Test Car 4

In 1961 the BR Western Region out-shopped their new Dynamometer car DW150192. It had been converted from a 1947 Swindon-built  third class corridor carriage to a design by F W Hawksworth, on lot number 1691 and originally carried the number W796W.

It is rumoured that the donor vehicle was involved in the Milton derailment of November 1955 and that's why it was chosen for conversion. What is recorded is that it was withdrawn as condemned stock in August 1958 and took three years to convert.

There were articles in the railway press at the time of its out-shopping as a Dynamometer Car.

Click the link!

bulletA NEW Western Region dynamometer car. Trains illus.,1961,l4, 498-9.3 illus., plan
bullet NEW dynamometer car for British Railways. Rly. Mag., 1962, 107, 460-5. 4 illus., plan. diagr.

As new

Pictures below are BR official unless otherwise credited

WR Dynamometer car ex-works  WR's new Dynamometer Car pictured here when freshly out shopped at Swindon in 1961. WR Dynamometer car ex-works It was built as a Third class corridor coach in 1947 but was withdrawn from service by 1958 and extensively converted to become the BR Western Region Dynamometer Car, renumbered as DW150192.
WR Dynamometer car ex-works Another view of Swindon's craft work when new. Unfortunately all these views are from the same (corridor) side Marylebone The Dynamometer Car was exhibited along with a number of locomotives at Marylebone Goods yard in June 1961 - corridor side again!

Ron Fisher

Inside Inside the working end of the car - note the centre console at the rear and a couple of portable instruments on the Dexion tables which appear to be associated with diesel traction fuel consumption.

The X-Y plotter was behind the ribbed cover and the gauges would be brake pipe pressure, drawbar pull  etc with the speedometer in the centre. Two chart recorders were built into the rear face of the console. Later in life this area would be filled with 19 inch racks of equipment, tape recorders etc as the vehicle ceased to be a Dynamometer car and became a mobile laboratory

After its retirement it was bought by Alan Civil and he wrote a small paperback book in 1985 - now out of print

Western Region Dynamometer car

THE WESTERN DYNAMOMETER CAR by T. D. A. Civil-  44 pages.

It was equipped with various pieces of measuring and recording apparatus including a system from the road wheels to accurately record speed and distance travelled. Also included were

bulletchart table incorporating XY plotter
bulletlarge speedometer, brake pipe pressure gauge, brake cylinder pressure etc
bulletstrain-gauged drawbars (various)

Whilst based at Swindon the car was used extensively on testing numerous improvements to existing steam locos - such as the double-chimneys on the Kings and also on the new prototype main line diesels.

The BR Diagram book entry for the Dynamometer Car - click here for a bigger version

 Interior layout as I remember it in the 1970s


The generator room had a diesel generator which produced power for the coach and instrumentation. Although it had an electric starter motor it also had a crank handle which could be engaged on the crankshaft from the outside of the vehicle in case of difficulty in starting. Problem was if the coach was not alongside a platform it was virtually  impossible to reach and turn the handle.

In the late 1960s the car was transferred to the DM&EE's Testing Section at the RTC Derby along with other regional vehicles.

I worked on the Stress & Vibration Section of the Testing & Performance department who used this vehicle, between 1971 and 1974..

I remember a few tests where we used the Test Car,

bulletED generator mounting tests
bulletEdinburgh-Glasgow push-pull trials
bulletLowliner container wagons riding trials
bulletClass 86 tyre shelling tests
bulletHigh speed dipped joint tests at Cheddington
bulletFreightliner LMW tests
bulletLMW on class 86
bullet110 mile/h B4 bogie trials

I'm sure there were more but I forget. Here are a couple of anecdotes from those days

bullet I remember after a crew change during the day at Cheddington that the new driver was not told to keep the speed down to 125 and we set off touching 130 mile/h before it was brought back to the required speed.

During the course of the 110mile/h B4 bogie tests one of the plain bearing axleboxes on Test Car 4 failed. The lower oil reservoir casting became detached and fell onto the ballast, shattering and sending pieces everywhere. Several hit the Test Car breaking the window, showering me with glass and cutting me about the face. We limped back to Crewe and dumped TC4 in the ex-LNWR carriage sheds. A few days later we returned and transferred the coach back to Derby with the bearing wrapped in oil soaked cloths with frequent stops to check the axlebox temperatures.

After de-commissioning, the vehicle was purchased privately for preservation in 1983 and moved to the Foxfield Railway the same year, but was subsequently sold to the group restoring BR 4-6-2 71000 "Duke of Gloucester", as a support coach and fully restored as a Dynamometer car. It was put to good use behind the Duke on more than one occasion but not for long and is currently resident at West Coast Railways, Carnforth.

