Locomotive Air Brake Modification
The foundation brake rigging of GE class C30-7 locomotive underframe was re-designed and converted to operate as a freight car, complete with Group M handbrake. This project utilized the underframe and trucks of the locomotive hulk, and was refitted with freight car control valves and appliances as necessary to enable the truck-mounted cylinders of the locomotive trucks to provide freight car braking performance, as the unit is hauled as a freight car while in train service. The size and performance characteristics of the locomotive brake cylinders were determined and compared with those of the typical freight car cylinder, and the necessary relay valve and reservoir sizing designs were developed to enable proper operation. The layout of the components was determined for proper placement. The original locomotive handbrake was determined to be of insufficient capacity to meet current AAR handbrake performance requirements, thus a high-capacity lever type freight handbrake was mounted to the unit, and attached to the existing locomotive handbrake linkage with new chain routing, providing proper operation. Subsequent dynamometer brake shoe testing of the braking system confirmed predicted performance.