Metropolitan Line S Stock units withdrawn
A special timetable was applied to the entire Metropolitan Line during April, due to a need to withdraw numerous S Stock units from passenger service. This was not a common issue across the Bombardier-built S stock trains that operate across the other subsurface lines of the Circle, District and Hammersmith & City lines. Rather, an incorrect calibration setting as Metropolitan Line train wheels passed through the wheel lathe at Neasden depot is reportedly the cause.
Normally units pass through the lathe on a programmed basis at around 200,000-250,000 km. This equates to once every 18 months.
If an incorrect setting has been applied, this may mean that another pass through the lathe is required. However, the withdrawal of the trains from passenger service suggests that this wasn’t possible, meaning that the wheels need to be scrapped. As a result, new wheelsets need to be delivered, fitted to bogies which, in turn, are reinserted underneath cars, so that units can re-enter service.
Including the S7 train, that has an additional car inserted into it to make it up to an eight-car unit, there are 59 trains that serve the Metropolitan Line. With only 31 trains available at one time, the introduction of the special timetable meant that some stations in the outer suburbs were only served once every 30 minutes. As RE went to press, around 41 trains were expected to be available by the early May bank holiday.