Test vehicles Iris 1 and 2

The R&D Division of BR utilised two diesel units which were known as Iris 1 (No: RDB975010) - converted from a single car Derby Lightweight unit, and Iris 2 (also known as Lab 19), a two car Metro Cammell Class 101 unit, (Nos:RDB977692 (ex-53222) and RDB977693 (ex-53338) converted by the R&DD from a power twin unit.

The author caught up with these stalwarts in their latter years when they were being operated by Railtest and took part in several test series with both units.

Iris 1 was originally built as a two-car Derby Lightweight DMU in 1954 and was later converted into two single cars. This contemporary article from the September 1956 issue of the London Midland Region magazine describes the intended use of the single car unit M79900 on the Buckingham branch. John Spencer Gilks also has a number of photographs of M79900  in his excellent trilogy of books 'Dawn of the Diesels'.

It was used by the R&DD for radio survey work and also general testing and was originally painted in the Division's red and blue livery and designated 'Test Coach Iris '.

In its later years the unit was re-painted into BR green and carried both its original running number as well as its Departmental one. Luckily it was never painted in Serco's red and grey livery.

In 1997 I was involved with Iris 1 when it was used to undertake a rush job related to 3rd rail shoegear clearance on the WCML. There was a new service to be introduced between Rugby and Gatwick service using dual voltage class 319 units. Although WCML had been gauge-cleared for Eurostars (which had retractable shoegear) somebody forgot that 319's didn't and there were doubts about the lines between Rugby and Bletchley. I recollect spending the some time pottering between these two places via the main line and via Northampton during a very hot July. Iris 1 was very compact having a diesel generator squeezed into the guard's area and a kitchen and a couple of seats in the opposite end. The main instrumentation area took up most of the vehicle. It rode like a pig at 75 mile/h but luckily we didn't go that fast very often!

Iris 1 is now retired and was very nicely restored at the Midland Railway Centre, Butterley Derbyshire to virtually original condition and was used occasionally in passenger service on the MRC.

In early 2008 it made a visit to the Churnet Valley Railway and then to its new home on the Ecclesbourne Valley Railway where it runs regular passenger diagrams most weekends. For more information see the railway's site at www.e-v-r.com.

Here is a selection of photos of Iris 1

Click on the picture for a bigger image - photos are the author's where not credited

High Wycombe Pictured at High Wycombe in its earlier red and blue R&DD livery, Test Coach Iris heads off towards Marylebone whilst a class 50-hauled Down express approaches behind 50004.

Colin Berry

Colour Test Coach Iris is pictured inside Stanton Tunnel whilst conducting a radio survey into 'Leaky feeder' cables in the mid-1970's

John Goss - Central Photographic Unit (British Rail)

An R&DD employee on board Iris monitors the signal strength in the tunnel

John Goss - Central Photographic Unit (British Rail)

Iris is about to enter the south end of Stanton Tunnel

John Goss - Central Photographic Unit (British Rail)

Test Coach Iris at an unknown open day c1979/80


Test Coach Iris in the red and blue of the R&DD at the RTC about 1982 - in the background is the SGT optical car and HSFV4


At Crewe Basford Hall open day in 1984 with Test Car one painted in GWR chocolate and cream for the 150th anniversary of the GWR

Phil Wimbush

Test Coach Iris at London Bridge on 4th April 1987

Steve Hampton

Test Coach Iris on Reading depot in 1991

Darren Ford

Iris 1 at Old Dalby test track Test Coach Iris is seen at Grimston on the Old Dalby test track during trials of a shoegear gauging device in May 1997. It was also used at the test track to trial the prototype TPWS system.
Bletchley depot In July of 1997 the unit was based at Bletchley depot whilst gauge-clearing the route from Bletchley to Northampton prior to the introduction of class 319 units on the Rugby to Gatwick services. Note it displays its original number on the side and departmental number on the end.
Unknown Another shot but this time at an unknown location - probably during radio survey work Iris 1 Guildford In the summer of 1999 Iris 1 stands at Littlehampton whilst the train crew nip off to buy some rock. This was during an extensive radio survey on Railtrack's Southern Zone
Just like new Iris 1 restored to its original condition pictured at the MRC, Butterley on 18th August 2005 Cheddleton Amongst other DMU's Iris is pictured at Cheddleton on the CVR on 2nd February 2008
Wirksworth A resident at the Ecclesbourne Valley Railway on 13th May 2010  

Iris 2 was converted in 1991 from a Met Cam class 101 power twin unit at the R&DD to a high standard as a test train known as "Lab 19 - Iris II" which it always had displayed on its destination blinds. It was completely re-furbished inside. One vehicle was equipped with a diesel generator set, kitchen and eating area and an instrumentation area with air conditioning . The other vehicle was not to the same high standard but had a small workshop and storage area and bunk beds for the use on night work when stabled. I remember once spending the night on Iris2 at Reading depot when the night job was cancelled and we had no hotel.

