The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

June, 1909 Tac. Marine REVIEW Combinationof Reciprocating and Turbine Marine Machinery HE White Star liner Laurentic, which left on. her first 'voyage to Canada .dur- ine thé latter part. of April; is of special interest as the first Atlantic liner fitted with a combination of reciprocating and turbine machinery. She is notable also from other points of view: she inaugurates the White Star service to the Dominion, and, in view of the great potentialities of our western colony, and of the repute of the White Star company, there can be no question as to the advantage and success .of this ad- new public rooms, is the adequacy of ventilation by electrically-driven fans. But, from the scientific point of view, interest centers in the machin- ery. The White Star Line has ever been noted for its enterprise, and has found in Messrs. Harland and Wolff, of Belfast, able and willing coadjutors in the introduction of improvements and invention. It is not necessary now to recall the great departures in marine construction which were originated by the late Sir Edward Harland: dnd. the late Mr- 7. i. Ismay in the early and _ succeeding 199 to a low absolute pressure corres- ponding to the highest vacuum ob- tainable in turbine practice. While it is too early to speak with. confidence as to the measure of economy ob- tainable under service conditions in the Laurentic, the full-power trials, although short in duration, gave re- sults which confirm those achieved in two other vessels having the same combination' of 'machinery--the New Zealand liner Otaki, built by Messrs. Denny, of Dumbarton, and the yacht Emerald, engined by the Parsons com- pany. The water consumption for the main engines was appreciably under 13. Ibs. per horsepower per hoyr, while in Atlantic liners with triple- rarely expansion engines the rate is ditional Empire line. The Laurentic too, is larger than any other ship in the Canadian service; her length is 565 ft..6 in. over all; beam, 67 ft. 3 i.; and depth, moulded, 45 ft. 6 in.; the registered' tonnage being about 15,000 tons, and the displacement at service draught about 20,000 tons. Everything has been done to insure the safety and comfort of the 260 first class, 430 second, and 1,000 third class passengers to be carried; the decorations are in good taste, the wood, mostly oak, being finished in ts natural color, and special care has been exercised in the selection of fine-grained panels and pilasters. The State rooms are in white enamel; and one feature in these, as in the Tue Wuite Star CANADIAN LINER White Star liners, and it is gratifying to have the further evidence afforded by the Laurentic of the maintenance of traditional progress by their suc- cessors, Lord Pirrie and Mr. J. Bruce Ismay. The Laurentic has, as sister ship, the Megantic, differing only in the machinery, and thus there will soon be available accurate comparative data of the performances of the two different types of machinery. As is well known, the idea of the combina- tion is to utilize in the turbine the remaining heat energy in the exhaust steam from reciprocating engines, which, as a rule, is not less than 10 lb. pressure' absolute. With -- the Parsons steam turbine it is possible. to expand this low-pressure steam LAURENTIC. under 16 lbs. With a rate of evap- oration in the boilers of 8 lbs. per pound of Welsh coal, or slightly less with the more largely used Yorkshire coal, the financial gain is considerable, for not only is the coal bill reduced, but the increase in cargo capacity due to smaller boilers and bunkers, is also a consideration in the balance sheet. It is true that the weight of engines and space occupied are great- er when the turbine supplements re- ciprocating engines; but the reduction in steam consumption justifies less boiler power, and thus on a balance the weight may be about the same. Moreover, the system is specially ap- plicable to vessels of less than 18 knots speed, in which neither weight