four-cycle engines. Air, at these pressures, when expanded