Hydrant Tests at Elkhart
Tests of water pressure at hydrants and nozzles through different lengths of hose, made by Chief Dotson at Elkhart, Ind., last week, were witnessed by the mayor and other officials, and four representatives of the Indiana Underwriters Bureau, and demonstrated the loss of pressure by friction in long lines of hose. The tests showed the average loss of pressure between hydrant and nozzle as approximately seven pounds for every 100 feet. 100 feet of hose attached to a hydrant with seventy pounds pressure would show sixty-three pounds at the nozzle. Through 500 feet of hose the pressure at the nozzle would be but 35 pounds. The first test was through six lines of hose. Four were 550 feet each and two were 500 feet each. The test did not result in what the chief considers good fire fighting pressure. The second test was made to duplicate the conditions that existed at the time of the tablet company fire. Two 550 foot lines were laid from the hydrant west of the building, one of 300 feet from the hydrant in front, one of 100 feet from the hydrant east, and two of 50 feet each from the sixinch pravatc main of the Elkhart Paper Mill. The tests showed that on the 300-foot line with a hydrant pressure of forty-seven pounds, thirty-five pounds was given at the nozzle, or a reduction of four pounds to the 100 feet. This, however, was when one line of hose was used. For the 550-foot lines the reduction was from sixty pounds at the hydrant to thirty at the nozzle. For the 700-foot line the nozzle pressure was but thirteen pounds. There was no gauge on the hydrant. The 100-foot line showed thirty pounds at the nozzle and the fifty-foot line showed fifty pounds. There were no gauges on the hydrants. When six streams were taken from hydrants on the same main at the same time, the hydrant pressure was seventy pounds; five streams, seventyfive pounds; four streams, same; three streams, seventy-nine pounds; two streams, eighty-four pounds; one stream, eighty-five pounds. The seven pounds per foot reduction for each 100 feet of hose as showing the difference between hydrant and nozzle pressure proved nearly accurate in all these tests. The hydraulic engineers present were E. R. Townsend of Chicago, W. I. Stone and E. M. Sellers of Indianapolis and F. C. Powell of South Bend.