Mystery Work

From 1908, a stereograph of the construction of the tower of the Singer Building:

The title is accurate – “Four hundred ft. above the street – iron worker on the Singer Tower, New York, U.S.A.” but it doesn’t tell us what we’re actually looking at. For example, the steel we’re seeing is a bit weird. We’ve got a built-up box column with splice plates, ready to receive the next section up, with a large bracket on one side. But the built-up bracket has rivet heads projecting on its top surface, so it’s not going to be the seat for a piece of steel. Maybe to support masonry? On the right we’ve got a beam higher than the floor-level framing that the worker is sitting on, which is the cross-member for a bracing truss. The beam below at the floor level is two separate channels, with a gap between to allow the not-yet-erected diagonal bracing to pass through. For some reason, there are a series of closely-spaced beams on the left, with odd angled ends, possibly, again, to support ornamental masonry. The cityscape beyond is north of the building, so if this is framing for the north facade, some of this makes sense.

My big question is what that man is doing. He certainly is not driving rivets with that little hammer, and in that relaxed position. The picture could, of course be entirely staged, but most of the staged pictures I’ve seen make some pretense to show actual work. If this isn’t fake, my guess is that he’s performing quality control, checking the field rivets. I’ve never checked new rivets for soundness, but I’ve certainly used a hammer to check steel framing for deterioration: I’d guess that rivet that doesn’t fill its hole entirely sounds different when tapped than one that does, just as rusted steel sounds different than solid.