WATER SUPPLY OF CAMBRIDGE, MASS.
PAYSON Park new high service reservoir at Cambridge was begun in 1894. Its capacity is 43,100,000 gallons; located above city base 178.50; distance from Stony brook basin, 6 5 miles; length of forty-inch steel pipe, 23,450; area of reservoir site, 11.75 acres; area of water surface, 7.38 acres; distance from pumping station, 8,586 feet; distance from Hobbs brook basin, 6.2 miles. The work was completed this year, under the supervision of Chief Engineer Lewis M. Hastings, Consulting Engineers Marshal M. Tidd, 1894 95, and Messrs. Rice and Evans, 1896; assis’ant engi neer, George Davis; engineer in charge, J. Wilder Howe. It is connected with Fresh pond pumping station by two fortyinch main pipes. All the water that comes into the reservoir is pumped from that pond, and the stored supply is sufficient for si* days on the present basis of consumption, while the pressure is now such that water can be thrown from the hydrants over the highest buildings without having recourse to steam engines.
The new high duty, vertical, triple exjransion 20,000/00gailon Groshon Dump is built on the most up-to date principles It stands between (he two old pumps in the Fresh pond pun ping station; is fifty-four feet high from base, weighs 500 tons; is of 700 horse power; and has five boilers of 1,000 horse power each. In the condenser, a vacuum of twenty seven inches of mercury (thirteen and one half pounds) pressure is constantly maintained. In the high pressure cylinder the steam has a pressure of 800 pounds per square inch, with a temperature of 382 degrees Fahr. This pressure falls to six and two third pounds, and the temperature to 170 degrees, by which a maximum economy of heat and coal is utilized. The piston rods of the steam cylinders a e connected directly to the main crossheads and also connected to a beam or rocker, which is also connected with the main crank on the flywheel shaft,whereby the work in the pumps is made uniform throughout the stroke, 1’he engine can raise nearly five times the available storage capacity of the Hobbs brook basin from Fresh pond into the Payson park reservoir in one year, an ‘ will raise t.000,000 gallons of water into the Payson park reservoir from that pond— a distance of 9,000 feet and 180 feet above the pond—with t.ooo pounds of coal, with coal costing $t.8o per thousand pounds, or 1,000,000 gallons one foot high for one cent. The two new boilers at the Cambridge pumping station are of the Belpaire firebox type, each of one thousand maximum horse power and weighing forty-five tons.
The leading dimensions of the pumping engine are as follows: Diameter of high pressure cylinder, 18 1-2 inches; diameter of intermediate cylinder, 33 inches; diameter of low pressure, 52 3-4 inches; diameter of differential pump plungers, two upper. 19 3-8 inches; diameter two lower, 27 3-8 inches; stroke of pistons and pump plungers. 90 inches; resolutions per minute, 32 inches.
The work of building the addition to the water system was begun during the mayoralty of William A. Bancroft, with J. M. W. Hail as president of the water board, Walter H. Harrington, clerk and registrar, John L. Harrington, superintendent, Edwin D. Brooks , acting superintendent, and C. Brunei Parkes, assistant superintendent. Mr. Erasmus P. Leavett,likewise, was of infinite service as consulting engineer.
The illustrations accompanying this notice are as follows: Payson park high service reservoir and gate house; Winter street gate house—lower end of Hobbs brook basin; middle section of lower Hobbs brook basin; and Hobbs brook basin — lower section, near the Winter street gatehouse.