Coney Island High Pressure System.
A most important question which must be considered by the small town, the coast communities and the large or isolated manufacturing plant has reference to fire protection. The matter of expense enters in pretty much every such case. In addition, there is the problem of an adequate water supply under sufficiently high pressure. It is possible, as has been proven in many instances, to solve the whole problem by means of a powerful pumping plant operated only when necessity arises. A case of this kind is that at Coney Island, the New York pleasure resort. The buildings at this place have been and are very inflammable. In consequence of the conditions, fire policies were limited to 10 per cent, of the value, and a 5 per cent, rate charged. The location is distant from the general fire system of the borough of Brooklyn. To maintain an adequate number of fire steamers to cope with the possibilities, would have entailed a very heavy expense. An abundance of water was, however, available, hirst, there was the city supply, and second, the salt water of the immediate vicinity, if such water could he used. The question of power was, of course, important. What was needed was a solution of the power question which would enable a large total of power to become available quickly, and would entail little or no expense in the intervals when not required. This problem was successfully solved by using gas engines and supplying them with the ordinary illuminating gas. A large gas holder was situated near by, to which suitable connections were made. Three Nash gas engines of the vertical, three-cylinder, four-cycle type were installed. The cylinders are 13¾ inches in diameter, and stroke 16 inches. When these engines are run at 200 revolutions per minute, a horsepower of 175 is developed by each. This is accomplished with gas of but 590 B. T. U. per cubic foot, by using only 17.4 cubic feet per brake horsepower per hour. The valves of one cylinder in each engine are arranged to permit the use of compressed air to start it off. There are two separate air compressors. One of these has its own small gas engine. The other compressor is driven by one of the main engines. There is in addition, a series of storage tanks for compressed air, with capacity equal to starting all engines twice. It will be seen from the foregoing that very adequate provision has been made for starting up. In fact, the men ip charge do not have lo exert themselves at all. The compressed air starts the engine forward, operating through one of the three cylinders. The other two cylinders quickly develop power from the gas, in one or two revolutions. The engine is put into full operation by gas in 20 seconds. All three engines and the whole plant can he put into full operation in about 2½ minutes. It will thus he seen that a source of driving power becomes available in a very short space of time. This power equipment drives a very efficient pumping plant. This consists of three triplex double-acting piston pumps, built by the Goulds Manufacturing Company, of Seneca Falls, N. Y. Each of these pumps is directly connected to one of the gas engines, and forms with it a water handling equipment independent of the other pumps. The pistons have a diameter of 12 inches and a stroke of 11 inches. There is a capacity of 40.3 gallons at each revolution of the three-arm crank-shaft. As the ordinary angular speed of the crank-shaft is 38.5 revolutions per minute, it gives a pumping capacity of 1,651 gallons per minute per pump. Each pump is driven by a pair of pinions which engage with spur gears arranged on the ends of the crank-shaft. The gear ratio is 1.5. The suction piping has a diameter of 12 inches; the discharge piping, 10 inches. Each of the pumps has a by-pass permitting the discharge to pass into the overflow pipe. While the engine is getting under way, the by-pass valve is open,-but when the full speed is attained, it iis gradually closed by an electric motor. The valve is opened or closed in 20 seconds; the electric motor automatically stops when its work of opening or closing the valve is completed. The total capacity of the three pumps is 4,650 gallons per minute. The pressure is 150 pounds per square inch at the pumps. For a hydrant seven-eighths mile away, the pressure falls only to 140 pounds, when the full capacity of the plant is employed. The area protected totals about 65 acres. There are numerous hydrants so distributed that the whole energy of the pumping plant can be concentrated upon any one block of buildings. These hydrants have 2 1/2 hose connections, and are joined to the service mains by 8-inch piping. The full capacity of 4,650 gallons per minute can be developed with 15 to 20 streams. City water is brought into the plant. In addition, there is suction connection with an adjacent body of water known as Coney Island creek. This water is salt, and the supply is inexhaustible. In case the city water should fail, the salt water supply could be utilized.
This pumping plant seems to have been admirably conceived. It is economical, as it is operated only when needed. The attendance expense is low. It can be started up with great rapidity and with great certainty. The whole plant need not be put into operation if the situation does not require it.
The high pressure pumping plant had a real tryout in 1907, during a serious conflagration. The total capacity of the plant is, as has already been stated, 4,650 gallons per minute, with a pressure of 150 pounds per square inch at the pumps.
A few weeks ago a great conflagration broke out. The plant has never been increased in capacity by additional units, although the size of the place has grown and the total length of mains has been much extended, ft is said that as many as 30 connections were made during this blaze. There could be but one result, a great loss of pressure. Some people have taken the view that the plant could be expected to furnish any quantity of water at high pressure that an emergency might happen to require. A gas driven pumping plant cannot be expected to do more in such a situation thah an electrically driven one. Deputy Commissioner J. W. E. Bennett states that the pumps worked satisfactorily during the recent fire, but that the overdraft “necessarily resulted in the reduction in pressure shown on the charts.” The capacity is such as to supply 15 or 18 lines of hose with high pressure streams. To get 30 or 36 such streams is not difficult; it is only necessary to duplicate the plant.