The London, Midland and Scottish Railway and British Railways Class 4 2-6-4T was a family of classes of steam locomotives. A grand total of 800 engines were built to five separate designs by four different mechanical engineers, over a period of 29 years. Each new design was a development of the previous one. The LMS gave the whole family the power classification 4P, BR 4MT. It is therefore worth considering them as a group as follows:

LMS NosBR NosDesignDesignerBuiltBuilt by LMSBuilt by BRTotal built
2300–242442300–42424FowlerHenry Fowler1927–19341250125
2500–253642500–42536Stanier, 3 cylinderWilliam Stanier193437037
2425–2494, 2537–267242425–42494, 42537–42672Stanier, 2 cylinderWilliam Stanier1935–19432060206
2187–2299, 2673–269942050–42299, 42673–42699FairburnCharles Fairburn1945–1951130147277
—80000–80154BR StandardRobert Riddles1951–19560155155
Total1927–1956498302800

Withdrawal

All engines were withdrawn from stock between 1959 and 1967, summarised as follows:

Locomotives withdrawn by year
YearFowlerStanier,
3-cylinder		Stanier,
2-cylinder		FairburnBR
Standard		Total
1959500005
196011120014
1961227173049
1962372943431153
19631602930075
1964200515731159
1965120385444148
196620114854115
19670015422582
Total12537206277155800
Locomotives in service at year end
YearFowlerStanier,
3-cylinder		Stanier,
2-cylinder		FairburnBR
Standard		Total
195812537206277155800
195912037206277155795
196010936204277155781
19618729187274155732
1962500144231154579
1963340115201154504
196414064144123345
196520269079197
19660015422582
1967000000

Technical comparison

For technical purposes, it is worth splitting the Fairburn tanks into two subclasses; early (42050–42146) and late (42147–42699) as their weights differ slightly.

Attribute Fowler Stanier, 3 cylinder Stanier, 2 cylinder Fairburn (early)[lower-alpha 1] Fairburn (late)[lower-alpha 2] BR Standard
Leading wheel diameter 3 ft 3+1⁄2 in (1.003 m)3 ft 0 in (0.914 m)
Driving wheel diameter 5 ft 9 in (1.753 m)5 ft 8 in (1.727 m)
Trailing wheel diameter 3 ft 3+1⁄2 in (1.003 m)3 ft 0 in (0.914 m)
Wheelbase 38 ft 6 in (11.73 m)37 ft 1 in (11.30 m)36 ft 10 in (11.23 m)
Length 47 ft 2+3⁄4 in (14.40 m)45 ft 9+3⁄4 in (13.96 m)44 ft 9+7⁄8 in (13.66 m)
Weight 86.25 long tons (87.63 t)92.25 long tons (93.73 t)87.75 long tons (89.16 t)85.25 long tons (86.62 t)84.70 long tons (86.06 t)86.50 long tons (87.89 t)
Axleload 17.95 long tons (18.24 t)
Coal capacity 3.50 long tons (3.56 t)
Water capacity 2,000 imp gal (9,100 L)1,875 imp gal (8,500 L)2,000 imp gal (9,100 L)
Boiler G8AS4CABR5
Boiler pressure 200 psi (1.38 MPa)200 psi (1.38 MPa)225 psi (1.55 MPa)
Firegrate area 25 sq ft (2.3 m2)25 sq ft (2.3 m2)26.7 sq ft (2.48 m2)
Heating surface: Tubes 1,082 sq ft (100.5 m2)1,011 sq ft (93.9 m2)1,223 sq ft (113.6 m2)
Heating surface: Firebox 138 sq ft (12.8 m2)137 sq ft (12.7 m2)143 sq ft (13.3 m2)
Superheater area 266 sq ft / 246 sq ft160 sq ft/154 sq ft240 sq ft (22 m2)
Cylinders 2 outside3 (1 inside, 2 outside)2 outside2 outside2 outside2 outside
Cylinder size 19 in × 26 in (483 mm × 660 mm)16 in × 26 in (406 mm × 660 mm)19.625 in × 26 in (498 mm × 660 mm)18 in × 28 in (457 mm × 711 mm)
Tractive effort 23,125 lbf (102.87 kN)24,598 lbf (109.42 kN)24,671 lbf (109.74 kN)25,515 lbf (113.50 kN)
  1. ↑ Derby Lots 177, 185, 186, and 196: locomotives 42147–42699, built 1945–1949
  2. ↑ Derby Lots 202, 210, and all Brighton-built locomotives: numbers 42050–42146, built 1948–1951

References

    • Bradley, Roger P. (1984). The Standard Steam Locomotives of British Railways. David & Charles.
    • Rowledge, J.W.P. (1975). Engines of the LMS built 1923–51. Oxford: Oxford Publishing Company. pp. 5–7, 42–44, 51–52. ISBN 0-902888-59-5.
    This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.