The below update was received from Network Rail regarding the bridge works:

The detailed assessment that was conducted by the Designers did not give confidence that work could continue as they could not identified all the void. As the bridge is listed, we [Network Rail] are limited with the investigations methods we can use e.g we can’t drill to on the bridge to check the extent of the voids. The Designers are planning for the Ground Penetration Radar (GPR) to identify the voids. Once all the voids have been identified, the Designers will recommend a solution for Network Rail to consider.