I was asked a while back about making an extended shank version of my couplers for the AML 50’ Hi-cubes. The more I looked at prototype photos, the more I began to think I could do better than just stretching the shank. The prototype uses a Keystone End-of-Car Cushion Unit. Having already done a large chunk of the design work on previous projects, I have decided to try to adapt those to the AML car.
I had a run of draft sills done in .030” photo-etched brass. They are longer than this car needs, but easily trimmed down:
I was hoping I would be able to use the AML underframe, as is. However, when I got my hands on one, I found that they lowered the floor for the coupler mounting pad:
This will make my draft sill ride lower. I haven’t made my mind up if I’ll cut the mounting pad off, or raise the coupler head in my drawings. There is no interference with the trucks either way. I will have to cut out part of the molded-on draft sill though:
Exploded view:
The prototype EOC allows for 15” of travel in the buff position (compressed). After studying the CYC drawings, I have realized they appear to only allow minimum travel in the draft position (tension). The prototype uses a hydraulic piston. I think I can model this with a spring.
