Disclaimer: I’m not a mechanical or design engineer. I don’t have experience building railcars or investigating derailments. This is my opinion/speculation.
So if I’m reading things right, the bolts that hold the draft gear and couplers in place are designed to shear off? Who thought this was a good design? That completely defeats the purpose of the tight lock couplers that are required on passenger cars. My understanding is that the Type H couplers were to prevent cars from coming uncoupled and turning sideways (the accordion effect) by keeping cars coupled and in line during a derailment. As others have stated, dropping a big heavy drawbar or coupler under a moving train poses other issues as well. So who thought this was a good idea and what is their justification for it?