MARVELS OF MODERN STEAMSHIP ENGINES.

Lake Wakatip Mail, Issue 2663, 9 June 1908, Page 7

MARVELS OF MODERN STEAMSHIP ENGINES.

WHAT A TURBINE REALLY IS

AND HOW IT WORKS

There is one very striking fact which has doubtless impressed itself uron the minrfs of those who have

(Mowed the extraordinary development of Atlantic liners during the , last ten or twenty years. Not only are we building floating leviathv'ans to-day which are nearly three times as heavy and almost 200 ft. longer than the biggest Atlantic liner of ten or tvrlve years ago. but these mammoth vessels attain a far greater speed than their smaller rivals. When, in 1900, the Hamburg-Ame-rican liner IVMitschland, a vessel fi6oft. in length, whose gross tonnage is 16,"»O0, earned for itself the distinction oi being the fastest steamship in the world by maintaining a of 23} knots per hour—which is equal to 27 miles on land—someone said it was the last word in quick sea travelling. But. as everyone knows, the Lvsitaiua. the mammoth Cunarder. which is almost twice as heavy and 125 ft. longer than the Peutschland. has proved that it was a bad prophecy by showing herself quite capable of maintaining her contract speed of 2."> knots (nearly 29 ini'cs) so hour. F»\en that, however, is*not the Lusitania's limit ; but it is quite sufficient for the Admiralty, who have subsidised her building, as well as that of her sister ship. Mauretai ia. both of which will be available- as armed cruisers or scouts if required by the Government. The speed attained by the Lusitanin. and the 31 miles accomplished the other day by the Mauretania. are not only a triumph for the Cunard line, but also a huge success for the Hon. C. A. Parsons, the famous < ngineer.who has developed the steam turbine to that degree of efficiency which has enabled these floating cities to travel through the water at such a s:>eed. Until the advent of. the turbine, the shaft of a liner's propeller was always rotated by driving a piston backwards and forwards throrgh a steam cylinder on the exact lines of the ordinary steamenpine. In the turbine we have a cv Under, but insteail of the steam driving the pis!on rod. which in turn rotates the shaft of the propeller, it arts in a more direct manner upon a higc drum fixed to the shaft. On th.< outside of this drum, and affix-Hl to the inner surface of the cylinder in which it revolves, are in the case of the Lmitania. 1.300,000 projecting hollow-fated blades or Minis, the longest being 22in. and 1J in. wide. The fixed blades on the cylinder are ilar.ted slightly in an opposite direction to those which revolve with the drum. Between these two sets of blades the steam is sent with terrific force. The fixed blades, acting as a sort of guide to Ihe steam, pass it to the blades on the drum, and it is the millions of microscopic atoms of steam, which fly like so many bullets against the sloping blades, which cause the drum to revohe.

The Lusitania. being propelled by four turbine screws, has. of course, four turbine motors in her engineroom, and the combined push of all the blades amounts to the 68.000 horse-power which is necessary to drive the ship at 25 knots. The rotating mass in the engine-room weighs 600 tons, and revolves at about 200 revolution* a minute. K very thing depends upon the proper "set" and inclination of the two sets of blades, which, if correctly placed, BiK tip the last ounce of energy of the steam in its passage through the turbine. Altogether 1.000 tons of coa< are burnt daily by the Lusitania to obtain her 25-knot speed, and the quantity of coal consumed on a trip to New York would keep the fires of 3,000 wording men's houses going for a year. No fewer than 250 firemen and trimmers are required to sto!-e the 192 furnaces in the ship, while the brass and steel, tubes on the boilers and condensers are 144 miles in length and weight 600 tons. The adoption of the turbine means not only increased speed to the san>3 boiler-power, but also less cost of upkeep, a smaller engine-room staff, and a diminished bill of lubricants, furthermore, there is none of that vibrating which is so irritating to passengers on vessels driven in the ordinary way, while the smaller en-gine-room ensures more commodious quarters and promenade space. Mr. Parsons first demonstrated the suitability of the turbine for the propulsian of steamships by building the Turbina. a vessel of the dimensions of a torpedo-boat, which in 1897 achieved the then unprecedented, speed of 32? knots (nearly 38 miles) on a measured mile. A still more remarkable i>erforroaiicc was that of the torpedo-boat destroyer, the Viper, which, with turbine engines of about 10.000 horse-i>ower, reached a speed of 35J knots, or nearly 41 miles ar" hour.

Even more remarkable, however, is the power claimed for a turbine engine invented by a Glasgow engineer, which, although little more than a foot in diameter, is capable of developing -lo horse-power. It is said that this invention will revolutionize turbine propulsioD. and that a speed hitherto unknown will Ik? |k>ssible. although only two blades are used as against the many thousands in each of the new C'unarders. Another engineer, living in Liverpool has also invented an engine which he claims is better than the

turbine. The cost would be less, he says, the speed and power greater, while there is no part of the engine that could not be made in a small en-gine-shop. It needs the smallest amount of packing and oil. and,- astounding as it may socm. in its internal construction it has neither nut nor lolt.—"Tit-Bits/'