A New Train Performance Calculator

This paper describes a new train performance calculator recently placed in service by the Pennsylvania Railroad in Philadelphia. This calculator was developed to compute and record mechanically and quickly information required by a railroad to determine the economics, application, proper size, and tonnage ratings for new types of motive power, which information previously was assembled from a large number of tedious step-by-step mathematical calculations. The machine consists of three self-balancing, potentiometer-type, curve-drawing instruments, electrically interconnected, and a low-energy auxiliary circuit. The latter contains apparatus necessary to represent effective forces which influence the movement of a train and to represent certain types of motion which must be calculated to determine the performance of a theoretical train. The simplicity of its control and operation makes it suitable for continuous use in a quiet engineering office.