Vintage work crew photos

[Frank S]

Riggers riveting the red-hot rivets on the lower outside south chord, Sydney Harbour Bridge, 1930-1931 / Sam Hood.

How are these rivets kept ´red hot´ for this operation?

Actually the rivets were heated on site as needed, in the early days they would have used small 17" diameter coal forges in more modern times they would have started using cylindrically shaped propane forges much like several knife makers use . Even more modern way of heating rivets on site is by induction coils. Induction coils can heat as rivet in seconds simply by passing the rivet through the high energy field.