GWR Large Prairie 4150

GWR Large Prairie 4150
4150 20120721.jpg
4150 in course of restoration at Bewdley (Jul 2012)
Built By GWR Swindon Works
Configuration 2-6-2T
Power class GWR: D, BR: 4MT
Axle load class GWR: Blue
Status Under restoration
Loco Number 4150
Built 1947
Designed By Charles Collett
Type GWR 5101
1974 Purchased by The 4150 Fund
1978 Arrived on SVR
Length 41ft
Weight 78t 15cwt
Tractive effort 24,300 lb
Pressure 200 lb/sq in

Steam Locomotives

4150 is a GWR 5101 class 2-6-2T locomotive, commonly referred to as a 'Large Prairie'. It is the only SVR-based locomotive not to have steamed in preservation.

Large prairie tanks were a common sight on the GWR, with more than 300 built between 1903 and 1949 to the same basic design. The locomotives were designed to haul semi-fast and suburban passenger services to tight schedules, and were also used on medium distance freight services. A number of the class were allocated to Kidderminster and Shrewsbury sheds and were regularly used on the Severn Valley Railway in its declining years. Classmate 4175 was involved in the fatal accident at Northwood Lane level crossing in August 1964.

The 5101 Class was an updated version by CB Collett of Churchward's 1903 3100/5100 Class. Fellow class member GWR Large Prairie 5164 is an early 1930 example, while 4150 is a later post-War example. The 41xx number arose from the GWR practice, where more than 100 locomotives of one class were built, of maintaining the second number in the series and re-using older sequences of numbers where necessary. The prevalence of the Large Prairie also resulted in examples numbered 61xx, 31xx and 81xx.[1]


4150 in service

4150 was built at Swindon and entered service in June 1947. The first allocation was to nearby Stourbridge Junction shed (84F) where the locomotive would have worked local services towards Birmingham.

In November 1948 it was involved in an accident at Lapworth station. While running round its train bunker first, it was struck by another train which had overrun a signal at danger in thick fog.[2] 4150 returned to traffic 45 days later, after repair at Swindon. The front buffer plank of 4150 is stamped "9006" and, as Dukedog 9006 was withdrawn for scrap shortly before this incident, it seems likely that parts of the older locomotive were used in the repair of 4150.[3]

1953 to 1962 was spent in the West Country, mainly at Newton Abbot. The final allocation was to Severn Tunnel Junction where 4150, by then in run down condition, was used to bank heavy trains through the tunnel. The locomotive was withdrawn from service by BR in June 1965 after 18 years in service and sent to Barry Scrapyard.


4150 in preservation

4150 was purchased at a cost of £2,750 from Barry in 1973 by The 4150 Fund. No 4150 left Barry in 1974 in company with No.7812 Erlestoke Manor, and was towed by a Class 25 diesel to Parkend on the Dean Forest Railway.

Restoration at Parkend proved impossible, and in 1977 the Fund’s shareholders voted to move 4150 to the SVR, with the locomotive arriving at Bewdley on 19 January 1978. Restoration commenced following arrival in Bewdley Yard, but by the mid-80s fund raising and restoration progress had slowed considerably. In 2007 the Fund formed a new committee, and with renewed enthusiasm began a concerted effort to complete the restoration which had by then been in progress for more than 30 years. By 2014 a new bunker had been completed except for riveting and welding, and construction of new tanks was in progress.

