noun. Primary gate or valve at aqueduct or other source that can be opened or closed to regulate the flow of water entering an irrigation system (of lesser gated canals and irrigation ditches).

noun. A moveable framework designed to hold still the heads of cattle for various procedures

"At about the same time, a call may have been put in to the longwall headgate controls, where someone removed power from the longwall and at the same time disconnected the water sprays."