The series was retained by the Southern Region of British Rail, but amended so that the numbers carried a 'DS' prefix instead of an 'S' suffix.
In 1952, the Eastern Region of British Railways introduced its own series for departmental (non-revenue earning) vehicles, including locomotives.
Also included on this page is a former diesel locomotive that had been converted as a mobile power unit and numbered in the 9xx block used for miscellaneous vehicles.
The London Midland Region Engineering Department numbered its diesel locomotives in a series running from ED1 upwards (though ED8 and ED9 were never allocated).
Details of all locomotives are shown below: Internal User vehicles are those that are not allowed to run on the mainline, but are only for use within depot complexes.
Two former locomotives that were heavily stripped, leaving just the frames, to carry power units within Toton depot were allocated IU numbers.