LNER Class A4

LNER Class A4
60009 Union of South Africa in 1951
Type and origin Power type Steam Designer Nigel Gresley Builder LNER Doncaster Works Build date 1935–1938 Total produced 35
Specifications Configuration: ​  • Whyte 4-6-2  • UIC 2′C1′ h3 Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Leading dia. 3 ft 2 in (0.965 m) Driver dia. 6 ft 8 in (2.032 m) Trailing dia. 3 ft 8 in (1.118 m) Length 71 ft 3⁄8 in (21.650 m) Width 9 ft 0 in (2.743 m) Height 13 ft 1 in (3.988 m) Loco weight 102 long tons 19 cwt (230,600 lb or 104.6 t) Total weight 167 long tons 2 cwt (374,300 lb or 169.8 t) Fuel type Coal Fuel capacity 8 long tons 0 cwt (17,900 lb or 8.1 t) Water cap. 5,000 imp gal (23,000 L; 6,000 US gal) Boiler pressure 250 psi (1.72 MPa) Cylinders Three Cylinder size 18.5 in × 26 in (470 mm × 660 mm) Valve gear Outside: Walschaerts Inside: Gresley conjugated Loco brake Vacuum Train brakes Vacuum 60007, 60009 & 60019 have been fitted with air brakes[1]
Performance figures Maximum speed 90 mph (140 km/h) in regular service (126.4 mph (203.4 km/h) maximum recorded) Tractive effort 35,455 lbf (157.71 kN)
Career Operators London and North Eastern Railway, British Railways Class A4 Power class BR: 8P6F Number in class 35 Numbers LNER (until 1946/47): 2509–2512, 4462–4469, 4482–4500, 4900–4903; LNER (from 1946/47): 1–34 (not in order); BR: 60001–60034 Nicknames "Streak" Locale East Coast Main Line Withdrawn 1942 (1), 1962–1966 Preserved 4488, 4489, 4464, 4496, 4498, 4468 Disposition Six preserved, remainder scrapped.

The LNER Class A4 is a class of streamlined 4-6-2 steam locomotive designed by Nigel Gresley for the London and North Eastern Railway in 1935. Their streamlined design gave them high-speed capability as well as making them instantly recognisable, and one of the class, 4468 Mallard, holds the record as the world's fastest steam locomotive. Thirty-five of the class were built to haul express passenger trains on the East Coast Main Line route from London Kings Cross via York to Newcastle, and later via Newcastle to Edinburgh, Scotland. They remained in service on the East Coast Main Line until the early 1960s when they were replaced by Deltic diesel locomotives; they themselves proving to be worthy successors to the A4s.^[2] Several A4s saw out their remaining days until 1966 in Scotland, particularly on the Aberdeen – Glasgow express trains, for which they were used to improve the timing from 3.5 to 3 hours.