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Edward Thompson: Wartime C.M.E. Discussion

Discussion in 'Steam Traction' started by S.A.C. Martin, May 2, 2012.

  1. 35B

    35B Nat Pres stalwart

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    But they aren't building a new locomotive to do the job that the P2s were needed for in WWII. I have no problem with that project - which is an expression of WIBN enthusiasm, not commercial need - following the original pattern, while also accepting that with the information, time and resources available in the 1940s, Thompson's decision to rebuild was entirely reasonable and rational as a way to get valuable assets back into productive work.
     
  2. MellishR

    MellishR Resident of Nat Pres Friend

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    Has it ever been conclusively established how much trouble, if any, was due specifically to the long rigid wheelbase rather than to other factors such as the non-optimum pony truck?
     
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  3. Steve

    Steve Resident of Nat Pres Friend

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    It's quite a simple answer. If they didn't build the replica essentially to Gresley's design, they wouldn't be building a P2. I regard the P2's as being poor but I'm quite interested to see one, as I suspect most people are; just like I'd like to see a J39 and a B17.
     
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  4. Kylchap

    Kylchap Member

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    Many of the locomotive classes that, with hindsight, are seen as successful were not initially so. A period of trial and development was frequently needed before a satisfactory locomotive was produced: Gresley's original A1, a much revered class, was not successful until the later introduction of long travel valves; Bulleid's pacifics had shortcomings until rebuilt by BR; etc.

    The P2s were never fully developed to iron out their failings. As a small class, they seem to have been overtaken by the higher priority of developing the Gresley pacific classes. Thompson attempted to sort out the mikados, within the constraints of his time, by rebuilding them as pacifics. The approach taken with the new-build P2 is to show that Gresley's concept could have been (and will be) the basis for a successful and very impressive locomotive, given the development that other classes enjoyed.

    I feel hopeful that the new P2 will be a revelation in the same way that the rebuilt 71000 was over the locomotive that BR produced.
     
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  5. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    I think there is a danger here that two separate things are being conflated in order to:

    a) deliberately make Thompson's decision-making look suspect

    or

    b) make the P2 Trust's decision-making look suspect

    Which is not fair on either party? So, let's get that elephant out of the room: stop doing that. It's as nonsensical as it is unfair to try and compare the modern-day new build Prince of Wales with the original P2s.

    Not only that, it is utterly bizarre to try and conflate the two separate buildings of a new locomotive: one which has the benefit of a further ninety years’ worth of locomotive design, materials engineering and the rise of computer aided design and modelling, with the basic pencil and paper, compared with the austerity driven approach that the men of Doncaster Works were faced with in 1942 when the drawing office was originally asked to redesign the P2 locomotives to suit a Pacific layout.

    Prince of Wales, in any event, will not be doing the same sort of work as the P2s in any way, shape or form, and will be operating on a railway where the tighter curves are largely being smoothed out as much as possible. It’s a much better railway in 2020 than it was in 1941.

    So with that in mind, let’s return to the basic question of: why did Edward Thompson rebuild the P2s?

    Please look at the statistics below which show the change over period of the P2 rebuilds.

    upload_2020-2-7_12-2-42.png

    As you can see, in 1942 and 1943, the P2s had around 50% availability and were all well short of their intended 70,000 miles per annum figures.

    It doesn’t matter whether you think it was the conjugated valve gear, the maintenance regime, or what: the basic fact is that the P2s were not meeting the requirements that the LNER had set them.

    When I started researching the book, and started looking into the P2s, I was fortunate that other, better, writers had already done a lot of research, and that the P2 Trust had done an amazing analysis of the issues that likely were encountered by the LNER originally.

    To sum up, those issues were:

    · Pony truck was not guiding the driving wheels into the curves

    · This likely led to overheating axle boxes and uneven wear

    · The crank axle was the original A1 type design, used without modification

    · Several of these crank axles had failed at slow speed with high strain

    So, combine the above known issues with the availability and mileage figures. Is this a good picture of the P2s? Abundantly, no.

    You don’t even need to talk about Edward Thompson in relation to the P2s’ rebuilding. Remove him from the equation altogether, in fact.

    The money men run a railway company, not the CME.

    The CME accommodates and facilitates the running of locomotive and rolling stock on a railway for the express purpose of turning a profit and keeping the railway going.

    So, it must be understood that the CME must justify any additional expenditure. If you have one class of locomotive that is out for repairs more often than others, they are going to come up on the radar of the board of executives. Why are we paying out so much money to run these locomotives? Can we build something else to replace them?

    For a very long time we’ve had dismissals of Thompson for his decision making, but I think the truth is that the P2s could quite conceivably have been scrapped altogether instead – and nobody would have batted an eyelid on the LNER.

    You might get a few misty-eyed railway enthusiasts and a couple of drivers who knew what they were capable of, complaining, but outside of that nobody is going to care about six non identical steam locomotives that weren’t performing very well, getting scrapped.

