A friend and I were having a conversation the other night about broken knuckles - we wondered why there hasn't been a modification to couplers that would result in an automatic separation in the event of extreme draft forces instead of a knuckle breaking. This way, knuckles wouldn't have to be replaced, although a crewman would still have to walk back to make the joint and lace up the air hoses again.

Aside from massive costs to retrofit old cars with this hypothetical invention, and not much of a ROI (aside from railroaders saving their backs, which management probably won't care about too much) we agreed that something like that wouldn't really be needed. Thoughts?