GWR 5101 Class

Specifications
Specifications
Configuration:;
• Whyte	2-6-2T
Gauge	4 ft 8+1⁄2 in (1,435 mm) standard gauge
Leading dia.	3 ft 2 in (0.965 m)
Driver dia.	5 ft 8 in (1.727 m)
Trailing dia.	3 ft 8 in (1.118 m)
Length	41 ft (12.50 m)
Loco weight	78.45 long tons (79.71 t; 87.86 short tons)
Fuel type	Coal
Fuel capacity	4.0 long tons (4.1 t; 4.5 short tons)
Water cap.	2,000 imp gal (9,100 L; 2,400 US gal)
Firebox:
• Grate area	20.35 sq ft (1.891 m2)
Boiler	GWR Number 2
Boiler pressure	200 psi (1,400 kPa)
Heating surface:
• Firebox	121.8 sq ft (11.32 m2)
• Tubes and flues	1,144.94 sq ft (106.368 m2)
Superheater:;
• Heating area	82.2 sq ft (7.64 m2)
Cylinders	Two
Cylinder size	18 in × 30 in (457 mm × 762 mm)

Type and origin
Type and origin
Power type	Steam
Designer	Charles Collett
Builder	GWR Swindon Works
Build date	1929–1949
Total produced	140

GWR 5101 Class
GWR 5101 Class
	Preserved 5101 Class locomotive 4160 at Minehead, West Somerset Railway, painted in British Railways lined-green livery.
Power type
Type and origin
Power type	Steam
Designer	Charles Collett
Builder	GWR Swindon Works
Build date	1929–1949
Total produced	140
Configuration:;
Specifications
Configuration:;
• Whyte	2-6-2T
Gauge	4 ft 8+1⁄2 in (1,435 mm) standard gauge
Leading dia.	3 ft 2 in (0.965 m)
Driver dia.	5 ft 8 in (1.727 m)
Trailing dia.	3 ft 8 in (1.118 m)
Length	41 ft (12.50 m)
Loco weight	78.45 long tons (79.71 t; 87.86 short tons)
Fuel type	Coal
Fuel capacity	4.0 long tons (4.1 t; 4.5 short tons)
Water cap.	2,000 imp gal (9,100 L; 2,400 US gal)
Firebox:
• Grate area	20.35 sq ft (1.891 m2)
Boiler	GWR Number 2
Boiler pressure	200 psi (1,400 kPa)
Heating surface:
• Firebox	121.8 sq ft (11.32 m2)
• Tubes and flues	1,144.94 sq ft (106.368 m2)
Superheater:;
• Heating area	82.2 sq ft (7.64 m2)
Cylinders	Two
Cylinder size	18 in × 30 in (457 mm × 762 mm)
Tractive effort
Performance figures
Tractive effort	24,300 lbf (108 kN)
Class
Career
Class	GWR 5101
Power class	GWR D ; BR 4MT
Axle load class	GWR Blue
Withdrawn	December 1965

The GWR 5101 Class or Large Prairie was a class of 2-6-2T steam locomotives of the Great Western Railway.

History

The 5101 Class were medium-sized tank engines used for suburban and local passenger services all over the Great Western Railway system. The class was an updated version, by Collett, of Churchward's 1903 3100/5100 Class.

The original 40 members of the 3100 class were renumbered 5100 and 5111 to 5149 in 1927. The first batches of 5101s filled in the numbers 5101 to 5110 and extended the class from 5150 to 5189. They were little changed from the Churchward locomotives as they then were, but had an increased axle loading of 17 long tons 12 cwt (39,400 lb or 17.9 t); the maximum permitted for the ‘Blue’ route availability. Bunkers were of the standard Collett design with greater coal capacity. The 5100 number series was exhausted in 1934, and further new locomotives were numbered from 4100.

Improvement

In 1938, the GWR began a modernisation programme to the earlier locomotives, rebuilding them to provide greater availability and more tractive effort. This would allow them to undertake their original mixed-traffic duties on a wider selection of routes, as well as banking. The 3100 class were to be rebuilt as the 3500 class, with Standard Class 4 boilers at 225psi replacing the original Standard Class 2 at 200psi, and using coupled wheels of 5 feet 3 inches diameter, which in combination took tractive effort up to 31,170 pounds. Only five engines were rebuilt pre the onset of World War 2. The last of the large prairie locomotives constructed were 4140 to 4179, built to the last GWR design by British Railways at Swindon.^[1]

As both freight and passenger traffic on branch lines declined post-WW2 with increasing volumes of private motor cars, and replacement on urban services by diesel-powered rail cars, the bulk of the class found itself allocated to various mainline support duties, mainly banking and piloting, often on the South Devon Banks on the Exeter to Plymouth Line, or around the Severn Tunnel on the South Wales Main Line.

