VII. THE “TURBINIA.”
In June, 1897, there appeared on the Solent, at the time of the great Jubilee Naval Review, a steam vessel furnished with a novel method of propulsion, by which a speed far in excess of any previous record was attained. In the opinion of competent experts this new application of steam-power is likely to bring about in the near future a revolution in steam navigation. The following account of this phenomenal craft appeared in the Montreal Star:
“London, July 5th, 1897.
“The record-breaking 100-foot torpedo boat Turbinia has intensely interested the public here generally, and experts in marine engineering in particular. It is admitted that if the principle of the steam turbine invented by Charles Parsons and fitted in the Turbinia can be extended to large ships, it will mark the greatest revolution in mechanics since the invention of the steam-engine itself.
“Mr. Wolff, M. P. for Belfast, head of the famous firm of Harland & Wolff, of Belfast, and himself the designer of the White Star Liners, says:
“‘I saw the Turbinia at Spithead going nearly eight miles an hour faster than any vessel had ever gone before, and even then she was not being pushed to her full speed. She passed quite close to the Teutonic, on which I was. She dashed along with marvellous speed and smoothness.
“‘I must say, however, that I felt more secure on the Teutonic than I should have felt on the Turbinia, for you know they have not yet surmounted the difficulty of reversing the engine. She can go ahead forty miles an hour but can only reverse at less than four.
“‘If Parsons can make a similar turbine engine practicable for big craft with proper reversing power, he will open a new era in the history of steam motors. But, although he has carried the economizing of steam to a great pitch for a turbine engine, still from my observation the waste of both steam and fuel under his system, if applied on a large scale, would be almost fatal. That there is a big future before his turbine engine for launches and other small craft I do not doubt, provided that he can get over the reversing difficulty.’”
The Scientific American, in its issue of June 26th, 1897, says: “Nothing more startling has ever occurred than the wonderful runs which have recently been made by a little craft called the Turbinia, in which the motive power is supplied by a steam turbine of the Parsons type.”
Quoting from a paper read at a meeting of the Institution of Civil Engineers in London, by the Hon. Charles A. Parsons, the inventor of this new system, the advantages of the turbine system are thus summarized:
“(1) Greatly increased speed, owing to diminution of weight and smaller steam consumption; (2) increased carrying power of vessel; (3) increased economy in coal consumption; (4) increased facilities for navigating shallow waters; (5) increased stability of vessel; (6) reduced weight of machinery; (7) reduced cost of attendance on machinery; (8) reduced size and weight of screw propellers and shafting; (9) absence of vibration; (10) lowered centre of gravity of machinery, and reduced risk in time of war.
“The Turbinia is 100 ft. in length, 9 ft. beam, 3 ft. draught amidships, and 44½ tons displacement. She has three screw shafts, each directly driven by a compound steam turbine of the parallel flow type. The three turbines are in series, and the steam is expanded—at full power—from a pressure of 170 pound absolute, at which it reaches the motor, to a pressure of one pound absolute, at which it is condensed. The shafts are slightly inclined, and each carries three crews, making nine in all. The screws have a diameter of 18 in., and when running at full speed they make 2,200 revolutions per minute. Steam is supplied from a water tube boiler, and the draught is forced by a fan, mounted on the prolongation of the low pressure motor shaft, the advantage of this arrangement being that the draught is increased as the demand for steam increases, and also that the power to drive the fan is obtained directly from the main engines.
“Up to the present the maximum mean speed attained has been 32¾ knots, as the mean of two consecutive runs on the measured mile. These runs were made after about four hours’ steaming at other speeds, and the boat on the day of the trials had been fifteen days in the water. It is anticipated that on subsequent trials, after some alterations to the steam pipe, still higher mean speeds will be obtained.
“It is believed that when boats of 200 feet in length and upward are fitted with compound turbine motors, speeds of 35 to 40 knots may be easily obtained in vessels of the destroyer class, and it is also believed that the turbine will—in a lesser degree—enable higher speeds to be realized in all classes of passenger vessels.”
Referring to the difficulty of reversing the engines of the Turbinia, the Scientific American adds, that “by using a system of ‘butterfly’ reversing steam valves, a motor has been constructed in which the steam may be made to flow through the blades of the turbine in either direction, the whole horse-power of the engines being thus available for going astern.” Detailed drawings and descriptions of the Turbinia and the new motor may be found in the supplements of the Scientific American (New York) for June 26th, 1897, and March 12th, 1898.