In October 2022, five tank wagons in a freight train transporting cement powder from Clitheroe, Lancashire, to Mossend near Glasgow, derailed close to Petteril Bridge Junction in Carlisle. A number of wagons were damaged and there was significant damage to the track and also to the bridge over the River Petteril. This resulted in the closure of routes from Carlisle to Newcastle- upon- Tyne and to Settle for a period of seven weeks. Thankfully, no-one was injured in the accident.

Emergency works included a programme of structural reinforcement to the existing brick arches of the rail bridge. A sprayed concrete solution was specified which included the fixing of reinforcing mesh and concrete encapsulation to a depth of 300mm.

The location of the site offered limited to no access for ready mixed concrete (RMC) wagons delivery, so shotcrete was rejected in favour of a dry spray application. Due to the depth of concrete, rapid set materials were required which allowed a greater depth of material to be applied at any one time without the danger of drop outs or the creation of voids within the concrete matrix.

This method also reduced the number of construction day joints and lent itself to a more monolithic layer of concrete, with only a short period of time (overnight) before the next application of sprayed concrete, through to final completion.

The use of two crews working extend shift patterns also shortened the emergency works programme and allowed for the concrete curing time to start and finish earlier than if it was applied by a single crew to allow the line to return to normal operation.