MCR21 was the third unit of ten to be built to an exacting BBC specification. The coachwork was by Marshalls of Cambridge and the technical installation was by Pye. It was first registered on the 12th of November 1963 as 388 EXH.
These ten Outside Broadcast units, the “main fleet scanners”, formed the mainstay of the BBC’s fleet in the middle 1960’s until the advent of colour TV.
Seven were allocated to London One each to Cardiff, Bristol and Glasgow
A note about the BBC’s numbering scheme. The first OB vans or scanners were built before the war and these were MCR1 & MCR2. After the war the numbering was continued to MCR28 which was the last monochrome scanner. With the advent of colour the BBC started the sequence again at 1 but this time with a “C” prefix, so the first colour scanner became CMCR1 and so on.
In addition to the MCR & CMCR numbers there was a “fleet number” this was composed of a letter, from the first letter of the chassis manufacturers name and the three numbers from the registration number. So the fleet number for MCR21 was C388.
If this was not enough there was also a local number, This number tended to change and could be allocated to different vehicles at different times or locations. MCR21 was variously know as:-
Unit 1, LO1, and LO21. It may be of interest to know that over the years there has been at least 4 different vehicles known as LO21. MCR21 was the first!
Overview of the vehicle data:-
Registration Number 388 EXH was first licensed on 12 Nov 1963
Commer Chassis C76Z with a six cylinder 4.9lt. petrol engine, 4 speed gearbox, vacuum servo brakes. 5 doors and skirt lockers around the sides. Air conditioning unit to the rear. The roof is decked with teak planking and there are 3 roof extractor fans. MCR21 is 24′ 8″ long, 11′ 9″ tall and 8′ wide.
Workshop Manual for 6 cylinder O.H.V. Under Floor Petrol Engine. engine-handbook