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MARINE, REVIEW. -- 13 Turbine Engines in a Torpedo Boat. English trade journals contain extended accounts of the perform- ance of the Turbinia, a British torpedo boat which recently attained a speed of 29.6 knots over the measured mile and which is driven by a turbine. In dimensions and appearance the vessel is similar to other first-class torpedo boats of the British service. She is 100 feet over alland 9 feet beam, and has a displacement of forty-two tons. The Newcastle Chronicle says of the craft: 'One is struck at first glance by the compactness of all her fittings. In a torpedo boat of the ordinary type everything is sacri- ficed to engine space, and the machinery contributes most largely to the weight, but the engines of the Turbinia weigh only four and a half tons. They are right at the bottom of the vessel, against the skin. The advantages of this are obvious, especially in a war boat. It gives greater steadiness and obviates qesiraciion of the machinery by an un- welcome shot. The total weight of the machinery including the boiler and condensers, is believed to be not more than two-thirds of that of machinery of equal power of the ordinary kind and of the lightest manufacture. There is only: one water tube boiler, which has 1,100 square feet of heating surface and 42 square feet of grate surface, with the furnaces fired fore and aft from two closed stoke- holds. Forced draft is obtained from a fan driven off the main en- gine. Itis claimed that the turbine engines allow for a total expan- sion of the steam of 100 fold, instead of sixteen fold, as is usual in triple expansion engines of the ordinary kind, and that in the case of some recent tests of condensing turbine engines of 200 horse power, applied to driving dynamos, a steam consumption of less than 14 pounds per indicated horse power had been recorded, with a boilec pressure of 80 pounds per square inch, and that it was believed in the engines of the Turbinia, developing many times this power, a greater rate of economy than this figure was realized. The boiler pressure in the case of the Turbinia is 225 pounds per square inch, and the pres- sure at the turbines is 150 pounds. Lightness of machinery will permit of parts being carried in duplicate, which is ,of course, a great _ advantage. '""Among advantages claimed for this system. of piapuldion are increased speed, increased carrying power of the vessel, increased economy in steam consumption, increased facilities for navigating shallow waters, reduced initial cost, reduced weight of machinery, reduced cost of attendance on machinery, diminished cost of up-keep of machinery, largely reduced vibration, and reduced size and weight of screw propeller and shafting. The motor is the invention of-Mr. Charles A. Parsons, whose compound steam turbine is well known. Its novelty now is in its application to the propulsion of-a vessel, The turbine, in its elementary form, is exceedingly simple, but the engine designed by Mr. Parsons is a complicated and beautiful piece of mechanism. It is, in effect, a series of wheels, fixed and parallel, multiplying thousands of times the driving power of a single wheel. It consists essentially of two parts--first, an outer cylindrical casing, which is fixed, and an inner barrel, which is in effect a broad wheel, in motion, and has the propeller shaft running through it longitudinally. Projecting from the inner surface of the outer casing are parallel sets of fixed vanes, called guiding blades, and from the circumference of the barrel or wheel are sets of blades, the former directing the motion of the steam toward the latter. In order to avoid shock in the diver- . sion of the energy from the guiding blades to the moving blades, and -- to reduce the residual velocity of the power leaving the wheel, the parallel flow was adopted in the compound steam turbine, in preference to what is known as the outward and inward flow. The guide blades are cut on the internal periphery of brass rings, which are afterwards cut in halves and held in the cylinder by feathers. The moving blades are cut in the periphery.of brass rings, which are afterward threaded and feathered onto the steel shaft and retained there by the end rings, which form nuts screwed onto the spindle. The spindle and its rings rotate together in bearings. Steam is admitted at the inlet, flows to the right of the spindle and, passes along to the left, first through the guiding blades, by which it is thrown upon the moving blades. Then it goes on to the next guiding blades, and is by them projected against the corresponding moving blades and so on through the whole series, escaping at the end of the cylinder by an exhaust pipe. Inthecompound turbine the velocity of the blades is sufficient to secure a very high return of useful effect. Each turbine gives an efficiency of at least 80 per cent. As each turbine discharges without check into the next, the residual energy, after leaving the moving blades, is not lost, as in the case of the water turbine, but continues to the next guiding blades, and is wholly utilized in assisting the flow. A new factor in marine propulsion is introduced by the propeller being driven at the enormous rate of 2,400 revolutions per minute, the highest rate up to the present being about 700 revolutions per minute, thus enabling both the shafting and propeller to be reduced accord- ingly." A Ton of Cargo 30 miles on One Pound of Coal, In view of the attention that has been given of late to the ques- tion of adopting artificial systems of draft for lake frieght steamers, it may be interesting to note that some of the best ship building con- cerns of England, among them Sir Wm. Gray & Co. of West Hartle- pool, make reports in English trade journals showing that in several vessels which they have built, the Howden hot draft gives 13 to 14 per cent. more steam per pound of fuel than they were able to secure with natural draft. The Afghanistan, a vessel recently built by this firm and engined at their Central Marine Engine Works, carries 5,700 tons merchant's measurement, or about 4,000 tons dead Ween at 94 knots on 14 tons of coal per day. If the dpeed is made 10 knots, a standard for comparison, the result is one pound of coal moving a ton of cargo thirty miles. Dimensions of the vessel are 306 by 43 by 21 feet, and the engines are triple expansion with cylinders 23, 364 and 62 inches diameter by 39 inches stroke, the working boiler pres- sure being 160 pounds. The builders, who have constructed a large number of vessels of this kind with nade without artificial draft appli- ances, and who have had a great deal of experience with the Howden draft, claim that there is a gain of boiler weight in this vessel of fifty tons, as only one boiler, 15 feet 6 inches diameter by 11 feet 6 inches length is required, as against two that would be required without the draft.. They claim also that while reducing the weight there is no curtailment of the efficiency-making proportions of the one boiler, for it gives as much heating surface per foot of fire-grate as it was formerly customary to give to twice that area of grate. There is 2,920 feet of heating surface for 62 square feet of grate. This is in the boiler proper, in addition to the Howden heating surface, which pick up the truant heat of the smoke, 47 square feet of heating surface per foot of grate, or 2 square feet per pound of fuel per hour. Success attained by this firm of builders in the use of the Howden system is made up largely, it is claimed, by careful attention to the most minute details and by perfect workmanship. All tbe smoke- box doors and the furnace doors are hermetically jointed with asbestos tape. There are valves on the furnace doors for regulating the ad- mission of air above or below the bars in such proportions as to pro- duce the most perfect combustion, as seen by looking through a small pane of mica which is fitted in the door. The side fire-bars are jointed close to the sides of the furnaces to prevent active combustion in contact with the plate which is so productive of pitting. Beneath the boiler there is no water ballast tank in the vessel, because the tops of tanks under boilers deteriorate very rapidly, owing to the heat from the boiler. There are the ordinary floors and strong stringer plates instead. ' Edwin H. Whitney, member of the Ainerican Society of Mechan- ical Engineers and the Society of Naval Architects and Marine En- gineers, is now the chief engineer of the Marine Machine & Conveyor ~ Co., 111 Broadway, New York. This concern owns patents and is engaged in the manufacture of coal handling machinery, steam stear- ing gear, capstans, gypseys, steam shovels and other marine machinery. The officers are George F. Mellen, president; Thomas 8. Mathewson, vice-president and manager; G. A. Gates, treasurer ; J a G: Faist, secretary.