Last week, TfL Rail completed a migration to running longer trains between Paddington and Reading.
When TfL Rail took over parts of the service from GWR ahead of the opening of the Elizabeth line, although it ran with Lizzie line trains, they were 7 carriages long rather than the 9 carriages that will be used when the Lizzie line opens fully.
They started swapping over to 9-car trains back in March, and starting from last (Monday 18th May), they’ve been using full-length trains and running a near full timetable on the line.
The 7-carriage trains are now being moved across London to replace the remaining 30 year old Class 315 trains that TfL Rail inherited from Abellio Greater Anglia in May 2015 on the Liverpool Street to Shenfield line.
The line between Liverpool Street and Shenfield will continue to use 7-car trains as the platforms at Liverpool Street station would need lengthening to accommodate the longer trains. When the Elizabeth line opens fully, then all trains will be extended to the full 9-car configuration, and Liverpool Street station platforms will be extended as they will be a reserve option for the Elizabeth line when needed.