GNR Class O1

4 ft 8+1⁄2 in (1,435 mm)Leading dia.3 ft 2 in (965 mm)Coupled dia.4 ft 8 in (1,422 mm)Length60 ft 11.5 in (18.580 m)Loco weight76.2–78.65 long tons (77.42–79.91 t)Fuel typeCoalFirebox:​ • Grate area27 sq ft (2.5 m²)Boiler:
​ • Diameter5 ft 6 in (1,680 mm)Boiler pressure180 lbf/in² (1.24 MPa)Heating surface:​ • Firebox162 sq ft (15.1 m²) • Total surface2,084 sq ft (193.6 m²)Superheater:
​ • Type24 • Heating area570 sq ft (53 m²)CylindersTwo, outsideCylinder size21 in × 28 in (533 mm × 711 mm)Valve gearWalschaertsValve type10-inch (254 mm) piston valves

Performance figures
Tractive effort	33,735 lbf (150.06 kN)

Career
Operators	Great Northern Railway (Great Britain) London and North Eastern Railway British Railways
Power class	8F
Nicknames	Tangos
Axle load class	Route availability 6
Withdrawn	1947–1952
Disposition	All scrapped

The Great Northern Railway (GNR) Class O1 was a class of two-cylinder 2-8-0 steam locomotive designed by Nigel Gresley for heavy freight work and built by the GNR between 1913 and 1919.

History

Gresley designed the O1 2-8-0 for the heavy coal trains on the mainline from Grantham to London, ordering five examples 1913, which were completed at Doncaster in 1914. A further fifteen were ordered in January 1916, but due to the First World War delays were incurred and construction was transferred to the North British Locomotive Company, who delivered the first ten in April 1918, followed by a further five in October and November 1919.

Table of orders and numbers

Year	Order	Manufacturer	Serial number	Quantity	GNR Nos.	LNER Nos.	LNER 1944 Nos.	Notes
1913–14	EO 274	Doncaster Works	1411–1413, 1415, 1418	5	456–460	3456–3460	3475–3479
1919		North British Locomotive Co. (Hyde Park Works)	22060–22069	10	462–471	3462–3471	3480–3489
1919		North British Locomotive Co. (Atlas Works)	22099–22103	5	472–476	3472–3476	3490–3494

The class was re-designated O3 by the London and North Eastern Railway in 1944.

British Railways

Seventeen examples survived into British Railways ownership in 1948, but all had been withdrawn by 1952.

Table of withdrawals

Year	Quantity in service at start of year	Quantity withdrawn	Locomotive numbers	Notes
1947	20	3	3487, 3490, 3492
1948	17	2	3489/94
1949	15	0	–
1950	15	1	63491
1951	14	10	63475/77–81/83/85–86/93
1952	4	4	63476/82/84/88

References

• Boddy, M. G.; Brown, W. A.; Neve, E.; Yeadon, W. B. (November 1983). Fry, E. V. (ed.). Locomotives of the L.N.E.R., Part 6B: Tender Engines—Classes O1 to P2. Kenilworth: RCTS. ISBN 0-901115-54-1.

External links

• LNER encyclopedia