CONCERN over the foundations of three viaducts on two key lines spanning the River Eden has now resulted in the completion of protection work which has been ongoing for two years.
The erosion, known as scour, is caused by strong-flowing currents, however, increases in rainfall in recent years has sped up the scour to an alarming rate.
Long Meg viaduct on the Settle & Carlisle line is a 1940s-built concrete viaduct carrying the goods lines through Carlisle and an adjacent Victorian-built viaduct, and all have been badly affected, leading to the two at Carlisle on the West Coast Main Line being subject to a 20mph speed restriction.
Working with Environment Agency and Natural England, Network Rail used a detailed hydrographical survey of the riverbed that revealed how, over time, the water had scoured away the viaduct supports.