Crane and hoists keep dam dry26 May 2009
The installation is part of a programme to renovate and raise the dam road in order to protect it from flooding. Using the radio-controlled hoists and the crane, two operators are able to isolate the dam in less than four hours by placing cofferdams upstream.
The VT4 hoists have been used in tandem with two fixing points each to stabilise the cofferdams during lifting.
Lifting equipment firm Meije installed the system, and also devised an automatic release system for when the cofferdam is in place. This uses a fixed lifting beam with two lifting hooks. A balance triggering mechanism activates a counterweight that trips a lever and unhooks it from the cofferdam.