For years, railroading's gondola cars (on the railroad, pronounced gun-DOH-luh, GON-doh-la is a boat in Venice) came in forty foot varieties with or without drop bottoms, for stones or ores or coal, and a century ago the way for a consignee to empty one when dropping the bottom wasn't an issue was to hire a high school kid to shovel it out (!) and in longer varieties called "mill gondolas," which might or might not have had drop ends and sometimes hardware for handling long steel products. Sometimes older gondolas would be relegated to hide service. You wouldn't want to marshal them close to the caboose on a train, and pity the hobo who didn't see a pile of something geologic and thought that would be a convenient car to stow away in.
Of late, though, the gondolas sometimes look like this one, on the old Milwaukee Road at Sturtevant. They're operated by
Secure, a Canadian company, and, yes, they function as giant rolling dumpsters.
And yes, this mutation of gondolas has been under way for some time. As power companies closed their coal-fired generating stations, a sizable fleet of bathtub gondolas, equipped with solid bottoms and rotary couplers in order to unload a train much faster than an army of high schoolers with shovels could do it, cascaded into railroad maintenance service as well as rolling bins that could carry more scrap bundles than your basic forty foot gon of days gone by.