| Powertype: | Steam |
| GWR 6400 and 7400 Classes | |
| Designer: | Charles Collett |
| Builder: | GWR/BR Swindon Works |
| Whytetype: | 0-6-0PT |
| Driverdiameter: | 4feet |
| Length: | 31feet |
| Width: | 8feet |
| Height: | 12feet |
| Fueltype: | Coal |
| Fuelcap: | (2LT) |
| Watercap: | 1100impgal |
| Firearea: | 16.76square feet |
| Boiler: | GWR Standard No. 21 |
| Cylindercount: | two inside |
| Cylindersize: | NaNx |
| Valvegear: | Stephenson |
| Valvetype: | piston valves |
| Operator: | Great Western RailwayBritish Railways |
| Operatorclass: | GWR 6400 and 7400 |
| Locale: | Western Region |
| Withdrawndate: | 1958–1965 |
| Disposition: | Three 6400s preserved, remainder scrapped. All 7400 locomotives scrapped. |
The Great Western Railway (GWR) 6400 Class is a class of 0-6-0 pannier tank steam locomotive introduced by Charles Collett in 1932. All 40 examples were 'auto-fitted' – equipped with the remote-control equipment needed for working autotrains.
The 1936 GWR 7400 Class was a similar class, without the autotrain apparatus, but with a higher boiler pressure of 180 psi, providing a small but useful increase in power. An initial build of 30 in 1936-1937 was added to by British Railways in two batches each of ten locos in 1948 and 1950. These were destined for a short life, the briefest being only nine years. A minor visual difference between the 5400 and earlier 6400, and the later series of 6400, with the 7400 classes was at the join between cab and bunker. The 5400 and early 6400 had an arc whereas the later 6400 and the 7400 class was straight. The early locos also had a lip at the leading edge of the cab roof, whereas the later locos had a plain corner edge.
Both classes were closely related to the 1930 GWR 5400 Class, which was in turn an evolution of both the Armstrong 1874 GWR 850 Class and the Dean 1891 GWR 2021 Class. Thus the basic design was almost sixty years old when new, the 4feet driving wheels being the main distinguishing factor, apart from the more modern profile. There were also superficial similarities with the GWR 645 Class as extant in the 1930s, that also had 4feet wheels and 240NaN0 stroke cylinders (and by then pannier tanks and full cabs).
| 1932 | 10 | 277 | 6400–6409 | align=left | ||
| 1934–35 | 15 | 294 | 6410–6424 | align=left | ||
| 1935 | 5 | 300 | 6425–6429 | align=left | ||
| 1937 | 10 | 305 | 6430–6439 | align=left | ||
| 1936–37 | 30 | 307 | 7400–7429 | align=left | ||
| 1948 | 10 | 371 | 7430–7439 | align=left | ||
| 1950 | 10 | 380 | 7440–7449 | align-left |
The smaller wheels of the 6400's permitted operation in hillier locations than the 5400 Class and allocations were initially to the South Wales valleys.
Engines of class 6400 worked on many of the ex-GWR branch lines in Devon and around Plymouth until the early 1960s, when the lines closed or diesel multiple units took over services. No. 6430 was a regular engine on the old Tavistock South branch line and would often run with two autocoaches. No. 6412 was allocated at Gloucester Horton Rd loco shed (85B) and operated one of the last 'Chalford Railcar' autotrain services between Gloucester and Chalford on 31 October 1964.[2]
Being allocated to Plymouth Laira the type was trialled on the former Lostwithiel and Fowey Railway, although a 1400 Class 0-4-2 engine was normally used.[3]
The below list shows when all of the original 6400's and later 7400's were withdrawn from service. The members of the GWR 6400 Class and the GWR 7400 Class were No. 6419 and No. 7439 respectively.[4] [5]
| 1958 | 90 | 3 | 3 | align=left | 6407/23/27 | |
| 1959 | 87 | 16 | 19 | align=left | 6402/04–05/09/14/17/20/28/32, 7401/11/15–16/20/38/47 | |
| 1960 | 71 | 5 | 24 | align=left | 6401/06/39, 7400/19 | |
| 1961 | 66 | 11 | 35 | align=left | 6411/13/15/25–26, 7409–10/17/21/29/33 | |
| 1962 | 55 | 15 | 50 | align=left | 6408/10/18/22/29/36/38, 7402/06/08/22/25/28/34/40 | |
| 1963 | 40 | 15 | 65 | align=left | 6403/16/21/31/33/37, 7405/07/12/26/30/41–42/48–49 | |
| 1964 | 25 | 23 | 88 | align=left | 6400/12/19/24/30/34–35, 7403–04/13–14/18/23–24/27/31–32/35–36/43–46 | |
| 1965 | 2 | 2 | 90 | align=left | 7437/39 |
Three of the 6400 Class have survived to preservation:
| Number | Built | Withdrawn | Service Life | Location | Owners | Livery | Condition | Photograph | Notes | |
|---|---|---|---|---|---|---|---|---|---|---|
| 6412 | Nov 1934 | Nov 1964 | 30 Years | South Devon Railway | South Devon Railway | BR Lined Green, Late Crest | Operational, Boiler Ticket Expires: 2024 | Starred in the TV series The Flockton Flyer[6] | ||
| 6430 | Mar 1937 | Oct 1964 | 27 Years, 7 months | South Devon Railway | Hugh Skipton | BR Lined Green, Early Emblem | Operational, Boiler Ticket Expires: 2025 | One of the few engines to escape Cashmore's scrapyard thanks to a last minute rescue by the Dart Valley Railway. Originally purchased as a source of spares for No. 6412 and No. 6435, the locomotive was eventually restored to working order in 2003.[7] [8] [9] | ||
| 6435 | Apr 1937 | Oct 1964 | 27 Years, 5 months | West Somerset Railway | Jon Jones-Pratt | BR Lined Green, Late Crest | Stored, Boiler Ticket Expired: 2022 | Briefly named Ajax during the early and mid-2000s.[10] [11] [12] [13] Changed ownership from Bodmin and Wenford Railway in January 2024 with plans for a return to service.[14] Will later be based at West Somerset Railway. Last ran in 2022 following expiry of its boiler ticket.[15] |