Placing foil on bed of water course - by fixing end, then paying it out from buoyant roll moving along surface as water is pumped onto foil

摘要

The arrangement is intended for placing a water-impermeable foil on the bed along a stretch of a water course. The foil is supplied off a roll (5) which can float in water. The start of the foil is secured at the beginning of the stretch and the two ends of the roll (5) placed on the crowns (7) of the banks (4). Water is now pumped on to the foil between the fixing points and the roll so that this rolls over the water surface whilst paying out the foil. At the end of the stretch the foil is again secured.