A Water Pump below Shoalsgate Station
This Water Pump can be seen in most factories and hydro-stations in Thief: The Dark Project/Thief Gold and Thief II: The Metal Age. It has the appearance of a slender tower encased in a metal framework with pair of antennae protruding from the top. It stands on a metal base with stout pipes on three sides, directed downward (usually into a pool of water). These devices do not have any visible moving parts and are often situated in bizarre locations. They are able to withstand intense heat, judging by one example at the KD Site placed in the centre of a pool of lava.
The objects themselves do not have large collision areas, and can sometimes be walked through. All of those seen in Soulforge Cathedral display this feature.