MARINE ENGINEERING

Evening Post, Volume CXI, Issue 76, 30 March 1926, Page 7

MARINE ENGINEERING

OPENING OF A NEW ERA.

A new era in marine engineering may be said to have opened in 1025, states "The Times." Probably, but for the Great War, the remarkable developments of last year and those now occurring would have taken place earlier. Shortly before 1914 efforts were being made to try to discover a satisfactory alternative to the reciprocating steam engine for ships, and steam turbines were being built on a considerable scale. Turbine engines have, however, not proved economical in every case, and, after the war, British firms, freed from some of their pressing anxieties, began to build motor ships each developing about 3500 horse-power, which was not sufficient for large passenger vessels. In the meantime Scandinavian owners, whose circumstances during the war period were so different from those of British owners, had built a number of experimental ships and were finding the results satisfactory. THE PIONEER AORANGI. It was not, however, until last year that large motor passenger ships began to make their appearance. The first Bhip of this class was a British vessel —the Aorangi—of 17,500 tons, which was built by the Fairfield Company on the Clyde for the service of the Union Steam Ship Company of New Zealand. The brake horse-power, at 14,000, was the.most powerful that had ever been provided in a ship, but it was given in the form of four engines each developing 3500 horse-power—a fact which itself indicated precaution, since the capabilities of each comparatively small engine were known. Incidentally, it is noteworthy that the engines were built under the license of the patents of theSulzer Company, of Winterthur, Switzerland. The favourable experience with this pioneer ship has promised much to encourage the construction of other large motor passenger liners. It was known that many owners would watch carefully the accounts of her performances. BRITISH AND FOREIGN VESSELS. The Gripsholm, a second motor passenger liner of similar gross tonnage, made her appearance at the end of the year. She was built for the trans-Atlantic service of the Swedish-American Line between Gothenbnrg and New York by Sir W. G. Armstrong, Whitworth and Co., on the Tyne, and the engines wero constructed by Messrs. Burmeister and Wain, of Copenhagen. The brake horse-power was 13,500, and it was provided by two engines only, as compared with the four of the Aorangi. The two engines of the Gripsholm wore the largest double-acting motors that had ever been bnilt for a ship. The experience of the vessel in service is reported to have been satisfactory, and it is understood that plans are now under discussion for tho construction of another : vessel of similar size for the same I owners. THE GREAT ASTTJRIAS. The next great motor passenger liner to be put into service will be tho Astnrias, of 22,500 tons, built by Harland and Wolff at Belfast, with two motors of the Burmeister and Wain double-acting four-cycle type, for the Royal Mail Steam Packet" Company's South American service. This vessel is to sail for the River Plate on 26th February, and she is to be followed by a similar vessel — the Alcantara. Messrs. Harland and Wolff are also building the Carnarvon Castle, of about the same size, which was launched early this month and is to be ready for the opening of the passenger season to South Africa in the autumn. Whilq, these large vessels are being completed in British yards, foreign builders are constructing passenger motor liners of large size. On 29th December the Saturnia, of 24,500 tons gross, was launched at Monfalcone, near Trieste, for the Cosulieh Line's regular service to South America. The two motor engines of the Saturnia and of the Urania, a sister ship, are to be of the Burmeister and Wain type double-acting four-stroke engines. The largest motorBhip yet designed ia also being built in Italy—namely, the Augustus, of over 30,000 tons, which is being constructed to the order of the Navigazione Generate Italiana. At present the motor engine is substantially more costly than the steam engine. Broadly, the cost of the motor is put at from 30 to 40 per cent, above that of a triple-expansion reciprocating steam engine of similar power. When the increased cost of the internal combustion engine is spread over the total cost of the ship the result is that a motor-ship may be said to cost, approximately, 15 to 20 per cent, more than a steam-ship, assuming that the hulls are of similar value.