Extensive and complex repair work of Carlisle to Settle railway
Hanson Concrete worked with specialist contractor Story Contracting to tackle one of the biggest engineering challenges ever faced by Network Rail. A severe landslide at Eden Brows, Cumbria – caused by extreme weather conditions – resulted in the closure of the Carlisle to Settle railway for 14 months and led to extensive and complex repair works to safeguard the future of the line.
Eden Brows is close to two geological faults and the line is located 200m from the river Eden and 70m above on a severe incline. These factors, coupled with access issues, resulted in numerous complex engineering solutions having to be developed to execute a successful repair.
The initial phase of concrete repair works required the installation of 226 piles, 660mm in diameter and up to 20m in length, protected by a steel outer casing, placed with laser precision in two rows. Reinforcement comprised a cage consisting of B40 bars with 16mm links which were specifically designed for the project and weighed in excess of 2.5 tonnes each.
The concrete had to remain workable long enough to be delivered to the remote site in a highly fluid condition but, once placed and compacted, had to maintain structural stability with no excessive bleed, settlement or static segregation.