| Powertype: | Steam |
| LNER Class O4 | |
| Designer: | John G. Robinson |
| Builddate: | 1911–1918 |
| Totalproduction: | 421 |
| Whytetype: | 2-8-0 |
| Uicclass: | 1′D h2 |
| Leadingdiameter: | 3feet |
| Driverdiameter: | 4feet |
| Tenderdiameter: | 4feet |
| Length: | 61feet |
| Wheelbase: | 51feet |
| Engine Total: | 25feet |
| Tender Total: | 13feet |
| Locoweight: | 72.5- |
| Fueltype: | Coal |
| Watercap: | 4000impgal |
| Fireboxtype: | Belpaire (some engines were fitted with round top fireboxes when the GCR was grouped into the LNER) |
| Lengthinside: | 15feet |
| Boilerpressure: | 1802NaN2 |
| Firearea: | 26.24square feet |
| Tubearea: | 1348square feet |
| Fireboxarea: | 153square feet |
| Superheatertype: | Robinson |
| Superheaterarea: | 225square feet |
| Totalsurface: | 1756square feet |
| Tractiveeffort: | 31325lbf |
| Cylindercount: | Two, outside |
| Cylindersize: | 21x |
| Valvegear: | Stephenson |
| Valvetype: | Piston valves |
| Powerclass: | BR: 7F |
| Fleetnumbers: | LNER (from 1946): 3500–3920 BR: 63570–63920 |
| Axleloadclass: | LNER/BR: Route Availability 6 |
| Withdrawndate: | December 1958 - April 1966 |
| Disposition: | One preserved, remainder scrapped |
The London and North Eastern Railway (LNER) Class O4 initially consisted of the 131 ex-Great Central Railway (GCR) Class 8K 2-8-0 steam locomotives acquired on grouping in 1923. The engines were designed by John G. Robinson and built at the GCR's Gorton Locomotive Works, Manchester.
The O4s were added to when the LNER purchased 273 ex-Railway Operating Division ROD 2-8-0s to the same design between 1923 and 1927. Meanwhile, the 19 GCR Class 8M (LNER Class O5) were rebuilt as O4 standard during the 1920s and 1930s. 92 O4 locomotives were requisitioned by the War Department during World War II and shipped during late 1941 for operation in the Middle East.
The O4 class were used to haul heavy freight trains throughout the LNER system. 329 engines remained in operation at 1 January 1948.[1]
The LNER rebuilt many, allotting them into eight subclasses.Sub-class details:[2]
In 1944, 58 O4s were rebuilt with 100A boiler, Walschaerts valve gear and new cylinders at Gorton Works, then classified O1.
The surviving 329 Class O4 locomotives passed to British Railways (BR) on 1 January 1948. They were then widely operated on freight trains throughout the Eastern and North Eastern regions of BR. The locomotives were given BR numbers in the range 63570-63920 but this range included 58 locomotives which had been rebuilt as Class O1. Withdrawal of O4 engines by BR commenced in 1959 and the last was taken out of service in the Doncaster area in April 1966.
An O4/1, GCR No. 102, BR No. 63601, is part of the extensive National Collection. Since 1996, this locomotive has been kept at the preserved Great Central Railway at Loughborough, Leicestershire. The locomotive was overhauled in the late 1990s and returned to working use in January 2000. A further three Robinson 2-8-0s were exported and survive in preservation in New South Wales, Australia.[3]