Most of us probably have seen several industry-produced films about the importance of low speed coupling. Several films I've seen focused on unfortunate families that received furniture or appliances damaged by poor railroad freight handling practices.
But what about the boxcar?
The eighteen minute movie, "The Freight Goes Through!", was produced by the Association of American Railroads in 1952. It's another one of those films about the importance of low speed coupling. And nine minutes into the film, using a cut-away boxcar, it shows in slow motion what happens to a load when coupling occurs above a recommended speed.
Ten minutes into the film it shows, again in slow motion, what happens to the boxcar as a result of coupling at higher speeds. Wow. Now I know why roofs had to be flexible. The car sides take a beating as well.
Have a look: