In 1975 a Mk1 BSK coach W34875 was
converted into an electrical systems test car at Swindon for the R&DD.
Known as
Lab Coach 6 and numbered RDB975422, it was utilised for main line OHLE tests by the R&DD
Electrical Engineers Section and originally based at Rugby but was
eventually transferred to RTC Derby.It was
designed such that it could carry a pantograph under 25kV OHLE and was
fitted with insulators on the roof and earth brushes on the axles.
The
vehicle was equipped with a conference area and kitchen (below the flat roof
area) a large instrumentation area, a generator compartment and a separate workshop.
It had a vertical internal ladder situated between the kitchen and the
instrumentation area which accessed the flat roof. This was via a hatchway
which was locked and the key was only available via a safety control
procedure for use under 25kV OHLE.
The main instrumentation area has a
raised dias from which any pantograph fitted to the flat roof area could be
observed. Instrumentation including a large speedometer was also fitted on a facia below the window which was
fitted with strengthened glass.
The vehicle was also equipped with Mk3
(BT10) bogies and was capable of being hauled at up to 125 mile/h. I only
recollect this happening when it was paired with Lab 1 on a series of
high speed tests in Scotland when
investigating 2-pantograph operation at using an HST set in June 1982.
However it may have been tested at these speeds when new.
After the purge of the R&DD in the late
1980's the vehicle was transferred to the DM&EE and re-named as Test Car 5.
Unfortunately it did not fit into the plans of the DM&EE and was often used
as a make-up vehicle although it did find use during the class 89 testing.
During the 1990's it was allowed to deteriorate and was eventually withdrawn
from service.
After having its equipment and bogies
re-claimed for further use the vehicle was scrapped in 2007.
Click on the picture for a bigger image - All
pictures are as credited
