steel monkey
n.— «This is where not being a sissy comes in. Steel monkeys as they are affectionately called, have to walk the steel girders in order to put the steel beams in place. They walk the beams a hundred feet in the air. One false step and it’s like trying to fly with one wing.» —“Galena Creek Bridge False Works Are Deceiving” in Galena Creek KOLO-TV (Reno, Nevada) July 31, 2008. (source: Double-Tongued Dictionary)