Preservation

A number of the class - 4110, 4115, 4121, 4144, 4150, 4156 and 4160 - ended their operational lives allocated to the major locomotive shed (88E) at Severn Tunnel Junction, undertaking piloting and banking duties through both the Severn Tunnel and the associated goods yard.^[3] Assistance was needed by all heavy trains through the Severn Tunnel, which entailed: 3.5 miles (5.6 km) of 1-in-90 down to the middle of the tunnel; then a further 3.5 miles (5.6 km) at 1-in-100 up to Pilning; a short level then 3.5 miles (5.6 km) more at 1-in-100 to Patchway. However, the pilot locomotive usually came off at Pilning.

All were withdrawn by June 1965, and subsequently sold for scrap to Woodham Brothers. Woodham's had prioritised processing for scrap the easier to handle former coal wagons over the more complex steam locomotives, giving rise to the large number of retained steam locomotives at Barry Island into the late 1970s. However, following a period of theft from the yard and BR being unable to offer any quantity of redundant wagons, rather than lay off staff, in summer 1980 Dai Woodham authorized the scrapping of two steam locomotives, BR Standard Class 9F No. 92085, and 5101 class No.4156. By August, more former steel coal wagons had been delivered to the yard, making 4156 and 92085 the last locomotives to be broken up at Barry.^[4]

The rest of the former Severn Tunnel Junction locomotives now form the bulk of the ten class members that have subsequently been bought for preservation. Eight are in various states or preservation or operation, whilst two have acted as donor locomotive for other projects:

Number	Owner	Current Location	Status	Notes
5164	5164 Preservation Group	Barrow Hill Engine Shed	Boiler certificate expired 5 January 2014	Normally located at the Severn Valley Railway, currently on display at Barrow Hill MPD for at least 12 months.^{[citation needed]}
5193	West Somerset Railway plc	West Somerset Railway	Rebuilt as GWR 4300 Class, No.9351. Currently under overhaul	Originally built in 1934, withdrawn in 1962 and recovered from Woodham Brothers scrapyard in 1979. Rebuilt by the West Somerset Railway into a 2-6-0 resembling a small boilered version of the GWR 4300 Class: remove the water tanks; remove whole rear of the locomotive including the rear of the frames, trailing wheels and fuel bunker; add tender. Renumbered 9351.
5199	Llangollen Railway	Llangollen Railway	Operational	Overhaul completed 23 November 2014
4110	West Somerset Railway plc	West Somerset Railway	Unrestored	Sold in May 2015 by GWR Preservation Group Limited of Southall Railway Centre to WSR plc. Moved to Minehead 16 June 2015.
4115	Great Western Society	Didcot Railway Centre	Donor locomotive	Built October 1936, withdrawn from service in June 1965. One of the "Barry Ten", she was sold to the Great Western Society, Didcot in 2010, to act as a donor locomotive for the creation of two new locomotives:^[5] GWR 4700 Class 2-8-0 No. 4709, to which it will donate: front end extension frames and cylinder sub-assembly; six of the eight 5ft 8in driving wheels required; frame stays; footplate supports; brake hangers; vacuum brake cylinder and reservoir; weighshaft and bearings GWR 2221 Class County Tank 4-4-2T, to which it will donate its boiler.
4121		Tyseley Locomotive Works	Unrestored, partially stripped	Stored at Tyseley in a partially stripped down state
4141		Epping Ongar Railway	Operational	Returned to steam in 2012 after an overhaul
4144	Great Western Society	Didcot Railway Centre	Operational	Returned to steam in 2015 after an overhaul
4150	4150 fund	Severn Valley Railway	Restoration in progress
4160	4160 Ltd	Llangollen Railway	Under Overhaul	Overhauled in 2007, operated on the West Somerset Railway. Until recently West Somerset Railway Association had a 28% share, but in late Autumn 2015 two long standing directors of 4160 Ltd purchased the holding. Sent to the Llangollen Railway in January 2016 for overhaul