Awhile back I was hired to work in Savannah on the Amazon series Underground Railroad. Specifically I was a Special Effects Welder and Technician. It was supposed to be a six week project, but turned into five months- and it was loads of fun. The coordinator was Bruno VanZeeBroeck, who has a very impressive resume… one of his early credits was for Return of the Jedi. I wasn’t allowed to post anything about it at the time, which is standard procedure these days, but this show has long since aired.
Our main project was to replicate a steam train by building a steel and wood “jacket” that fit over a small diesel switcher at the Savannah RR Museum. It was fully articulated, with air-operated pushrods, pittman arms, nitrogen cylinders for steam effects, etc. I did a bunch of work on this- mostly fitting valves, some forge work, hiding universal joints. Small bits and pieces.
Our other big project was for the rock crusher scene. The rock crusher was about the size of a dumpster, with two giant steel drive wheels on either side and eccentric arms that went up and down. The whole thing was driven by a variable speed DC motor on a large flat belt. It was “blown up” with compressed air mortars, which were air tanks with red hat solenoids fitted to them. I built three of these, and Bruno had a big four-foot tank that we also used. The tanks had big steel funnels that we fitted and filled with bits of broken cork (poor Talis had to spend days breaking up sheets of cork), peat moss, and movie dust. When we applied 12v to the solenoid, the valve opened up and emptied the tank within seconds, emptying the funnels and simulating an explosion without the need for black powder or det(onation) chord. It usually gets a little sound effects to cement the illusion. Of course, there are no flames with this type of explosion, but it’s a lot less risky.
I also did several days of detail work on the rock crusher, but with the way it had to be positioned on the set, none of it was visible on camera.