Modify Heavyweight Passenger Car to Accept New Larger Trucks & Adapt Brake System

A heavyweight passenger car, built by the Canadian National Railroad in the late 1920s, was modified to operate with a larger set of trucks than originally designed. Additionally, the car's braking system was modified. This re-design incorporated changes to the cylinders, slack adjusters, and all connecting linkages, to the control system on the car, which was converted from U12C control valves to 26C control valves. The underframe was modified to accept the larger trucks, which involved designing and cutting reliefs in the lower center sill flanges to accommodate curving, and relieving the contour of the vestibule steps to clear the truck frame on curves. Additionally, the end electrical junction box arrangements were modified to provide truck clearance on curves.