By 2016 riveting of the side tanks and bunker was complete, leaving the baffles and other hidden parts to be welded in place after the major assemblies had been lifted on to the frames, to minimise the risk of distortion. At the time it was intended that the locomotive would be moved to Bridgnorth Loco Works for continuation of the overhaul in early 2017.[4][5] In March 2017 the boiler was removed and the newly fabricated tanks and bunker, plus the cab roof, were lifted onto the frames. Although the boiler was moved to Bridgnorth in June 2018, in the event it was decided that the rest of the locomotive would remained at Bewdley while work on the bunker, cab fittings, cab floor, and valve and cylinder cladding was completed.[6]

On 30 March 2021, 4150 and the Fund's stores van Fruit D 92080 were shunted out of Bewdley yard in preparation for a move to Bridgnorth,[7] more than 43 years after the locomotive arrived there. The chassis moved to Bridgnorth Loco Works on 30 April 2021. After several months in the yard, it was moved into the works itself and onto the jacks in August 2021[8].

The boiler

The locomotive’s present boiler is number 5895, a Class B/'Standard 2' boiler built at Swindon in September 1939. It was first installed on another 5101 class locomotive, number 4135, in November 1939 and subsequently at the higher pressure of 225 psi on 6100 class locos 6154 (May 1946), 6122 (August 1949) and 6168 (April 1946) before being fitted to 4150 in October 1963. 4150 had previously used boilers number 5855 on entry to service followed by 5646 (1950), 2278 (1953) and 3378 (1956).[9][10]

A full report in 2008 from the SVR's boiler foreman and a further inspection in 2018 showed the boiler to be in good condition, having been fitted with a new inner firebox at its last overhaul. It was expected to require the standard repairs: new flues, tubes, steel stays replaced, crown stays replaced, foundation ring removed to check for grooving and replaced, welding repairs to front tube plate and possible boiler barrel patch.

A record net total of almost £16,000 from the autumn 2007 Severn Valley Railway Association raffle proceeds were allocated to 4150 in 2008, which was ring-fenced for spending on the boiler.[11]A further raffle in 2018 raised in excess of £24,500 before expenses.[12][13]

By November 2016 the Fund had received confirmation that 4150 had a slot in the Bridgnorth Boiler Shop in the last quarter of 2017.[14] The Fund intended it to go to Bridgnorth in November 2017 for overhaul and in March 2017 it was lifted onto wagon 40554 for preparation work to begin.[15] Workload at in the boilershop meant that instead it was decided that boilershop staff would provide assistance to the owning group to accelerate the boiler overhaul at Bewdley.[16]

By January 2018 the boiler and firebox cladding had been completed and then dismantled. The boiler had passed an ultrasonic test on the thickness of the plates and passed a non-destructive test for cracks. Work had commenced on drilling out firebox steel stays and grinding off rivet heads holding the foundation ring before the boiler headed north.[17][18]

The boiler was moved from Bewdley to Bridgnorth on 18 June 2018 for work to be carried out in the boiler shop. On 29 December 2022 it was temporarily lifted into the locomotive's frames to enable all the large copper pipes to be made up and fittings test-fitted. It will need to be removed again at a later date to carry out hydraulic and steam testing[19].


See also


  1. Great Western Archive
  2. Newspaper cuttings on
  3. The 4150 Fund Newsletter, 2016
  4. SVR Live - 4150 - Prairie Tank, Ex GWR
  5. The 4150 Fund - September 2016 Restoration Update
  6. Shareholder update email, 28 July 2018
  7. 4150 Fund March 2021 Update
  8. 4150 Fund August update
  9. Copy of GWR Engine History card and Boiler History card obtained by the 4150 Fund
  10. 4150 Fund 2016 newsletter (retrieved 23 February 2019)
  11. 4150 Fund website (Retrieved 20 January 2018)
  12. SVR News 202
  13. 4150 Fund 2019 newsletter (retrieved 23 February 2019)
  14. 4150 Fund Newsletter 2017, January 2017
  15. Peep Behind The Scenes leaflet July 2017
  16. SVR News 200, Winter 2017
  17. Howard A, 4150 Fund Facebook, 20 January 2018
  18. The 4150 Fund - Restoration update January 2018
  19. 4150 Fund shareholder update, January 2023
  • SVR News
  • Severn Valley Railway Stock Book, seventh edition
  • 4150 Fund web site