What is a Steel Yard OTH?
a big, currently unused radar
crater after detonating a nuclear bomb
organization of secret Russian agents
Duga (Russian: Дуга) was a Soviet over-the-horizon (OTH) radar system used as part of the Soviet missile defense early-warning radar network. The system operated from July 1976 to December 1989. ... NATO military intelligence had already given it the reporting name STEEL WORK or STEEL YARD.