BR Standard Class 4 4-6-0

Preserved Standard Class 4 4-6-0 No. 75027 on the Bluebell Railway

Type and origin
Power type	Steam
Designer	R. A. Riddles
Builder	BR Swindon Works
Build date	May 1951 – May 1957
Total produced	80

Specifications
Configuration	4-6-0
UIC class	2′C h2
Gauge	4 ft 8 ¹⁄₂ in (1,435 mm)
Leading dia.	3 ft 0 in (0.914 m)
Driver dia.	5 ft 8 in (1.727 m)
Length	60 ft 0 in (18.29 m)
Width	8 ft 9 ¹⁄₂ in (2.68 m)
Height	13 ft 0 in (3.96 m)
Axle load	17.25 long tons (17.53 t; 19.32 short tons)
Adhesive weight	51.55 long tons (52.38 t; 57.74 short tons)
Loco weight	67.90 long tons (68.99 t; 76.05 short tons)
Tender weight	BR1B: 49.15 long tons (49.94 t); BR2/BR2A: 42.15 long tons (42.83 t)
Tender type	BR1B (15), BR2 (50), BR2A (15)
Fuel type	Coal
Fuel capacity	BR1B: 7.00 long tons (7.11 t; 7.84 short tons); BR2/BR2A: 6.00 long tons (6.10 t; 6.72 short tons)
Water cap	BR1B: 4,725 imp gal (21,480 l; 5,674 US gal); BR2/BR2A: 3,500 imp gal (16,000 l; 4,200 US gal)
Firebox: • Firegrate area	26.7 sq ft (2.48 m²)
Boiler	BR4
Boiler pressure	225 psi (1.55 MPa)
Heating surface: • Tubes and flues	1,301 sq ft (120.9 m²)
• Firebox	143 sq ft (13.3 m²)
Superheater:
• Heating area	258 sq ft (24.0 m²)
Cylinders	Two, outside
Cylinder size	18 in × 28 in (457 mm × 711 mm)

Performance figures
Tractive effort	25,515 lbf (113.5 kN)
Factor of adh	4.52

Career
Operators	British Railways
Power class	4MT
Numbers	75000–75079
Axle load class	BR1B: Route Availability 7 BR2/BR2A: Route Availability 4
Withdrawn	October 1964 – August 1968
Disposition	6 preserved, remainder scrapped

The British Railways Standard Class 4 4-6-0 is a class of steam locomotives, 80 of which were built during the 1950s. Six have been preserved.

Background

The class was introduced in 1951. They were designed for mixed traffic use on secondary routes where the otherwise ubiquitous BR standard class 5 and their predecessors, the Black Fives, would be too heavy. They were essentially a tender version of the standard 4 2-6-4T, with similar characteristics to the GWR Manor Class, though unlike the Manors they were built to the universal loading gauge. They used the same running gear as the tank engine (with the leading bogie from the Standard Class 5), and substantially the same firebox, smokebox and boiler, although the boiler barrel was increased in length by 9 inches (229 mm).

Design work was done at Brighton by R. A. Riddles, with help from Swindon, Derby and Doncaster. Construction was at the BR Swindon Works.

The engine weighed 67.90 long tons (68.99 t; 76.05 short tons), was 60 ft 0 in (18.29 m) long, with 5 ft 8 in (1.727 m) diameter driving wheels. It had two cylinders of 18 inches (457 mm) diameter and 28 inches (711 mm) stroke operated at maximum boiler pressure of 225 lbf/in² (1.55 MPa), to produce 25,515 lbf (113.5 kN) tractive effort. Its British Railways power classification was 4MT.

It normally used the standard BR2 or BR2A tender, which weighed 42.15 long tons (42.83 t; 47.21 short tons) and carried 3,500 imp gal (16,000 l; 4,200 US gal) of water and 6.00 long tons (6.10 t; 6.72 short tons) of coal. In this configuration its route availability was 4, almost universal over the British Railways network.

In service

75073 at Bath Green Park shed in the mid-1960s

The class was initially allocated to the London Midland Region (45) and the Western Region (20). The last 15 were allocated to the Southern Region. The Southern batch were built with BR1B tenders, which weighed 49.15 long tons (49.94 t; 55.05 short tons), and carried 4,725 imp gal (21,480 l; 5,674 US gal) of water and 7.00 long tons (7.11 t; 7.84 short tons) of coal. This reduced their route availability to 7, the same as the Standard Class 5.

Table of withdrawals
Year	Quantity in service at start of year	Quantity withdrawn	Locomotive numbers
1964	80	2	75001/67
1965	78	11	75000/03/05/07–08/22/25/28/38/72–73
1966	67	20	75011/14/23/31/36/44–45/49–51/53–54/56–57/63/65–66/69–70/79
1967	47	37	75002/04/06/10/12–13/15–18/24/26/29–30/33/35/37/39–40/42–43/46–47/52/55/58–61/64/68/71/74–78
1968	10	10	75009/19–21/27/32/34/41/48/62

Preservation

Number and name	Home	Status
75014 "Braveheart"	Dartmouth Steam Railway	Nearing completion of overhaul. Due back in 2016.
75027	Bluebell Railway	Awaiting overhaul, recently received some cosmetic attention.
75029 "The Green Knight"	North Yorkshire Moors Railway	Operational, boiler ticket expires in 2021. Passed for main line operation between Battersby and Whitby, for which it is TPWS fitted.
75069	Severn Valley Railway	Undergoing overhaul with major work required on the boiler.
75078	Keighley and Worth Valley Railway	Operational, boiler ticket expires in 2024.
75079	Mid-Hants Railway	Undergoing restoration.

All bar 75079 have worked in preservation at some point. Three of them (75014, 75029 and 75069) have worked on the main line. No. 75029 is passed to work on the main line between Battersby and Whitby.

Modelling

Bachmann and Hornby have both recently released models of the these engines in 00 gauge.

References

A Detailed History of BR Standard Steam Locomotives, - Vol 2 - The 4-6-0 and 2-6-0 Classes. RCTS ISBN 0-901115-93-2
Bradley, Rodger P. (1984). The Standard Steam Locomotives of British Railways. David & Charles. ISBN 0715383841.

External links

Wikimedia Commons has media related to BR Standard Class 4 4-6-0.

British Railways steam locomotives

Standard classes:	Class 7 Britannia Class 8 Duke of Gloucester Class 6 Clan 5MT 4-6-0 4MT 4-6-0 4MT 2-6-0 3MT 2-6-0 2MT 2-6-0 4MT 2-6-4T 3MT 2-6-2T 2MT 2-6-2T 9F

TOPS class:	Class 98

British Railways steam locomotives GWR locomotives LMS locomotives LNER locomotives Southern Railway locomotives

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