A requirement at a headwall can be to vary the amount of water let through into or out of the watercourse or to stop it altogether.  In order to do this we can fit a Penstock to the Headwall.  Penstocks can be supplied manufactured from Ductile Iron, Stainless Steel, HDPE or Composite.  Penstocks, or as they are sometimes referred to, sluice gates, are used to isolate or control flows.  The Penstock consists of a sliding door controlled by a mechanically operated spindle, which moves over an aperture in a frame, which in turn is secured onto a structure. Much like the Tilting Weirs the Penstock can be fitted directly to the Headwall or alternatively in a chamber directly behind the Headwall.  The Penstock can be manually operated or mechanically actuated.  The choice of Penstock depends on several criteria, amount of pressure involved, on-seat and off-seat, size of opening, direction of flow, method of mounting i.e. channel, wall, pipe or thimble and method of operation.  If the unit is going to be fitted to one of our Headwalls and access is required to operate the Penstock, walkways and handrails can be designed into the structure.