GNR Gresley A1

From Railways

[edit] Class Summary

Designer	GNR Class	LNER Class	BR Class	First Built	Last Built	First Rebuilt	Last Rebuilt	Total Built	Preserved?
Nigel Gresley	A1	A1 & A10	A10	April 1922	December 1924	July 1927	December 1948	52	1 Flying Scotsman as an A3

Loco Weight	Tender Weight	Driving Wheel	Boiler Pressure	Cylinders	Tractive Effort
92 tons 9 cwt	57 tons 18 cwt	6' 8"	180lb/sq in SU	Valve Gear: Walschaerts (piston valves) Three 20" x 26"	29,835 lb
93.93 tonnes	58.83 tonnes	2.03m	1241.06 kPa	0.51m x 0.66m	132.71 kN

[edit] Description

The Great Northern Railway's (GNR) 4-6-2's were the brainchild of Nigel (later Sir Nigel) Gresley, who became Chief Mechanical Engineer of the GNR in 1911. The concept represented by these famous 4-6-2's was that an engine with ample capacity for the job at hand was more economical to operate.

The first of the Gresley-designed A1 steam locomotives was placed into service in the GNR in April 1922 and was somewhat of a milestone, as seventy-nine of the class were ordered between 1921 and 1934. In the 1923 Grouping, the GNR became part of the newly-formed LNER with Gresley continuing as Chief Mechanical Engineer.

The first ten of the A1 steam locomotives cost an average of ₤8,560 compared to the ₤6,840 for each of the first ten GWR Castle Class.

The A1 Pacific steam locomotive had 3 cylinders: 2 on the outside and 1 in the middle connected to the middle driving wheel. Gresley was as much artist as engineer and gave the locomotives an aesthetically pleasing design, decking them out in an attractive livery and giving them evocative names, mostly taken from racehorses of the era.

In contrast to their graceful appearance they suffered from a number of engineering problems. They had a stiff "all or nothing" regulator which, combined with the absence of any compensating levers near the rear pony and driving wheels, made them liable to slipping. This tendency to "wheel burn" resulted in the rails having to be changed every few weeks at points where the A1s habitually started from rest.

A tendency for the "big end" of the connecting rods to run hot seemed quite chronic, yet those of comparable locomotives of other companies never gave more than occasional trouble. There were also such significant faults as broken lubricator pipes, which could only be replaced by lifting the boiler off the frame.

Between 1927 and 1947, all of the A1s were rebuilt as A3s, with the exception of No. 4470 Great Northern, which was rebuilt by Edward Thompson in 1945 as Class A1/1. In 1945, Thompson redesignated the remaining A1s as Class A10. In 1939, one of the A1s (1468) was rebuilt at Crewe with new curving footplate, square off side windows, unique square buffers, Stanier two-cylinder motion and Walschaerts valve gear (check the crooshead in two slide bars), and then supplied with a six-wheel LMS-style tender to replace its eight-wheel GNR tender. In 1956, it was rebuilt with a square Belpaire firebox and removed an LNER chimney and dome. The boiler was then re-shaped with the firebox given a wide square base. The Stanier top feed, dome and chimney were fitted although it is still A1 boiler and has a A3-style cab.

[edit] Individual Locomotive Details

LNER Number	1946 LNER Number	BR Number	Name	Into Service	Rebuilt	Notes
4470	113	60113	Great Northern	April 1922	September 1945	Rebuilt to A1/1
4471	102	60102	Sir Frederick Banbury	July 1922	October 1942
4472	103	60103	Flying Scotsman	February 1923	January 1947	Preserved
4473	104	60104	Solario	March 1923	October 1941
4474	105	60105	Victor Wind	March 1923	October 1942
4475	106	60106	Flying Fox	April 1923	March 1947
4476	107	60107	Royal Lancer	May 1923	October 1946
4477	108	60108	Gay Crusader	June 1923	January 1943
4478	109	60109	Hermit	July 1923	November 1943
4479	110	60110	Robert the Devil	July 1923	August 1942
4480	111	60111	Enterprise	August 1923	July 1927
4481	112	60112	St Simon	September 1923	August 1946
2543	44	60044	Melton	June 1924	September 1947
2544	45	60045	Lemberg	July 1924	December 1927
2545	46	60046	Diamond Jubilee	August 1924	August 1941
2546	47	60047	Donovan	August 1924	January 1948
2547	48	60048	Doncaster	August 1924	May 1946
2548	49	60049	Galtee More	September 1924	October 1945
2549	50	60050	Persimmon	October 1924	December 1943
2550	51	60051	Blink Bonny	October 1924	November 1945
2551	52	60052	Prince Palatine	November 1924	August 1941
2552	53	60053	Sansovino	November 1924	September 1943
2553	54	60054	Manna	December 1924	July 1943	Renamed Prince of Wales on 11th November 1926
2554	55	60055	Woolwinder	December 1924	June 1942
2554	55	60055	Woolwinder	December 1924	June 1942
2555	56	60056	Centenary	February 1925	August 1944
2556	57	60057	Ormonde	February 1925	January 1947
2557	58	60058	Blair Athol	February 1925	December 1945
2558	59	60059	Tracery	March 1925	July 1942
2559	60	60060	The Tetrarch	April 1925	January 1942
2560	61	60061	Pretty Polly	April 1925	May 1944
2561	62	60062	Minoru	May 1925	June 1944
2562	63	60063	Isinglass	July 1925	April 1946
2563	64	60064	William Whitelaw	August 1924	November 1942	Renamed Tagalie on 2nd July 1941
2564	65	60065	Knight of the Thistle	August 1924	March 1947
2565	66	60066	Merry Hampton	August 1924	December 1945
2566	67	60067	Ladas	August 1924	November 1939
2567	68	60068	Sir Visto	September 1924	December 1948
2568	69	60069	Sceptre	September 1924	July 1942
2569	70	60070	Gladiateur	September 1924	January 1947
2570	71	60071	Tranquil	September 1924	October 1944
2571	72	60072	Sunstar	September 1924	July 1941
2572	73	60073	St Gatien	October 1924	November 1945
2573	74	60074	Harvester	October 1924	April 1928
2574	75	60075	St Frusquin	October 1924	June 1942
2575	76	60076	Galopin	October 1924	June 1941
2576	77	60077	The White Kight	October 1924	July 1943
2577	78	60078	Night Hawk	October 1924	January 1944
2578	79	60079	Bayardo	October 1924	May 1928
2579	80	60080	Dick Turpin	November 1924	November 1942
2580	81	60081	Shotover	November 1924	February 1928
2581	82	60082	Neil Gow	November 1924	January 1943
2582	83	60083	Sir Hugo	December 1924	December 1941