Strainstall recently installed a rock fall monitoring system on a section of cliff face in Dawlish (near Exeter). Network Rail turned to Carrillion to develop a technical solution to the problem, and it was decided that rock netting, reinforced by vertical wire ropes, should be installed over the cliff face to hold the rocks in place. Strainstall Operations were then contracted to instrument all 57 of the ropes. 25 tonne load shackles and an accelerometer were attached to each one, which in turn were connected to a data logger system. The five data loggers are linked to a site computer, which ultimately links to the Exeter signal box via broadband, enabling the signalman to see when a rock fall has occurred so he can determine what action is required in accordance with the severity of the risk identified. This means that train speed restrictions are only imposed when there is a recognised measurable risk to trains, as opposed to the current blanket restrictions.

Ian Hobbs Technical Services carried out the complete Electrical Installation on the above project.