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46 THE MARINE REVIEW February, 1912 Diesel Engines 'Their Advantages By: Sic J: Fortescue Flannery O IMPROVEMENT | of the first mag- nitude in marine construction has been so long heralded and so late in general realization as the ap- plication of the in- ternal combustion engine to big ships. The internal-combustion engine driving motor cars and motor launches is now so familiar as scarcely to awaken ob- servation or comment. These engines are always of small power and nearly 'always of the type in which the ex- plosive mixture of atmosphere and petrol vapor is ignited by an electric spark. It was Mr. Diesel who proposed to ignite the explosive mixture by the heat of the air compressed in the cylinder before the admission of the petroleum, so that the formation of the mixture and its explosion should ' be nearly simultaneous, and the loss es due to admixture in a_ separate chamber or carbureter, and the use of a separate dynamo or accumulator with wires and sparking plugs might be avoided, whilst their complica- tion and risk of breakdown would also be eliminated. . Use of Crude Oil. The high temperature at which the petroleum and atmosphere come to- gether in the compression stage of the Diesel engine also facilitates the use of petroleum in a form less vol- atile than ordinary petroleum spirit, and, indeed, in some cases crude or even the residue of petroleum left after taking off the spirit and inter- mediate oils has been usable in the Diesel engine from this cause. There is a large production of residuum from the refineries.of the oilfields, and the full solution of the problem of using it in marine engines is attract- ive alike to oil producers, to marine engineers, and to ship owners. It is attractive to oil producers because it would give them an extended mar- ket where the economical result is multiplied by the saving of weight in comparison with other fuels. It _is attractive to marine engineers be- cause the saving of weight in propor- tion to the power developed is very great as compared with the weight. of steam engine and boiler combined, and it is attractive to the ship owner because the saving of weight and space, both in the machinery itself . and still more in this fuel as com- pared with coal, would add greatly to the freight-earning power of ships, whether computed by weight or meas- ufement. And yet the fate of the Diesel engine seems to have hung in the balance for three years or more, although it has been discussed and considered and piously approved by nearly everyone connected with ship construction and management. Forgotten Difficulties. | The difficulties that first attended the use of liquid fuel at sea, in the form of a steam boiler combustible, are now almost forgotten, and today the economies claimed by Sir Mar- cus Samuel, who pioneered the ues of liquid fired steam boilers, are real- ized as a matter of course, easily and without doubt, experiment or anxiety. These economies are chiefly a reduc- tion of 35 per cent in the weight of the fuel as compared with coal, a still greater increase in the storage room transferred from bunker space to cargo space, a reduction in the stokehold crew, and greater facility and less demurrage whilst bunkering. The drawback to the more general adoption of liquid fuel as a steam raiser at sea appears to be, for the navy, the question of international supply, and for the mercantile marine the margin of freight compared with the price of liquid fuel. on the threshold of improvements in the combustion of liquid fuel by which, using it direct in the engine and eliminating the economic loss due to intermediate steam raising, we can obtain largely increased power in pro- portion to weight of fuel, then the margin "between price of fuel and rate of cargo freight will be so broadened 'that ship owners can bet- ter afford to pay the comparatively high price which liquid fuel must always command relatively to coal, especially in the western hemisphere, where coal requires little and petrol- eum a great deal of transport from If we are' its place of origin, That this in- crease in probable future economic result may 'be great will be seen when it is stated that 1 ton of liquid fuel under a steam boiler will do the work of 1% tons of coal used as a steam raiser, but that 1 ton of liquid fuel in an internal combustion engine will do the work of nearly 4 tons of coal under a steam boiler. The weight of the Diesel engine, with its air-compressors and other gear, is less than two-thirds the weight of steam engines and boilers of the same power. We have seen, therefore, that the inducement to use liquid fuel is un- doubted, even when the economy is estimated upon the results already attained in the limited experience for long sea voyages that has so far been made public. Why, then, is the prog- ress so slow, and more especially slow in Great Britain as compared with the Continent, although British ship owners have very freely and _very generally expressed their readi- ness to act on the new improvement, and oil producers have expressed their readiness to enter into contracts for terms of years long enough to provide every reasonable safeguard. Caution of Marine Engineers. The answer is to be found in the caution--perhaps undue caution -- of the great body of our marine engi- neers. It is true that Messrs. Vickers have fitted submarines with successful Diesel engines, that Messrs. Swan, Hunter and Wigham Richardson built the Toiler nearly two years ago, fit- ted with oil engines, and that Messrs. Richardsons, Westgarth are building a Diesel engine cargo boat, and that Messrs. Doxford have one unit of a Diesel engine experimentally under construction, and that Messrs. Bar- clay Curle are building a large ves- sel on Continental account with Die- sel engines of good power which will be ready for trial trip in February next. It is also true that my own firm have been responsible as con- sultants for sending to almost every one of our Colonial possessions many petrol and paraffine engines driving launches and tugs of medium size, but it is in Russia that a fleet of