The Future of the Large Marine Gas Engine.

Progress, Volume III, Issue 4, 1 February 1908, Page 130

The Future of the Large Marine Gas Engine.

The eminent marine engineer, F. E. Blgar, in^a papar recently read before the Engineering Conference at the Institute of Civil Engineers, I/mdon, dealt fully with this interesting subject, the most important part of which, perhaps, was an able recapitulation of the characteristics of efficiency, safety, and economy, which are indispensable if this type of engine is to succeed in the larger sphere so ardently desired by its advocates. He said : — 1 . The engine must be reversible. It must be capable of being quickly stopped and started, either ahead or astern. 3 It must be capable of being promptly accelerated to any speed between dead slow and full speed, and of being kept steadily at the required speed for any length of time. " Dead slow " ought not to be faster than onequarter of full speed, and should be less in very fast vessels. 4. It must be capable of running continuously for long distances, with but short intervals between the runs, without risk of stoppage and breakdown. 5 It must be capable of working well in rough as well as smooth water, or in seaway in which the variable immersion of the propeller causes fluctuating resistance. 6. All working parts must be readily accessible for overhauling, and all working parts must be capable of being promptly and easily adjusted. 7. The engine must be economical in fuel, especially at its ordinary working speed. 8. It must be compact, light in weight, and well balanced, so as not to cause vibration. 9. It must not involve an\ risk of accumulation of gas in the ship, such as to form an explosive mixture. 10. Above all it must be capable of using a fuel whose supply at a moderate price is practically unlimited, and can be readily obtained in any part of the world a ship might visit. Referring to published plans for installing gss and oil machinery in 16,000-tou battleships, Mr. Elgar maintains that " this exists at piesent in imagination only." "It is impossible " he continues "for any one to judge by what has been achieved up to the present in this direction, what weight cr space or what consumption of fuel would be required for the internal combustion engines of great power, that might, perhaps, ultimately be made to fulfil tbe onerous requirements oi marine work. Engineers and metallurgists may by working together succeed some day in overcoming the difficulties of producing large cylinders which will stand the high impulses and great and rapid vibrations of temperature that occur with internal combustion, but until this is accomplished no great step ahead has been taken." On this the Iron Age remarks — There are those who will be inclined to consider this view extreme. Many installations of large internal combustion engines have been successful ashore. It is natural to be credulous that in the future engineers may solve the problems of any new branch of engineering. ' Many times in the past a few years have sufficed to contradict the most distinguished disbelievers. Another paper read at the conference told of the progress made with the marine steam turbine, which has grown in its application from the tiny Turbinia of 1894, to the gigantic Lusitania and Dreadnought of to-day. A

curve' showing the total horse-power of steam turbines applied to marine propulsion has its beginning at zero in 1896, and its end at 390,000 horse-power in 1906. It is doubtful if many engineers at tjie advent of the Tmbinia expected a turbine -propelled Lusitamo within 10 years. Repeated instances of the sort have bred a confidence in the world's engineering genius, that warrants hope for great ships propelled by combustion engines in the comparatively near future, and cheaply, perhaps with crude oil, perhaps with alcohol or other clean fuel. Yet Mr. Elgar's list of qualifications that the engine must possess is by no means unreasonable. It would be difficult to eliminate one of them. Some of the problems have not been nearly worked out in their application in a large sense, and others will require a good deal of advancement before they are completely solved, even for small powers. In large ships the engines must be as safe and sure and economical as the reciprocating engine or the turbine. The large power unit installed on unyielding, immovable foundations in a stationary power plant is surrounded by very difficult problems from those the marine engineer must face in applying the same type of engine to a large vessel. His difficulties are fully as great as those encountered in the development of the steam engines and perhaps they are greater, because of the nature of the fuel and of its application to the engine. Great progress has been made with the marine combustion engine, but few will dispute that it is still in comparative infancy. The question is, how soon will it reach the maturity of an accepted type of engine for large ships.?