| LNER Thompson Class A2/1 | |||||||||||||||||||
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.jpg) 60507 'Highland Chieftain' waits for departure at Carlisle in August 1960. | |||||||||||||||||||
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TheLondon and North Eastern Railway (LNER)Thompson Class A2/1 was a class of 4-6-2 steam locomotives built atDarlington locomotive works during 1944. They were originally ordered asClass V2 locomotives, as designed bySir Nigel Gresley, but were revised during construction into a4-6-2 'Pacific' arrangement under the instruction ofEdward Thompson.
At the time Edward Thompson succeeded Sir Nigel Gresley asChief Mechanical Engineer of the LNER in April 1941, Darlington works was busy buildingClass V2mixed traffic locomotives. Although the V2 class were competent and powerful locomotives, Thompson did not like this design as it required more servicing than his own mixed trafficB1 class4-6-0. He also envisaged a time when the V2s would be replaced by his own design of 'Pacific' locomotives, but would not receive authority to build a new class during the war.[1] He therefore decided to build the final four V2 already authorised as experimental 'Pacific' locomotives along similar lines to his recently rebuiltA2/2 class. The revised design was authorised in August 1943 and the new locomotives built between May 1944 and January 1945.[2]
Thepony truck of the V2 class was replaced by Thompson's own design ofbogie and they had an extendedsmokebox. They retained the same boiler as the V2 class although the pressure was increased to 225 psi (1.55 MPa), giving an increasedtractive effort of 36,390 lbf (161.87 kN). Thefirebox was also the same as the V2 although these were the first LNER locomotives to be fitted with arocking grate andashpan. Rather than have all three cylinders driving a single axle Thompson adopteddivided drive with the middle cylinder driving the first pair of driving wheels and the outside cylinders the middle pair. Thompson also abandoned theGresley conjugated valve gear and instead fitted independent sets ofWalschaerts valve gear to each cylinder.
The four locomotives of this design performed adequately but proved to be under-boilered for their size and lacked adhesion. They were less problematic than the A2/2 class, but did not distinguish themselves.[3]
On 17 July 1948, locomotive No. 60508Duke of Rothesay was hauling a passenger train when it became derailed insideBarnet Tunnel,Hertfordshire due to a combination of faulty track and excessive speed. The whole train was subsequently derailed on points atNew Southgate,London. One person was killed.[4]
All four locomotives were withdrawn from stock in 1960/1.
| Year | Quantity in service at start of year | Quantity withdrawn | Locomotive numbers | Notes |
|---|---|---|---|---|
| 1960 | 4 | 3 | 60507/09–10 | |
| 1961 | 1 | 1 | 60508 |
| Original No.[5] | LNER No. | BR No. | Name | Entered stock | Withdrawn | Disposal Date |
|---|---|---|---|---|---|---|
3696 | 507 | 60507 | Highland Chieftain | 13 May 1944 | 12 December 1960 | 31 December 1960 |
3697 | 508 | 60508 | Duke of Rothesay | 30 June 1944 | 20 February 1961 | 28 February 1961 |
3698 | 509 | 60509 | Waverley | 30 November 1944 | 15 August 1960 | 31 August 1960 |
3699 | 510 | 60510 | Robert the Bruce | 15 January 1945 | 21 November 1960 | 30 November 1960 |
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Apple Green Engines produce a ready-to-run model of the A2/1 in 4 mm scale. PDK, Nucast, and DJH also produce 4 mm scale kits of the A2/1. Crownline have produced a 4 mm kit in the past, but this is no longer available.
