Mining Steel Structures: Conveyor Galleries, Transfer Towers & Process Plants A mining plant is a network of conveyor galleries and transfer towers, with the process buildings hung off it. Every mining steel structure on the site is designed from the process data rather than from a building code. Most of the steel goes into that network, and almost all of the difficulty does too: long spans, high supports, dust, abrasion and a site where the biggest crane may be the one you