A method of determining resultant input from individual duty cycles and of determining temperature rating

V. Karapetoff: Let us take a machine shop, say with thirty identical machines, where thirty operators perform the same operation, for instance, turning a rod to a smaller diameter. Before each machine-tool raw parts are piled up, and when the whistle blows in the morning these men begin operations. Each one takes a piece, fastens it in the lathe, runs the cut, unfastens the piece and puts it back on another tray. Then he takes again another piece and performs the same operation. But all operators do not start at the same instant. Mr. Jones assumes that each machine is driven by an individual motor and as soon as the operation is completed the motor is stopped. Because the men do not start at the same instant, there is some phase displacement in the cycles, and Mr. Jones´ problem is to evaluate, by the theory of probabilities, the demand on the power plant under those conditions.