THE WATERWORKS SYSTEM OF DULUTH

THE WATERWORKS SYSTEM OF DULUTH

Specially written for FIRE AND WATER ENGINEERING.

明尼苏达州德卢斯。,坐落在一座小山。我ts principal streets are laid out one above the other and run the whole length of the city in terrace form, terminating on the highest level in a handsome public park from which a fine view of the great grain elevators, s.oragehouses, wharfs and lake Superior may be obtained. It is a very prosperous, hustling city and an important point for the shipment of grain, ores and general merchandise to all parts of the world. It was incorporated in i88, and the waterworks system wa cot. structed in 1893 by the Duluth Gas and Water company under a franchise for thirty vears. The system is pumping to reservoir from lake Superior. The intake-pipe is laid 9 miles down the lake from the centre of the city leading from a crib 1.500 ft. from the shore'and laid a’ a depth of 65 ft There are two pumping stations, one at Lakewood, which is e«|uiped with two 6,000,000-gal. pumping engines and a 12,000,000-gal. engine driven by electricity. At one if the two reservoirs i a pumoing plant equiped with two 6o-ll.1V. gas engines, shown in the illustration, which supply what is called the middle system. At the tanks connected with this system, which are located at an elevation of 213 ft. above the initnnhonso, is another pumping plant equiped with one 20 11.1, gas engine and one 6o-ll.l., ga engine, which supply the upper system at a further elevation of 175 ft., or a total height above the lake of (65 ft There are three reservoirs, one 13,500,000-gal. capacity, another of 5.000,000-gal. and a third of 10,000.000-gal. capacity. Water is pumped to these 295 ft. above the lake, the greater portion of the city being established on the hilt-side with n the hydraulic level of the lower system The contract for the 12.000,000-gal. centrifugal electric pump was awarded to the General Electric company at a cost of $25,000. and it has been in operation at Lakewood station since June. 1907. This pump gives a double pumping capacity available in all cases where it may bo necessary to increase the supply or repair the other engines. The reservoir at West Duluth was constructed in 1906. Its capacity is 10,000,000 gal. making the reservoir supply of water stored in the thre reservoirs, 28,000,000 gal. A double line of pipe was laid to this reservoir, so that on eline could be used as a supply-pipe, and the other as a return-flow to the West Duluth territory, in order that a constant circulation might be kept up ami the purity of the water preserved. An auxiliary system has also been completed at Duluth Heights at a cost of over $19,000. This system, which was built and successfully completed in IQ05, is an independent works, the water being obtained from wells. It consists of four 6-in. drive wells, discharging ipt a io-in. overhead main. 1eadin to a receiving basin, into which the water flows, and from which it is pumped. By this means any suction from the well is prevented. By ⅜ test made upon the completion of the system the flow from the wells showed a flow of 82,000 gal. in twenty-four hours, which is three or four times the present consumption. The work on the middle system, as given by L. N. Case, manager of the works, consisted in the laying of 43,562 ft. of water and gas mains, leaving 8.700 ft. to be laid this year. The pipes of this system were extended no farther north than Ninth street, and water and gas were turned nto them on December 21 from the Normal system, and to the extent of the elevation of the tanks of the system, which is 489 ft. above the lake, the water is being su udied to-day. The works this season will be the extension of the 12-in. reservoir-oipe to Thirteenth street, where three tanks, with a combined capacity of 560,000 gal. will be erected, bav ng an elevation of “-o ft. above the lake, upon the completion of which the Normal tanks on Woodland avenue will be abandoned, and the system hitherto known as the Normal system and the Hillside system will be henceforth known as the Middle system. According to the figures of the manager of the water and light departments of the city, the distribution has been greatly extended to meet the demands caused by the improvements to the plant during the past year. The total mileage of pipe now is 94 miles, varying from 3-in. to 42-in. in diameter. There are 669 hydrants and 2,338 meters set, and the service-connections number 6,286. Under good management and a liberal outlay for the extension of the works, a considerable surplus derived from water receipts remained to the credit of the water department in 1907.