Trailer Loader

Innumerable searches later (very hard to find out about something if you don't know what it's called; "guillotine" didn't work at all as a search term), it appears that all those trailer hoist thingies are the same brand, they are MAR Hook Trailer Loaders; and they work the way I was beginning to imagine they must: "The patented reach guide yoke stops the trailer from turning while it is suspended."

These critters are everywhere around the North Peninsula.