There are over 70,000 structures across Britain’s railways that Network Rail is responsible for maintaining. Chris Davies is HM principal inspector of railways and Steven Dennis is head of asset management at the Office of Rail and Road These include bridges, retaining walls, culverts and tunnels; with many dating back to Victorian times. Failure of a structure can lead to catastrophic risk to trains or in the surrounding area. The challenge is clear, and that’s exactly why a clear, robust and systematic examination routine is vital to monitoring the condition of structures. Without these examinations, the condition of assets is not fully known and faults may be undetected or not competently assessed, posing a potential safety risk.