The LNER A classes

I've now seen examples of classes A1, 2, 3 & 4, but never saw them in BR or LNER days. Now I understand the A3 was a development (improvement?) of the A1s and the A2s were a rebuild of the P2s, but can anyone give a bit more info please?

For example if a train was heavier than usual, would an A3 be provided instead of an A4?
If the train would be delayed south of Donny due to P/W work, would an A4 haul the train to recover lost time through better acceleration etc? Or was there so little difference between the classes TopShed would simplyalocate "a Pacific" for certain duties?

Then of course there was the A5 class. A Pacific tank was not too common in Britain. Were these designed & built as an experiment or for a specific role or set of duties please?

 

Hi, suggest you start HERE

 

Hi,
Yes the A3 was a development of the original Gresley A1 and earlier A1s were converted to A3 standard in due course. The Thompson A2 class was a mix of rebuilt P2, V2 (converted on the production line as they were being constructed) and new build to Thompson's design. The Peppercorn A2 class was a development of the Thompson A2.
The A5 was a GCR suburban tank design.
As for which class would be rostered for any given diagram, obviously the non stop Kings Cross - Edinburgh runs required a loco with a corridor tender. Initially this would have been an A1 or an A3 but after all the corridor tenders were affixed to A4s, this working became an exclusively A4 diagram. Other top link expresses could to all intents and purposes be worked by any of the LNER Pacifics or a V2 even.

 

In the final years of steam on the ECML the heaviest trains would usually be rostered for a Peppercorn A1. They also worked one of the fastest trains, 07.50 KX - Leeds. New England's A2s had a turn on the down Flying Scotsman in the late 1950s. The summer only non-stop was always an A4 duty, but apart from that the other Pacific classes were more or less interchangeable, with the V2s helping out at busy times. There were only 34 A4s out of a total of 202 Pacifics and even they took turns on freight work such as the afternoon Scotch Goods, 266 Down, as well as the overnight sleepers.

The A5s tanks were used on suburban services from Marylebone until replaced by L1s from 1949 onwards.

 

And A8s worked around Whitby

 

Just to add to what has already been said, there was a post grouping batch of A5s built for (I think) work in NE England. It was one of two Robinson designs to be used for early LNER requirements, the other being the D11 "Director", a number of which were built for use in Scotland.

There were so many LNER Pacifics available in the 1950s for several A3s to be allocated to Leeds (Holbeck), which was an ex-LMS shed. They worked expresses over the Settle and Carlisle line. A3s and V2s worked (interchangeably I think) on the GC in the 50s, until the LMR took full control.

The A2s were supposed to be a new type of standard Pacific, a successor to the V2, but ultimately there were four versions of the loco. The four that would have been the last V2s were described as the "orphans of the storm" by Edward Thompson, which shows that he was well aware of the ruckus his regime was causing. That was a pity, because the B1, although prone to appalling riding, was a very good value loco, as were the O1 rebuilds.

One thought - when Thompson needed to dismantle an A1 to allow him to produce what was effectively a new Pacific (there was very little of the original Great Northern in the "rebuild"), there were still I think eight or ten A1 spec Pacifics, one of which was 4472 - it was not rebuilt as an A3 until 1948.

 

The destruction of 4470 is something for which Thompson will never be forgiven amongst Gresley aficionados.
Further to 50002 mentioning the Scotch Goods, this was a top link passenger working and there are tales of Bill Hoole driving this in much the same manner as when he was on an express passenger.

