TRANSPORT for London’s (TfL’s) decision to go ahead with the introduction of fully automated signalling north of Finchley Road on the Metropolitan Line, part of the Four Lines Modernisation programme (4LM), could create challenges for future heritage stock operating on London Underground (LU). The planned modernisation includes sections of track currently commonly used by heritage traction, between Harrow-on-the-Hill and the termini at Watford, Amersham and Uxbridge.
When the 4LM project was initially planned, all sections of the Circle, District, Hammersmith & City and Metropolitan Lines, LU’s Sub-Surface Railway (SSR), would be fitted with automatic signalling.
