UK: A National Incident Report issued on January 10 confirmed that hairline cracks have been found in the T slots of eight of 75 MkV coaches in the Caledonian Sleeper fleet at points where the yaw damper bracket joins the body of the vehicle.
Industry sources report that cracks have since been identified on a ninth vehicle.
The coaches with cracks have been stood down and will not re-enter traffic until suitable mitigation is in place.
The NIR notes ‘the initial instance on 15004 appeared to show impact or tooling damage on the T slot but all other vehicles show no sign of any similar discrepancy’.
It has been confirmed that the defects arise from issues previously identified on other CAF rolling stock fleets used in the UK. The NIR notes that additional checks have been carried out on the Caledonian Sleeper fleet in the yaw damper and anti-roll bar region since April 2021. These include a monthly visual check of the T slot, and a detailed measurement campaign which arose from an earlier NIR covering the similar MkVa loco-hauled coaches to provide greater clarity on vehicles at higher risk of cracking.
The timing is unfortunate for CAF as these cracks have been discovered before the completion of the testing and validation of long-term mitigation, already underway, which involves a redesigned attachment method.
A similar modification programme was carried out on earlier Class 19x and Class 331 multiple units after cracks were discovered on a number of Class 195 vehicles in 2021. Following this work, CAF stated that it had identified the root cause of the problem and the solution had been implemented across several fleets.
