||Test Van, Type 1 (Karrier)
||Cable Testing Van on Karrier Lilliput
|Fleet Number Ranges
||U66711 to U66725 (OXN 338 - 352) 1954
U79248 to U79271 (SXH 626 - 649) 1956
U80901 to U80904 (TGC 660 - 663) 1956
U80905 (TGC 665) 1956
U80066 to U80070 (TGC 824 - 828) 1956
U87806 to U87821 (447 - 462 CXY) 1961 (Mann Egerton)
U96598 to U96604 (988 - 994 FYM) 1963 (Harrington)
|Date of picture
General description of facilities
This vehicle has a forward control cab equipped with seating
accommodation for three passengers and a driver, under seat lockers and two
under floor compartments for the storage of a Generator, Reed Hummer and the
vehicle tool set. A sliding door separates the cab from the body which
is fitted with thermal insulation, side windows, roof ventilators, cable
access flaps on either side of the rear door, a paraffin heater with an
external flue (see H 0030), lockable cupboards, interior lighting, apparatus
benches, a 12V d.c. power supply and floor-mounted lashing anchorages.
Two skirting lockers are provided on the near-side of the body for the
storage of petrol and paraffin containers and an off-side skirting locker is
provided to accommodate the spare wheel. A detachable towing fitment
provides facilities for towing a trailer tool cart when necessary.
This vehicle is intended for use on cable balancing duties and, because of
the expensive interior fittings, it should not be used as a general stores
Taken from - ENGINEERING INSTRUCTIONS, TOOLS & TRANSPORT,
VEHICLES, N 3080 (Issue 1, 23.11.66)
Side view showing the petrol and paraffin locker open.
The flaps at the rear are cable entry points.
Cab interior with passenger seat raised and "Reed Hummer
A New Cable Test Van
By G. Slater
Taken from the POEE Journal Volume 47 October 1954
The author describes a new cable test van which gives
improved accommodation for test equipment and facilitates testing operations
in the field. An important development is the inclusion of a satisfactory
heater unit for maintaining suitable atmospheric conditions within the van.
The Test van was one of the first, if not the first, of the motor vehicles
in the Engineering Department fleet, excluding, of course, one or two
passenger cars, and a brief reference to the original test van which was
brought into service some 40 years ago will serve as an appropriate
introduction to the subject.
This vehicle, shown in Fig. 1, was obtained in 1914 for the Research Section
for the purpose of testing telegraph and telephone underground trunk cables,
and no doubt the testing of the London-Birmingham-Liverpool trunk cable laid
in 1914-15 was one of the main factors in mind at that time.
In 1919 only two test vans were in operation, but with the development of
the underground cable trunk network and the devolution of cable testing and
balancing from the Research Section, the number had increased to 14 by 1927
and to 29 by 1935. To-day the Department has in service some 70 test vans,
one of which is shown in Fig. 2, and except for changes in chassis types and
methods of body construction, no major changes in the layout of the vehicle
have occurred over a period of some 25 years.
|Fig. 1. The First G.P.O. Cable Test Van; Built
||Fig. 2. Type of Cable Test Van in General Use
That improvements were necessary to facilitate testing
operations was apparent as far back as 1938, and immediately prior to the
war a redesign of the test van was commenced. The development had then to be
suspended for the duration of the war, and although work recommenced in the
immediate post-war period, material and financial restrictions made progress
slow. The maintenance of existing test vans in service much beyond their
normal period of service was therefore necessary.
Features of the New Test Van
The provision of a dry atmosphere inside test vans to ensure that the
electrical insulation of the apparatus is maintained at the level necessary
for accurate testing has always been a difficult problem. Various ways of
disposing of condensation on the apparatus have been resorted to in
practice, none of which was really satisfactory. The locations in which test
vans operate preclude the use of mains power for electrical heaters; heaters
which are dependent on heat derived from the vehicle engine are also
precluded, since the vehicles are required to be stationary for very long
periods during the testing operations and to run the engine during these
periods would be costly. The use of heaters independent of mains supply and
the vehicle engine, such as the usual type of paraffin heaters, has the
disadvantage that the combustion products project additional moisture into
the atmosphere of the van, thus tending to defeat the object of disposing of
the condensation inside the vehicle and on the testing apparatus. A
catalytic heater has also been considered. This flameless heater, using
petrol as the fuel in conjunction with a platinised asbestos pad, proved to
be unsatisfactory in operation as it produced carbon monoxide.
A means of producing the required atmospheric conditions was eventually
evolved at the Research Station, using a paraffin heater, and a specially
designed flue to carry off the products of combustion to the outside
atmosphere. Heaters of this type have now been incorporated in the design of
the new test vans (Fig. 3) recently put into service and have also been
fitted to all existing test vans which have a reasonable length of unexpired
Fig. 3. The New Cable Test Van
The chimney is for the rear compartment heater.
Fig. 4. Interior View of New Cable Test Van Showing Heater and Flue
The heater, fitted in the body of one of the new vehicles,
is shown in Fig. 4. It consists of a heavily constructed fuel container with
a capacity of 1 gallon, which is sufficient for 16 hours’ burning. A double
gauze cylinder surrounds the chimney of the heater which is housed
a baffled flue, rectangular in shape and constructed of aluminium alloy. The
flue terminates on the outside of the vehicle in a cowl which effectively
prevents down-draughts. The heater is capable of producing some 10,000 B.T.U.,
equivalent to 2.9 kW per hour. The fire risk has been reduced to a minimum;
indeed, the heater may be left burning whilst the vehicle is in motion and
in garages overnight, thus ensuring a body interior free from condensation
in readiness for the day’s testing operations. The fuel supply for the
heater is carried in two 1 gallon cans which are accommodated in a locked
compartment situated outside the vehicle on the offside beneath the floor.
