都市水道配水管網の消火用放水能力實験について

抄録

In order to ascertain discharging capacities for fire extinguishing purpose of the municipal water supplying nets, the Fire and Marine Insurance Racing Association of Japan with assistance and co-operation of the Waterworks Department of Tokyo Municipality and Tokyo Fire Defence Board, experiments took place on 24th October, 1950 at one section of Koumecho Sumida-Ku, Tokyo, the result which is as follows :
Experiments were made to ascertain natural hose discharging and pump discharging capacities and pressure at hydrants
(1) a single pipe line (2) net lines.
We have computed the distribution of flow and friction loss for each pipe line in accordance with Hardy-Cross method by using Williams-Hazen formula, and compared the values obtained with the results of the experiments.
We have found that in the case of the pipe net, the mean value of velocity coefficient C in Williams-Hazen formula is 44, that is, the discharging capacity is 44 percent of that for the case when C is assumed 100 as for ordinary cast iron pipe line.