Forebay Green Water And Ice Racks Nov 23, 2006
One of the most significant challenges with a hydro-electric power station in a cold climate is ice.
There are two keys issues to worry about:
- A buildup of ice can prevent enough water from entering the penstocks, thereby preventing the turbines from rotating at an optimal speed
- Large pieces of ice can enter the penstocks and damage the turbines
Stopping ice from getting in
Ice management was a key requirement at Rankine and there were a variety of steps taken to address it. The angled racks inside the forebay are metal channels that try to prevent large pieces of ice from entering the penstocks. There are smaller ‘junk racks’ that can be lowered to prevent additional debris (garbage, tree branches, etc.) from the entering the penstocks as well.
Breaking up ice dams
Outside the forebay the ice could sometimes build up in significant ways that required it to be cleared. Workers would operate a boat outside the forebay that would be used to ram, breakup and dislodge ice buildup. In some cases this also involved using explosives to break up the ice.