The package of works designated by London Underground as ‘Operational Segments 4 & 5' (OS4/5) consists of alterations to the position of existing signalling equipment to allow the introduction of the new S8 rolling stock prior to the main Sub Surface Railway Resignalling.

The work will take place between Aldgate in the east of London, through major interchanges such as Liverpool Street and Kings Cross finishing at Euston Square; there is also the potential for additional work to be awarded at Finchley Road and Neasden in North West London.

This is a significant package of works as it is the first pure signalling contract to be awarded to VolkerRail by London Underground and represents a major step into a new market sector.