It was designed such that it could carry a pantograph but not under 25kV OHLE as it was originally not fitted with insulators on the roof, nor earthing straps etc. on the underframe and wheelsets.

The vehicle was equipped with an original compartment, a kitchen (below the flat roof area), a large instrumentation area, a generator compartment but no separate workshop.  It had no internal access to the flat roof.

The main instrumentation area had a raised dias from which any pantograph fitted to the flat roof area could be observed. Instrumentation including an on-board computer which had a large associated reel-to-reel tape recorder and punched card reader. It also had a teleprinter telex keyboard for communication with the computer.

It was used extensively in the development of the BR/BW high speed pantograph at the Old Dalby test track in the late 1970's, where it was used with HSFV4 on dynamic and static testing.

Although it initially retained its original BR1 bogies the vehicle was later equipped with a design of bogie derived from APT-E and was capable of being hauled at up to 125 mile/h. I only recollect this happening when it was paired with Lab 6 on a series of high speed tests in Scotland when investigating 2-pantograph operation using an HST set in June 1982. For this occasion the vehicle was modified for use under 25kV, with pantograph foot insulators and earthing bonds across the wheels and between the body and bogies.

It was also used together with HSFV4 when undertaking curving tests with HSFV1, fitted with Load Measuring Wheels, which took place initially in Cornwall and later on the Conway Valley line in North Wales in October 1976.

The vehicle was taken to GC North at Ruddington after being stored at RTC out of use for many years and was photographed there in August 2012 (see below) but by November 2013 it had been scrapped.

Click on the picture for a bigger image - All pictures are the author's unless otherwise credited