    It’s not about the exceptional one off prodigious hauling feats, or how good it looks: it’s about doing the same work, day in, day out, for years on end, reliably and at minimal cost to the railway – and ESPECIALLY in 1941 when the war was two years old, the big bombing raids were just starting, and Britain was in a position that might be politely described as “up the creek”.

    Any time out for repair of any steam locomotive is going to have an impact on services.

    There is an argument that has been put to me that building six new V2s might have been a better bet than rebuilding the P2s.

    However, there is a crucial point in that the boilers of the P2s were considered sound enough to be retained. Boiler repairs took up a lot of workshop capacity, over and above other repairs, so if you can manage to make locomotives go longer on their boilers, you end up managing to squeeze more workshop time for other things. Thompson actually changed the sheds and workshops’ approach to shopping locomotives by insisting on having boiler inspectors look at engines before they were approved for shopping. This meant that repairs that could be done on shed were done instead of being sent to the major works where capacity was incredibly tight.

    (Remember that the LNER had given over about 90% of its actual foundry and workshop capacity to building aircraft, munitions and vehicles for the war effort and you start to realise that the LNER were possibly the most constrained railway company in the second world war – inheriting as they did, the oldest fleet on average due to the combination of railway companies they were formed with in 1923, and adding new locomotive classes in addition to those existing, and not withdrawing, many older classes throughout the next twenty years).

    Thompson put the W1 on test to compare with the P2s on their own work and this locomotive, with high tractive effort and six driving wheels, compared favourably before returning south. It is this which I think made up Thompson’s mind to rebuild them prior to the Cox report being published to the board.

    The Cox report confirmed his thoughts on the way forward, and I think we have enough substantial contemporary statistics to show that the issues on the LNER were not imaginary, nor overplayed by Thompson in any way.

    Thane of Fife was the worst P2 and became the best A2/2 in its life. When you look at the tables above, and note its improved mileages and availability after rebuilding, including an extraordinary 93% availability in 1946, then I think you can say with absolute certainty that Thompson made the right decision – not necessarily for the potential of the P2s – but for the LNER.

    His job in the middle of world war two wasn’t to experiment with different pony trucks, repeated attempts to make the conjugated valve gear more reliable, nor was it his job to be Sir Nigel Gresley – his job was to make sure the LNER had locomotives that were more readily available for work than not.

    The A2/2s achieved this. Rebuilding to a Pacific outline was an entirely safe route of engineering. All I know is that, with the engine cards in front of me, their availability statistics (now virtually complete up to their withdrawal), the A2/2s were better motive power for the LNER as Pacifics than they were as Mikados. They did better mileages, they were more available for work, they cost about a third of a new V2 to convert, and they had longer lives than they did as P2s. They provided excellent return on their investment.

    That, when all is said and done, is what ultimately matters to a railway company.

    ***

    So, what about building a new P2? I am a founder member of Prince of Wales. Why should we build a new P2?

    It’s simple to me. The original locomotives were a magnificent spectacle. They had great potential for development. World war two, however, intervened.

    There was not much appetite for developing them in any event – prior to the war, their availability and mileages were modest, and the newer A4s were performing very well indeed. They made up a tiny percentage of the work that the other larger classes did. It could be argued, cogently, that Gresley didn’t develop them further or see a need to “fix” any issues because they were such a small class, doing peripheral work compared to that of the A3s and A4s found in Scotland and England.

    Throw in the V2s as well, which I don’t think anyone would disagree were a roaring success for the LNER, and the desire/need to do something about the P2s falls away.

    So why build a P2 now? We have the advantages of history and engineering development. We observe that Thompson used the Stanier O6 pony truck on his loco designs and applied it to the V2s for rebuilding. This design has been used in the development of the new Gresley P2, together with computer analysis of the ride quality of the locomotive.

    The locomotive that is being built is not really a Gresley P2 in the true sense of the word. Like Tornado, it is a further development of a design: and design ethos, that comes from the past. People were enticed by the mythology around the P2s – likely helped by the (mostly untrue and unfair) things said about Edward Thompson and the rebuilt locomotives.

    Whatever anyone’s personal reasons are for wanting one, there’s no justification really for building new steam locomotives of any design in the world – we have moved on.

    But if you are going to build one, and it is going mainline, of course you are going to update it, and make it as best you can for the quality of railway that we have today. That is obvious.

    The advantages of a Mikado layout are well known, adhesion, high power, etc. The P2s had other advantages such as the excellent steam circuit and Kylchap arrangement. The choice to build and original, CoTN style loco is purely for PR purposes, in my opinion, and I wholeheartedly support that as it is a magnificent looking locomotive.

    ***

    I hope the above has not been too much of a Groundhog Day for you all and explains my thoughts and the material available.
     
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  6. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    I don't know the direct answer to this, and I am sure someone from the P2 Trust will be more readily able to answer: however I am not convinced that the wheelbase was actually the issue that it was made out to be.

    I say this because I can find no direct criticism of the wheelbase by anyone internally on the LNER: all of the criticism is directed at the conjugated valve gear, crank axle, axleboxes and pony truck where the P2s are concerned.