 

Further info that may be of interest : Sadly many forgot that Thomson was peeved because the post of LNER CME should have been offered to Raven as next senior to Robinson thus Thomson - as Raven's son-in-law would have been expected to follow in the post when Raven retired in 1926. Fortunately Robinson recommended Gresley to the LNER Board and this recommenndation was adopted. Proof of the wisdom can be shown by noting that on Thomson's A1 he insisted on placing the outside cylinders between the driving wheels and the front bogie ( as per NER practice ) rather than the proven Gresley design of placing them between the wheels on the front bogie. The Thomson concept both lengthened the A1 and made it more rigid than was needed and tended to confirm the anti-Gresley mood of his tenure. In an interesting parallel Raven had built a Pacific prior to the 1923 Grouping numbered 2400 of which 5 were built. Gresley classified these A2, the linesiders nick-named them "skittle alleys" and Gresley tested the 2 Pacific designs against each other. The Raven A2 proved inferior to the Gresley A1 and lasted only until 1937 by which time all were withdrawn.
The story is told that Thomson intended his new A1 to work on the Edinburgh - Aberdeen route for which suitable power had always been difficult to source and sent it to Haymarket to initiate trials. It was reported that the A1 was immediately returned south with a curt note from the Haymarket shedmaster stating that "Haymarket depot is a Gresley depot - and will stay that way whilst I remain in post". In later years the V2 proved to be the answer and - interestingly - its 7MT classification places it above the A3's 7P6F classification.

 

Is there any real hard evidence for these much repeated assertions about Edward Thompson's motives? Someone must have done psychological profiling I suppose?

Re the V2s, my 1958 combined volume ABC gives their power classification as 7P6F not 7MT. On the same basis the A2s, except for the A2/1 variety, would have been best suited to the Edinburgh - Aberdeen route because they were rated 8P7F.

 

Had the NER continued as a separate entity, Thompson would have succeeded to the "top job" in 1936 I think. That may have played on his mind, and also of course he was not made CM&EE of the LNER, but CME, ie without the electrical part of the job.

Having said that, he came to the job in the middle of the war and with maintenance proving a problem. What he got wrong was going in for rebuilding locos to eliminate the middle cylinder (or convert locos with the "Gresley Gear" to have three sets of Walschaerts), when Cook showed in the 1950s that there was a far better solution - assembling the middle big end differently.

What Thompson got right was that, in an environment where maintenance might be indifferent at best, middling size locos with just two outside cylinders were a better bet - this is one of the ideas that Riddles and his team adopted for the BR Standards, with 71000 being the sole exception.

Some of Thompson's actions, like the P2 rebuilds, were controversial, although I've heard that the Civils would have banned the locos north of Edinburgh had they been left in service. The solution would have been to sort the leading pony truck, for which Thompson had an alternative type ready to go, rather than rebuilding.

The placement of the outside cylinders on the Thompson Pacifics I believe came from his insistence on using equal length connecting rods. This was something he got from GWR practice, as was the use of a 225psi boiler pressure.

Fans of Arthur Peppercorn might note that he continued much of what Thompson had laid out: the "production" A1 is only different to the "rebuild" of Great Northern in the area of connecting rods and outside cylinder placement - same with the Peppercorn A2s versus the Thompson ones. He also continued the use of the B1 as a standard type, and based his K1 on the Thompson K4 rebuild. And the O1 conversions continued.

Peppercorn did however stop conversions of B17s to B2s, on the basis that it wasn't worth the outlay.

 

That is simply not true. It's a pity people do not check their facts before posting. After the P2s were rebuilt as Pacifics they worked north of Edinburgh for several years. It was not until at least 1949 that they were transferred south and replaced by Peppercorn A2s.

 

If you reread Tim Fenton's message I think that you will find he was referring to the P2s being banned north of Edinburgh had they continued in service.

 

Indeed - the information I got was that the locos would have been banned *as P2s*. It was all to do with the suspicion that they were causing road spread.

As Pacifics, they had neither the two wheel leading pony truck, nor the eight coupled wheelbase, both thought to be potential causes.

But the rebuild wasn't a good idea: the locos emerged with a lower adhesion factor and had a bad reputation for slipping.

 

In one book I read, a Scottish driver was quoted as saying "they'd slip on Mussleburgh sands." Nuff said I reckon.

