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Date 2. Ss wi wi sas ea ee Oct. 230; 1908: Distance os cs hes oss ie eet ee 5% miles Time mean of two hours.we<.0 2.) 28.25 min Speed (statute.-miles per 'hour)<i3... 4. Paley R. P. M.; starboard motor. ica23e5.. 179 R. Ps M., port motor... wwe 178 Developed horsepower :-- Motors, starboard: ..0.. s:2:440 3 203 Motors, port 000.0. oes ee ee 166 Output of «generators, starboard. +s... 20, 223 Output of generators,, port. .s.. 5205. ee 181 Motor efficiency, starboard, per cent...... 9130 Motor efficiency, port,..per 'cent... 44... 91.8 The data obtained from the fore- going test shows not only that the centrifugal pump is a more powerful and reliable machine than the old type, but also that the greater econ- omy of the turbine outfit makes it possible to do more work with about half the boiler capacity. Comparing the water rate of these turbines with that of a high-pressure pump taking steam for almost full strokes demon- strates the fact that there is prob- ably no boat afloat of the same size that has the pumping capacity of the Joseph Medill. While the guaranteed capacity of the boat was 9,000 gallons per min- ute, the eight-hour endurance _ test showed an average delivery of 9,600 gallons. As may be surmised, the build- ers ran the test with the idea of ful- filling their contract and not to make a record." Jt 18> Sate to Say that dius boat, if crowded, will deliver between 10,000 and 11,000 gallons of water per minute at 150 pounds pressure. Discussion, Mr... J. G Winship: In. 'this .paper by Mr. West describing the Chicago fire-boats, designed by Mr. W. I. Bab- -more than the pumps specified. TAE Marine Review cock, I wish to compliment Mr, Bab- cock on his original method of com- bining a centrifugal pump and elec- tric generator to a steam turbine and driving the boat with motors, But to New York belongs the credit of being the first to use the centri- fugal pump on fire-boats and to Fire Commissioner Hays, is due the credit of having the courage of breaking up the habit of the New York Fire De- partment in waiting until the improve- ment has been tried in the West be- fore taking it up here. Upon the earnest solicitation' and guarantee of the Henry R. Worthing- ton Co., it was agreed to try the cen- trifugal pumps on the two projected fire-boats with the rigid specification that in case the pump failed to per- form the work guaranteed on the first or second trial, the contractor was to remove them and _ should install in their place, reciprocating pumps sim- ilar in design to those on the "Abram S. Hewitt,.:and to be. of the same number and_ size, which would cost The engines, pumps and boilers were laid down and then the boat was laid out around the machinery. The designers, Messrs. Millard & Maclane, did their work nobly, producing a boat _ that went away ahead of the specifications. The boats are 123 ft.. long, 27 ft. wide and 14 ft. 9 in. deep.. On. trial the boats made a speed over the measured mile at Riverdale of four (4) minutes 2a. and twelve (12) seconds, going up against the tide, and three (3) min- utes and thirty-five (35) seconds go- ing down, equal to 15.38 miles per hour. The main engine is a fore and aft compound with cylinder, 18 x 38 x 26 inches. Steam supplied by two Bab- cock & Wilcox boilers each having 2,250 sq. ft, heating surface with 63 ft. grate surface... Air tight fire room with a blower discharging 20,000 cu. ft. per minute, steam pressure 200 Ibs. One surface condenser having 2,700 ft. of surface in which the main engine, turbine engines and electric light engines exhaust. The air pump is a Blake vertical twin beam with cylinders. 9. s:18 x 12. inches, Cae feed water heater has 180 ft. The fire pumps are arranged in two units in each boat, each unit to deliver 5,500 | G. P, .M.. against 125 Ibs, "pressure, or 4,500 G.. P. M. against 150 Tae. pressure, when operating at 1,800 revolutions per minute, when the tur- bines are supplied with 10,000 Ibs. of dry steam per hour, and 26-inch vacuum. The fire pumps are driven by General Electric turbines of 600 horsepower each. To show how lib- erally the boats were furnished with power, one of the boats on trial ran from West Twenty-third street to the Battery, with the engine making 160 revolutions per minute, both pumps running carrying 150 lbs. pres- sure, the boilers maintaining 200 Ibs. PLATE 4.--PLAN VIEWS OF THE ELECTRICALLY PROPELLED CENTRIFUGAL PUMP BOATS REFERRED TO IN THIS PAPER.