An analysis of the hydraulic transients in pipelines caused by failure of power to pumps is undertaken in this paper, using dimensionless-homologous pump data and the method of characteristics equations for a waterhammer. The equations are solved by means of a high-speed digital computer. To illustrate the analysis, a pumping station is located in a pipeline between two reservoirs. In the station are a number of identical, parallel pumps. Any number of the pumps may suddenly lose their power. A valve may be located at each pump discharge and may be closed in an arbitrary manner (or as a check valve) when triggered by the loss of power. The effects of large friction heads as compared with large gravity heads are examined, together with the effects of diameter change and valve closure timing.