Work undertaken on Iris 2 when I was first involved included radio survey work in connection with the NRN which was regularly undertaken particularly on the GW and Southern Zones of RT. Later Iris 2 was chosen to undertake pioneering video surveying of the whole railway,  which included all lines from Penzance to Thurso. I remember one trip from Clapham Junction Yard to Penzance Long Rock depot - all the way down the old LSWR main line in the cab! Happy days.

We also undertook a signal sighting survey prior to the WCML upgrade on all lines between London and Glasgow including diversions. This was in connection with raising the speed to 125 mile/h.

Iris 2 was retired at the end of the 1990's but was back in action in 2004 conducting yet more radio surveys. However, it had by then been given the all-over yellow livery favoured by Network Rail. At least it looks better than the hideous Railtrack livery of lime green and dark blue.

In late 2007 Iris 2 was finally retired and was offered for sale. In March 2008 it moved to the West Somerset Railway at Dunster, where it was re-painted green and used by the Permanent Way Department.

On August 17th 2009 The West Somerset Railway unofficial site (wsr.org.uk) had the following information 

"IRIS II heads for Wales The two-car DMU IRIS II is about to leave for Wales. It has been stored unused at Dunster Yard for over a year. During that time the DMU - Network Rail Laboratory 19 IRIS II test train 901002 - was repainted by its owner from yellow to a more heritage style green livery. Recently towed to Minehead, the DMU will be moved to Bishops Lydeard in a few days, thence transported by road to Barry. WSR General Manager Paul Conibeare commented "The owner, John Buxton, is removing it to Barry to run services on the new railway, which John has just taken over. We wish John all the best with his new venture and I am sure IRIS II will be a popular and useful vehicle."

It now resides at the Barry Tourist Railway where it has been refurbished and turned into a comfortable passenger environment. Look here for some technical details of the two vehicles and a summary of its recent movements

 Here is a selection of photos of Iris 2. 

Click on the picture for a bigger image - photos are the author's where not credited

Salisbury Jcn Not long after conversion Iris 2 (Lab 19) is seen here passing Salisbury Tunnel Junction wearing the later R&D livery of grey and blue.

Geoff Gillham

Reading? Another shot in the grey livery at Reading

Steve Dyks

Stabled at Cambridge in the early 1990s

C Niven

Colnbrookdale By 1999 Iris 2 was in Serco's red and grey livery and is pictured at the end of the Colnbrookdale branch from West Drayton whilst carrying out a radio survey on GW Zone. This is next to the end of one of the runways at Heathrow.
Inside Iris 2 showing the control panel for the generator and the high standard of finish. Paddington Pictured at Paddington during the GW Zone radio and video survey in 1999 

Chris Ward

Bourne End Iris 2 at Bourne End .................. Marlow ...............and this time at Marlow 
Where is this? Another view of Iris 2 on its travels on the GW Zone in 1998 Didcot In the hideous Railtrack livery passing Didcot on 24th April 2003

Simon Bendall

RTC June 2004 And in its Network Rail incarnation in yellow with a new set number 901002 at RTC in June 2004 Up the yard Still going strong on 8th March 2005
Iris 2 is pictured  on the West Coast Main Line at South Kenton on 21st January 2006

Phil Wimbush

Reading depot Iris 2 at Reading Depot in November 2007

Andy Fearn

Reading depot Iris 2 heads off depot up the slope towards the station on 7th November 2007

Andy Fearn

Iris 2 retired Iris 2 at Dunster on the West Somerset Railway on 14th June 2008
Iris 2 in green Pictured at Dunster on 2nd October 2008, the unit had been repainted into a strange hue of green - a livery it never carried in R&DD use. It should have made the Pway gangs on the WSR a very nice comfortable messing unit. .

However it somehow never got used on WSR and was reported on 17th August 2009 to be on its way to the Barry Tourist Railway in South Wales


Together Iris 1 and Iris 2 pictured in the workshop at the RTC in the mid 1990's

Author's collection


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