Unfortunately it has been stored outside at Carnforth since 1994 and is in a poor state of repair

Diesel testing on WR

Western on test D1029 passes Didcot with the Dynamometer car in June 1964

G Evans

On the Lickey

A shot of the Brush prototype locomotive 'Falcon' on the Lickey Bank with a 600 ton test train in February 1962

Brush Traction

Falcon Prototype Brush diesel No:1200 'Falcon' with the Western Region Dynamometer Car in chocolate and cream livery somewhere on the old GWR in February 1962. On the completion of the RTC and the formation of the DM&EE the vehicle was transferred to Derby to become Test Car 4.


Where is this? Pictured on Dainton Bank, the dynamometer car in use with a Brush Type 4 locomotive in 1962

Brush Traction

Lion Prototype BC&W diesel No:D0280 'Lion' with the Western Region Dynamometer Car in chocolate and cream livery just north of Bromsgrove Station at the bottom of the Lickey Incline in August 1962

AEI/Brian Webb Collection

RTC Derby

Freightliners In December 1969, the vehicle was still in WR chocolate and cream livery and is pictured here behind a class 45 and a couple of Mk2s heading south near Ratcliffe power station with Freightliner vehicles on test

David Ford Collection

Cargo Fleet The Western Region Dynamometer Car, not yet re-painted, is in this torpedo wagon test train at Cargo Fleet, Middlesbrough on 7th August 1969
Rugby Test Car 4 at Rugby on Freightliner LMW tests in September 1972


Beattock On May 3rd 1973 locomotive 86202 is pictured at Auchencastle with a 600 ton test train including the ex-Western Region dynamometer car (now Test Car 4) and banked by Class 85 E3082

Derek Cross

Cheddington tests 1971  A group of engineers in Test Car 4 during the May 1971 high speed tests on WCML. Note the wood grain veneer on the walls, the speedometer above the door and the modern instrumentation. This latter includes the 19 inch rack full of amplifiers plus a Southern Instruments UV recorder. This view is looking towards the vestibule in the main saloon.

Pictured here from L to R 'unknown' (possibly local LMR staff from Euston), Bob Morton, Herbert Titchener ('Titch'), Paul Moseley (in doorway) and seated at desk Don Dummer and Cliff Belfield seated against the vestibule.

Cheddington high speed tests 1971 The main control panel above the chart recording table showing the speedometer, brake gauges etc - this was a separate fitment in the main saloon and comprising the  chart recording table as well as the ingenious XY plotter. This photo was take during the high speed testing at Cheddington on WCML in May 1971 with the needle off the clock.
Crewe Now in red and blue and carrying the Test Car 4 branding, it is pictured at Crewe Basford Hall with a test train in April 1973.

It became Test Car 4 in the early 1970s and was re-painted from chocolate and cream to blue and red, much to the disgust of the ex-Swindon engineers.


EDU Test Car 4 pictured in the EDU being rigged for a test on 2nd April 1982. Note the 27-way cabling over the roof which was added when the vehicle was marshalled in a push-pull set on the Edinburgh-Glasgow service test train in 1972.

Colin Marsden

With 71000 'Duke of Gloucester'

See the Duke's website here

Test Car 4 pictured on the North Wales coast behind class 8P Pacific No:71000  'Duke of Gloucester' n the mid 1980s.

Andy Duncan

Stretton Derbyshire in the 1990s

Richard Bradley

Second version

The second Test Car 4 was a Mk3 coach which was originally part of the prototype HST (originally E10000 then W40000).  It was converted at Derby by the R&DD and became Lab Coach 15 'Argus'. When the R&DD were rationalising their stock in the mid-1980s the vehicle was donated to the DM&EE and became Test Car 4.

It was generally little used by the Testing Section, as it was too large (C3 loading gauge) and also the days of testing using numerous channels of data were fading. It also had limited staff facilities and a small fuel tank for its generator which limited its range of test work.

Test Car 4 RDB975984 was to have been scrapped in early 2003 but was rescued and now forms part of the New Measurement Train

Lab15 R&DD Lab 15 'Argus' pictured at Eastleigh on 21st July 1987 on what looks like a gauging trial

Neil Walkling

TC4 In Serco livery as Test Car 4 at Crewe Electric Depot on 3rd May 1997


SB1-C tests At Old Dalby in 1999 with a container gauging train for clearing OHLE for larger boxes


Inside Inside the vehicle showing the extensive instrumentation racks and fixed seating


In the NMT In the NMT formation at Carlisle on 3rd July 2007


NMT Back at Old Dalby on 30th July 2010



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