Bedford Boat Slide - Archimedean Screw Turbine - Opening - The mechanism that controls the inlet of water to each of the 2 turbines.
<a href="//commons.wikimedia.org/wiki/User:Simonxag" title="User:Simonxag">Simon Speed</a>
2012-06-18
<span class="int-own-work" lang="en">Own work</span>