    There is, so far as I can see, no official reports of the wheelbase being an issue on the lines they worked on. There are some stories of course, but not from official sources, only from LNER writers who were writing long after the events.

    Far more cogent are the contemporary availability statistics and reports on the A2/2 comparison. The criticisms are mechanical, not wheelbase, related.
     
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  7. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    I think Tom - as always - sums it up fair more concisely and cogently than I ever could.
     
  8. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    The thing the P2 does have on its side is the potential to be something very special. The adhesion along together with the boiler capacity, and the revised cylinders and valve gear are likely to make a very potent machine that can do anything thrown at it in preservation - it will never do the sort of work the P2s did, after all. The argument for building one was not based entirely on "from the head" thinking but very much "from the heart" where those of us who wanted to see one (myself included) were concerned.
     
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  9. MarkinDurham

    MarkinDurham Well-Known Member

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    Regarding the frames; wasn't it simply that the P2's frames were just too long for Doncaster to produce in one piece?

    Regarding the original valve gear on 2001; ISTR that the cutoffs were stepped, which obviously limited the fine adjustments usually available to drivers. The gear being fitted to 2007, being infinitely variable, resolves that issue, does it not?

    Mark
     
  10. Eightpot

    Eightpot Resident of Nat Pres Friend

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    Perhaps I could bring to your attention, Simon, in case you are not aware of it, but 2005 was the only P2 that had a single chimney rather than the Kylchap arrangement that all the others had. In the light of the improved performance of the A3s and A4s being so fitted in the late 1950s this would explain as to why 2005 did not match up to the rest of the P2s.
     
  11. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    I am aware, but it is always good to have a reminder. :)
     
  12. Spamcan81

    Spamcan81 Nat Pres stalwart

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    You are correct. Stepped cut offs led to the problem of one setting not being sufficient but the next step up being too much.
     
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  13. LesterBrown

    LesterBrown Member

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    I have no doubt that there would be a certain amount of support for a replica original Drummond T14 too, despite its shortcomings, after all the idea of a new build Claughton keeps get resurrected too. Although a less successful loco than the 4700 a P2 will certainly be more useful and popular as a heritage loco (and I say that despite the 4700 being one of my favourite locos).
     
  14. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    The more I read on the lentz gear the more I am acutely aware of how difficult a job it would have been to be a designer in the steam era. We take for granted the computer analysis we have now. Valve gear designers, whether you deem the fruits of their labours successful or unsuccessful, were still brilliant mathematicians and engineers quite frankly.
     
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  15. Steve

    Steve Resident of Nat Pres Friend

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    Did the P2's have the same limited maximum cut-off of 65% that Gresley insisted on with the A4's? (Not sure if this was the case with the A1's & A3's, as well.)
     
  16. M Palmer

    M Palmer Guest

    I found the following entry on steamindex which I thought might be pertinent to the conversation:

    http://www.steamindex.com/locomag/lcwr50.htm


    Apparently, this is to be found in the August 1944 Locomotive (etc) Magazine. A quick trawl through my various files including the relevant RCTS tome reveals no 2-8-2 with wheel sizes between the V2 & P1. Was this a serious proposal, a notional "traffic study" as it were or one of those editorial articles that tell industry how they should be doing it? Given that the LNER was in the process of ridding itself of 2-8-2s in the period of writing, surely it must be one of the latter two?
     
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  17. jnc

    jnc Well-Known Member

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    Which I expect means the conversions used a lot less resources than new V2's would have - a critical concern at that point in time, I'm sure.

    I hope a lot of this note winds up in the book (if it's not already there), because a lot of readers may have the same question (s), and this note clearly and concisely explains why.

    Noel
     
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  18. Eightpot

    Eightpot Resident of Nat Pres Friend

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    I can think of of a couple, the Prussian/German P10, later DR BR 39 with 1750 mm (5' - 8.9") driving wheels, also the DR BR 41 with those of 1600 mm (5' - 2.9"). A close contender would be the former Saxon 2-8-2 XX HV, later DR BR 19 with 1905 mm (6' - 3") diameter ones.
     
    Last edited: Feb 7, 2020
  19. jma1009

    jma1009 Well-Known Member

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    An interesting debate over the last 24 hours or so, and I am partly persuaded by a lot of the detailed posts...

    Except, and one always ought to consider the bigger picture, why did Thompson continue building V2s? That expensive monobloc cylinder casting, and that condemned conjugated gear! Expediency?

    Cheers,

    Julian
     
  20. Fred Kerr

    Fred Kerr Resident of Nat Pres Friend

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    1. They were available
    2. They coped with the duties expected of them
    3. They proved more capable than their classification allowed (e.g. proving as capable as an A3 on passenger duty)
    4. They were well known to drivers over most of the LNER network - except the ex-GER lines

    Note also that Thomson used the materials for the last 4 V2s (60985-88) to build 4 A2 Pacifics (60507-10) so even the V2 specification wasn't above major re-design.
     
    Last edited: Feb 8, 2020
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