A feature which has been introduced, but which is not obvious from the
appearance of the vehicle, is greater heat insulation of the vehicle body
effected by the use of a heat-insulating material packed in the space
between the outer aluminium alloy and the inner plywood body panels.
Ventilation is controlled by adjustable louvred vents at floor level and
ventilators in the roof, which, together with the improved type of
adjustable side windows, should ensure adequate natural ventilation
reasonably free from draughts.
The rearranged benches provide adequate space for the testing gear and have
been simplified by dispensing with the folding facility which, it was found
on investigation, was rarely used. The fence rail at the edge of the benches
has been improved. It is now produced in light alloy and arranged in
sections to facilitate raising and lowering. This, it is hoped, will be of
considerable advantage when it is necessary to dispose of the uncomfortable
ridge when a section of the bench is used for writing purposes - a
discomfort which was often endured in the old vehicles because of the
awkwardness of lowering the one-piece rail.
The bench tops have been finished in green linoleum and incorporate the
necessary test lead holes and a cable entry flush-fitting flap.
Beneath the benches two cupboards have been arranged, one at the rear of the
offside with a hinged door, and one with sliding doors towards the nearside
forward end of the body. The cupboards are fitted with adjustable shelves
and provide adequate space for stowing equipment. The wheel arches have been
squared off and fitted with fence rails to provide additional under-bench
Above the offside bench a light alloy rack extending practically the whole
length of the body affords convenient accommodation for storing test sheets
and the records associated with testing operations. The edge of the rack is
padded to provide protection for the head in the event of accidental contact
whilst moving about the vehicle.
Interior lighting is provided by battery-operated pendant-type lamps
arranged above the benches and a roof light above the rear step. The sets of
lights on either side of the body are controlled by separate switches placed
at the forward end of the body and the step light by a switch conveniently
placed adjacent to the rear door. On each side of the vehicle, immediately
above each bench, a conveniently placed plug socket gives access to the 12V
battery supply for testing purposes and, should it be necessary, for a
portable bench light.
The provision of ring bolts in the floor, apparatus-securing straps on the
benches, and concertina-type blinds to the windows completes the internal
equipment of the body of the vehicle, which is finished in green and cream,
giving the whole a pleasing appearance and a serviceable finish.
Fig. 5. Built-In Steps at Rear of New Cable Test Van.
The slotted blocks either side of the rear door are attachments for a tow
Access to the rear of the vehicle, which incorporates a
full-width sliding window in the door, has been considerably improved by the
introduction of a built-in step (Fig. 5) which, when not in use, folds into
the body of the vehicle. On either side of the rear door two cable entry
traps give access to the interior of the body.
The forward control chassis on which the vehicle is built enables much
improved cab accommodation to be provided. Seating for four persons,
including the driver, is available; bucket-type seats for the driver and the
front passenger and a bench seat, facing forward and located on the offside
of the cab, for the rear passengers. The driver's seat is adjustable for
height and in the forward and rearward directions. A view of the cab is
shown in Fig. 6. Beneath the rear passengers' seat are two spacious lockers,
which are independently locked, providing ample personal locker space and,
if required, additional stowage space for equipment.
Fig. 6. Sliding Door Opened to show Interior of Cab of the new Cable Test
Access to the body of the vehicle from the cab is by means
of a sliding door (Fig. 5) which is fitted with a Yale type of lock to
ensure the security of the contents of the body when the vehicle is left
unattended in garages with the cab doors unlocked. A sliding glass panel
fitted in the bulkhead partition provides a clear line of vision from the
cab, through the body and the large window in the rear door, to the rear of
the vehicle. The two 12-V vehicle batteries, provided to cope with the heavy
lighting load which occurs when testing operations necessitate the interior
illumination of the body, are located beneath the cab in an under floor
locker, access to which is obtained via a floor trap secured by a budget
Accommodation for the Generator No. 2 (Reed Hummer) is provided in a
compartment also beneath the cab floor immediately below the front passenger
seat. Access to this locker is obtained through a floor trap uncovered by
tipping the passenger seat forward. The compartment is felt-lined to provide
a reasonably soundproof housing for the Generator No. 2, and has been
located in this position so as to be as remote as possible from the test
benches within the body of the vehicle. Wiring for connecting the generator
is terminated inside the compartment and extends in conduit to a terminal
block mounted above the offside test bench.
The vehicle tools, with the exception of the jack handle, are accommodated
in another under floor locker beneath the driver's seat, access to which is
gained by sliding the seat forward. The jack handle is housed on the rear
passengers' seat supporting rail where it is secured in position by two
straps. Two coat hooks, one on either side of the sliding door aperture, and
a light for illuminating the cab complete the cab facilities. Access to the
cab is gained by a flush-fitting sliding door on the nearside and by a
hinged door for the driver on the offside.
To provide for towing a trailer tool cart a detachable towbar was specially
designed by the Motor Transport Branch. This towbar slips into two vertical
key ways fitted to the ends of brackets which are attached to the rear of
the chassis members. When not required the towbar is housed beneath the
chassis on the offside along with the spare wheel, access being gained by
means of a hinged flap which when closed completes a deep unbroken skirt
line for the vehicle body.
Mounted as it is on a well-sprung chassis with adequate shock absorbers, the
vehicle is considered to be a considerable improvement on the old type of
test van, and it is hoped that it will serve the users well.