Durham – Freeman’s Reach Archimedes Screw Protective Curtain

22 Apr
                         

Over recent weeks many of you will have seen the plastic protective curtain installed by Durham County Council, the screw operators. The purpose of this curtain is to help protect any jumping fish from damage caused from striking the rotating blade. This curtain comprising of a number of black vertical plastic slats was a “proof of concept” installation with the plastic slats fastened to the wire cage by cable ties. A permanent curtain has now been installed comprising of two layers of black plastic slats; a longer front layer and a shorter, 300mm, rear layer. This rear layer is about 30mm in front of the blade. In low water both slats hang vertically down whilst in higher water the front flap will be swept forward by the water leaving the shorter rear curtain to hang vertically down to protect jumping fish form striking the blade. In addition two underwater cameras have been installed to help monitor the behaviour of any fish entering the chamber. The attached photograph shows the new screen, and yes, all you can see is a black ”wall” in front of the screw, this is the curtain.