Definition of penstock in US English:



  • 1A sluice or floodgate for regulating the flow of a body of water.

    • ‘To prevent landslips, the tunnel roofs have been rock-bolted and short-creted, and 7,000 steel liners used for pressure shaft and penstocks alone.’
    • ‘The work will involve the construction of maximum strength earth embankments and masonry walls along the Derwent, as well as the installation of floodgates, penstocks and flood valves.’
    • ‘A spokesman for the agency said the penstock sluice gates were opened after the last bout of flooding to allow trapped water to return to the river, but after an ‘oversight’ they were left open.’
    • ‘These schemes made use of the flow of water through a series of reservoirs, tunnels, penstocks and power plants.’
    • ‘Its massive, black iron penstocks and 30-ton generators sit just as they did when the powerhouse opened, as if waiting for the switch to be thrown again.’
    1. 1.1 A channel for conveying water to a waterwheel or turbine.
      • ‘We are now putting down pedestals where the penstock pipes will be laid leading to the power house.’


Early 17th century: from pen (in the sense ‘mill dam’) + stock.