BR Standard Class 5
No 73142 ready to depart with the 10.50 Express from London St Pancras to Leicester in 1957. Note the Caprotti valve gear.
Power type	Steam
Designer	R. A. Riddles
Builder	BR Derby Works (130) BR Doncaster Works (42)
Build date	April 1951 - June 1957
Total produced	172
Configuration	4-6-0
UIC classification	2'Ch
Gauge	4 ft 8 1⁄2 in (1,435 mm)
Leading wheel diameter	3 ft 0 in (0.914 m)
Driver diameter	6 ft 2 in (1.880 m)
Length	62 ft 7 in (19.08 m)
Width	8 ft 9 in (2.67 m)
Height	13 ft 0 in (3.96 m)
Axle load	19.70 long tons (20.02 t)
Weight on drivers	58.05 long tons (58.98 t)
Locomotive weight	76.00 long tons (77.22 t)
Tender weight	BR1/BR1H: 49.15 long tons (49.94 t); BR1B: 51.25 long tons (52.07 t); BR1C: 53.25 long tons (54.10 t); BR1F: 55.25 long tons (56.14 t); BR1G: 52.50 long tons (53.34 t);
Tender type	BR1 (50), BR1B (62), BR1C (35), BR1F (10), BR1G (3), BH1H (12)
Fuel capacity	BR1C: 9.00 long tons (9.14 t); All others: 7.00 long tons (7.11 t)
Water capacity	BR1/BR1H: 4,250 imp gal (19,300 l; 5,100 US gal); BR1B/BR1C: 4,725 imp gal (21,480 l; 5,674 US gal); BR1F: 5,625 imp gal (25,570 l; 6,755 US gal); BR1G: 5,000 imp gal (23,000 l; 6,000 US gal)
Boiler	BR3
Boiler pressure	225 psi (1.55 MPa)
Firegrate area	28.7 sq ft (2.67 m2)
Heating surface: Tubes and flues	1,479 sq ft (137.4 m2)
Heating surface: Firebox	171 sq ft (15.9 m2)
Superheater area	358 sq ft (33.3 m2)
Cylinders	Two, outside
Cylinder size	19 × 28 in (483 × 711 mm)
Valve gear	Walschaerts (73000–73124, 73155–73171) Caprotti (73125–73154)
Tractive effort	26,120 lbf (116.2 kN)
Factor of adhesion	4.97
Career	British Railways
Power class	5MT
Number	73000–73171
Axle load class	Route availability 7 BR (WR): red
Withdrawn	February 1964 – June 1968
Disposition	Five preserved, remainder scrapped

The British Railways Standard Class 5MT 4-6-0 was one of the 12 standard classes of steam locomotive built by British Railways in the 1950s. It was essentially a development of the LMS Stanier Class 5 4-6-0 ("Black Five"). 172 were built between 1951 and 1957.

  Background

William Stanier's Black Five had been the most successful mixed-traffic type in Great Britain. Construction of the Black Fives had started in 1934 and continued past nationalisation to 1951. A new set of 'standard' locomotives was to be built by British Railways, based on LMS designs and incorporating modern ideas.

In particular, the Standard design incorporated features designed to make disposal easier: a self-cleaning smokebox and a rocking grate removed the necessity for crews to undertake dirty and strenuous duties at the end of a long shift.^[1]

  Design and construction

The design work was done at the ex-LNER Doncaster Works but the bulk of the construction was done at Derby Works. The locomotive featured a Type 3B boiler almost identical to that of the Black Fives. The most obvious visible changes were a higher running plate, slightly enlarged driving wheels (from 6 ft 0 in (1.829 m) to 6 ft 2 in (1.880 m)) and a standard cab.

The first of the class, 73000, was outshopped from Derby in April 1951 and 30 were in service by January 1952. There was then a gap in construction before Derby resumed building its remaining 100 engines. 42 were built at Doncaster, starting in August 1955 and finishing in May 1957, with Derby's last engine following a month later.

Thirty engines, numbers 73125 to 73154, were built with Caprotti valve gear and poppet valves. One of these engines (73129) survives today at Butterley. It and 71000 Duke of Gloucester are the only engines with Caprotti gear left in Britain.

  In service

In 1959 20 of the Southern Region locomotives were named, the names being transferred from SR King Arthur class locos that were then being withdrawn. These were:

• 73080 Merlin
• 73081 Excalibur
• 73082 Camelot
• 73083 Pendragon
• 73084 Tintagel
• 73085 Melisande
• 73086 The Green Knight
• 73087 Linette
• 73088 Joyous Gard
• 73089 Maid of Astolat
• 73110 The Red Knight
• 73111 King Uther
• 73112 Morgan Le Fay
• 73113 Lyonnesse
• 73114 Etarre
• 73115 King Pellinore
• 73116 Iseult
• 73117 Vivien
• 73118 King Leodegrance
• 73119 Elaine

  73002 passing through Water Orton, 1964.

73020 is known to have been used on Southern Region, photographed departing Southampton Terminus on 18 September 1965.^[2]

73022 has also been photographed in service on the Southern Region, pulling a Boat Train across Canute Road in Southampton on 29 September 1966.^[2]

73114 Etarre has been photographed in service on 20 March 1966, pulling a Boat Train through Fareham while diverted due to electrification work on the Southern Region mainline from Southampton to London Waterloo.^[2]

  Preservation

  73096 arriving at Alton station

  Preserved 73096 on the mainline at Virginia Water.

Five have survived:

  Notes

  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 Publishers plc. 

  External links

Wikimedia Commons has media related to: BR Standard Class 5MT

• Southern E-group photo gallery
• Website for 73129