Work begins on 140-year-old structure

and prepared sections of the structure around the bearings in readiness for jacking-up for the work – with the first bearing set to be removed on Saturday, September 1. Work will be ongoing until December and delivered with no disruption to train service.

The weight involved means that a bespoke system of getting the bearings to and from the bridge then up onto the structure needed to be developed, using a motorised all-terrain pallet truck and a pulley and rail system to move the old bearings out and the new ones into position.

As well as the logistical challenges of working at height above a river, the Network Rail team and specialist contractor Taziker also have to work within the restricted space under the bridge deck to firstly insert hydraulic jacks to take the weight of the bridge and raise it a maximum of 5mm. The bolts will then be drilled out and the old bearings removed and replaced.

One bearing will be removed and replaced at a time over the next 12 weeks, with three of the 12 only able to be replaced when the line is closed. The other nine will be removed and replaced while trains continue to run above.

Mr Spence added: “Every bridge we work on has its own set of challenges, but replacing bearings on this type of structure within the constraints of the railway environment is unique; logistics, engineering, the physical size of the space we have to work in and the sheer weight of the bearings going in and coming out.

“Add to that the element of the unknown in how a century-old bridge deck will react to being jacked and how easily, or not, the bearings will be removed, has certainly focussed minds on this task.”

The scaffolding will be removed and the site cleared by December 2018.