During May safety critical components such as the draw hooks and wheelsets were carefully cleaned and NDT tested (Non Destructive Testing). This important procedure highlights any defects within metalwork that could later lead to failure of the part in service. Thankfully the majority of components passed the examination, however a number of brake block carriers failed and replacements duly sourced. When complete the carriage will have a dual (air and vacuum) braking system fitted, allowing it to be compatible with a range of heritage rolling stock. Interestingly, a number of ex London Underground A-Stock components have been recovered for re-use on the carriage braking system. Items include an auxiliary reservoir tank and two pressure gauges formally fitted to 6136 and 5136.
The profile of the wheels was checked last year and the shape found to be fairly good – A moderate amount of wear was discovered but well within intervention limits. There are currently no plans to re-profile the wheels (now close to P8) and they should be good for another 100,000 miles!
It can be very difficult to undertake an accurate and faithful restoration if original components are missing, or the information required to reproduce them unknown. One such challenge has been to identify the type of door latches once fitted to Met353. As none of the originals survived it was most fortuitous to recently find a complete door from another early Metropolitan Railway carriage, Met212 built by Ashbury in 1881. This has been kindly loaned to the project team by the Quainton Railway Society (QRS) and the detailed information gained from inspecting this example is proving invaluable to the build. After some careful cleaning and dismantling, it quickly became apparent the lock mechanism was designed by Edwin Robert Wethered, an inventor once based in Woolwich, London. It closely matches his patent: 407,268 submitted in 1889.
Notes: Met212 was one of the last 8-wheeled stock carriages to be operated by the Metropolitan Railway. It was later modified for use as a sleet clearing vehicle and survived into London Passenger Transport Board (LPTB) ownership in 1933. Once withdrawn from railway use, the carriage body was grounded next to staff allotments alongside Aylesbury train station. A door was rescued by QRS before the carriage was finally broken up in 1967.