 

OK, I understand now what you meant, but I still don't buy it. The P2s worked on the Aberdeen route for several years before Gresley's death in 1941, and even after that under Thompson it took another 2 years or more before they were rebuilt as Pacifics. If they were causing that many problems, why not move them or rebuild them immediately?

 

Moving them on to the GN to help with the monster wartime loads would have been a good idea according to several articles I've read and I happen to agree. As for why they weren't rebuilt immediately, one assumes Thompson had quite a bit on his plate at the time and the design work needed had to take its place in the queue.

 

My understanding was that the P2s were difficult to handle therefore it was best to keep them on the (Edinburgh - Aberdeen ) route where they were best known; their coal consumption was known to have them nick-named "The miner's friend". Whilst possibly good pullers on the trunk ECML route south of Newcastle their heavy coal consumption may have created problems that were not needed at a time of such criticality.
Whilst not denying that the changed situation at Gresley's death ( i.e. lack of maintenance, need for greater work periods, hauling heavier loads ) necessitated drastic action there are always thoughts that Thomson could have been less dramatic in his changes and the choice of rebuilding Gresley's first Pacific 1470 when others were available to rebuild simply reinforces the view that Thomson was out to demonise Gresley ideas rather than develop them.
It is also fair to point out that Peppercorn took over when the threat of Nationalisation had become real and therefore he had to simply fill the gap until Riddles became the BR CMEE; in this context the redesign of the A2s to the shorter wheelbase by restoring the cylinder location to between the bogie wheels proved sufficient to provide a suitable loco for use on the Aberdeen - Edinburgh route with 11 of the 15 locomotives from that batch being allocated to sheds on the route by 1950.

But reverting to the original question there were several A (4-6-2) designs namely

A1 Original Gresley Pacific with 180 psi boilers built 1922
A1 Thomson 1945 rebuild of Gresley Class A1 (A10) 1470 built 1945 (60113) followed by Peppercorn redesign (60114-62)
A2 Raven Pacific introduced 1922 withdrawn 1937 - LNER No 2400-04
A2 Thomson rebuild of Gresley P2 ( 60501-06), followed by new build using V2 boilers (60507-10), followed by new build based on 60507-10 (60500 + 60511-24). The final batch were Peppercorn redesign (60525-39)
A3 Original Gresley A1 fitted with 220 psi boilers
A4 Improved Gresley A3 fitted with streamlining
A5 Robinson Tank design of 1911 built for service in Lincolnshire / Yorkshire routes of GCR (69800-29) with a further batch of 13 (69830-42) built by Gresley for services in Darlington area.
A6 Raven 1914 rebuild of Worsdell's 1907 Class W 4-6-0T (69790-99)
A7 Raven 1910 design built for Hull area local services (69770-89)
A8 Gresley 1931 rebuild of Raven Class D 4-4-4T for Hull - Scarborough - Whitby area services (69850-94)
A9 not allocated
A10 short term classification of A1 locos not rebuilt to A3 whilst Thomson / Peppercorn A1s were being intoduced

 

The coal consumption of the P2s was partly attributed by Bulleid to the relatively short runs they did. It would be useful to compare their appetite for coal with Pacifics and V2s doing similar turns - and compare single heading with single heading (part of the rationale for the P2s was to attempt to eliminate double heading between Edinburgh and Aberdeen).

 

So there was a debate about whether the pony truck or the wheelbase was to blame for the poor riding. I didn't know that, thought it was the 2 of the 2-8-2.
Was the debate resolved?
I hope so because as far as I know (from these boards) the A1 society are intending to use a tried and trusted Stanier 8F-type leading truck for their proposed P2, but the driving wheel arrangement will be as-was.
It would be ironic if number 2007 were to appear and then get banned from its auld haunts north of Edinburgh because of its long wheelbase. I assume that mainline running on modern large-radius curves further south would be no issue.