The power signal box at New Street was completed in 1964. It is a brutalist building with corrugated concrete architecture, designed by John Bicknell and Paul Hamilton in collaboration with William Robert Headley, the regional architect for British Railways London Midland Region. The four-storey structure is at the side of the tracks connected to Navigation Street. As of 2020, it is a Grade II-listed building. Until recently, two small sidings (Nos. 2 & 3 Engine Sidings) were located in front of the signal box which were used for stabling electric locomotives in connection with locomotive changes from diesel to electric traction on XC services heading north. As they are no longer needed these have now been removed in connection with the ongoing resignalling project for the station area. No.1 Engine Siding was located at the north end between Platforms 4 and 5 and was lengthened some years ago to form Platform 4C