During the late 1980's the London to Norwich services were electrified and upgraded by the use of Class 86 locomotives and push pull operation.

The author was involved with the commissioning of the DBSO's and the associated Time Division Multiplex (TDM) control system and was based at Norwich Crown Point depot.

The former Scottish region DBSO's  were hand-me-downs from the Edinburgh Glasgow services and were originally used with class 47 power. However they were then hard-wired with through control cables but following the cascading to Norwich they were upgraded and fitted with TDM through control for use with the class 86 locos - which of course had already been operating with the system on WCML.

One unusual feature of the Norwich services is the use of the locomotives at the London end whereas the class 91 and Mk4 DVT and the original WCML formations usually had the locos at the Country end.

They survived into 2006 working with the class 90's but were withdrawn in 2006 in favour of even more cascaded stock in the form of ex-WCML Mk3 DVT's - together with the Mk3 coaching stock.

After their withdrawal several DBSO's have been acquired by Serco for potential use with test trains and are to be painted yellow.

Click on the picture for a bigger image - photos are the author's unless otherwise stated.