BR standard class 4 4-6-0

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BR Standard Class 4 4-6-0
75027HK.JPG
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 classification 2′C h2
Gauge 4 ft 8 12 in (1,435 mm)
Leading wheel
diameter
3 ft 0 in (0.914 m)
Driver diameter 5 ft 8 in (1.727 m)
Length 60 ft 0 in (18.29 m)
Width 8 ft 9 12 in (2.68 m)
Height 13 ft 0 in (3.96 m)
Axle load 17.25 long tons (17.53 t)
Weight on drivers 51.55 long tons (52.38 t)
Locomotive weight 67.90 long tons (68.99 t)
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);
BR2/BR2A: 6.00 long tons (6.10 t)
Water capacity BR1B: 4,250 imp gal (19,300 l; 5,100 US gal);
BR2/BR2A: 3,500 imp gal (16,000 l; 4,200 US gal)
Boiler BR4
Boiler pressure 225 psi (1.55 MPa)
Firegrate area 26.7 sq ft (2.48 m2)
Heating surface:
– Tubes and flues
1,301 sq ft (120.9 m2)
– Firebox 143 sq ft (13.3 m2)
Superheater 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
adhesion
4.52
Career
Operator(s) British Railways
Power class 4MT
Number(s) 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Withdrawn October 1964 – August 1968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[edit]

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 (23 cm).

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), 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) and carried 3,500 imp gal (16,000 l; 4,200 US gal) of water and 6.00 long tons (6.10 t) of coal. In this configuration its route availability was 4, almost universal over the British Railways network.

In service[edit]

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), and carried 4,250 imp gal (19,300 l; 5,100 US gal) of water and 7.00 long tons (7.11 t) of coal. This reduced their route availability to 7, the same as the Standard Class 5.

Preservation[edit]

Number and name Home Status Image
75014 "Braveheart" Dartmouth Steam Railway Undergoing overhaul. Churston 75014 in workshops.jpg
75027 Bluebell Railway Awaiting overhaul, recently received some cosmetic attention. 75027 Bluebell railway.jpg
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. 75029 at Grosmont (1).jpg
75069 Severn Valley Railway Undergoing overhaul with major work required on the boiler. Standard class 4MT 75069 at Hastings, Ashford 150.jpg
75078 Keighley and Worth Valley Railway Undergoing overhaul. Keighley and Worth Valley Railway near Haworth - geograph.org.uk - 624800.jpg
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[edit]

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

References[edit]

  • 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 Publishers plc. 

External links[edit]