Cookin' rivets. As a crew of riveters works to fasten a new smokebox to a boiler under overhaul, a female colleague is busy heating the rivets and transferring them to the work site. In this scene, she uses a pair of tongs to grasp a white-hot rivet and remove it from an electrical resistance oven. On the right side of the oven, another fresh rivet is already in the process of being heated up.
There are a number of ways in which steel rivets like these can be heated for use. One way is to use an old-fashioned forge, with a blower and glowing coals. Another is an induction oven. The arrangement in use in this photo is an electrical resistance oven. It's a remarkably simple apparatus that heats the rivets by passing a high-amperage, low-voltage current through it. When you were young, perhaps you experimented with cooking hotdogs by putting two stout nails through a board and fastening each of the nails to one of the two conductors on an electrical cord. The hotdog is impaled on the two nails and cooks pretty quickly. Well, this oven works pretty much the same way. Each rivet is held in place by spring-loaded copper blocks on the top and bottom, which provide the conduit for the electrical current. It takes just a minute or two before the electrical energy has the rivet glowing white-hot. Just before we began this photo session, our Safety Advisor from the Strasburg Rail Road briefed us on the various hazards to look out for in the shop building. He spent more time talking about this oven than anything else, and warned us that accidentally backing into this unit while taking a photo would likely be the LAST photo the person would ever take. After listening to his dissertation on the oven, I pretty much didn't want to be in the same room with the thing. Fortunately, our "Rosie" here was quite a bit braver than I. She's a member of a World War II re-enactment group, and pretty used to being around hazardous equipment.