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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. Hermod

    Hermod Member

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    I have a BR class 5 test report somewhere and if someone can guide me to a web place for the corresponding B1 one we can compare form (with 2- sometimes three digit accuracy.
     
  2. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    There's a lot to unpick here, but I think this post shows the difference between enthusiasts talking about, and desiring perfect locomotive performance after the event, and design teams and CMEs living the issues and running a railway at the time.

    I didn't "launch off" - I questioned your reasoning. Not the same thing.

    If it ain't broke...! The smokebox arrangement may not be perfect engineering but in day to day use it worked perfectly well for what it was intended to do.

    Why would you ring up anyone else if the arrangement you had worked? It might not have been as good as found elsewhere, but it didn't stop the locomotives fitted from doing their day to day work. Ultimately the CME's job is about asset management and (particularly in the LNER's case) providing tools that can do the jobs asked of them. In the middle of world war two, I highly doubt that Thompson or anyone else for that matter, would have stopped using something perfectly adequate for the job required.

    They didn't have time to go into a deep seated exploration for the ultimate performance machine: they were running a railway and in practical terms, a locomotive that is reasonable and does the work, and is cheap to build, is as good (perhaps better economically) as something highly capable.

    I think Bulleid probably had a pretty good idea of what he was doing. How many Bulleid Pacifics are preserved? We know what they are capable of. He and Thompson (as Tom has said previously) saw the same issues of maintenance and had different ways of dealing with them. I personally now have a much better understanding of chain driven valve gear than I did before and I see what he was trying to do. The locomotives seemed perfectly capable but were hamstrung by the quality of materials available at the time - certainly and evidently hampered by WW2.

    I rather feel that you are dismissing the context of the time and focusing purely on pure performance, which wasn't their aim at the time - at all. In the LNER's case, having adequate numbers of locomotives with better availability to do work was far better than having scores of locomotives which could in theory do excellent work but had low availability.

    You miss the practical and economic cases I am afraid.

    So here is your argument Julian:
    • Gresley Pacifics had flimsy frames
    • Thompson continued this policy of thin frames
    • Thompson should have been aware of this
    My response is:
    • The first Gresley Pacifics did have 3/4 frames renewed in their lifetimes due to the frame design
    • Class A4 had a different frame arrangement (stays/widths changed) - did not suffer anywhere near as much as the original Pacifics
    • After class A4, frame widths changed a little with the later Pacific classes
    • Frame cracking and issues with frames were not seen on class A4
    • Class A2/2 suffered disproportionately (as they had done as P2s) due to the split frame arrangement (far more important than the difference in thickness)
    • All locomotives built post A2/2s to new designs did not suffer frame issues anywhere near as much as the original Gresley A1s had
    The point I would make is that the desire for ultimate locomotive performance we see in enthusiasts talking after the event, doesn't take into account the context of the time.
     
  3. Cartman

    Cartman Well-Known Member Account Suspended

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    Briefly, on A3s, i have read somewhere that they found the Waverley route a bit of a challenge with its curves and gradients and were better on the East coast main line as they were intended for fast running
     
  4. sir gilbert claughton

    sir gilbert claughton Well-Known Member

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    the Claughton had 6'9" drivers .

    my comment was really to say that they would have been better as a 4-6-2.
    that would probably have kept mr Trench happy by reducing the axle loading a tad , and avoided the rear axle heating issue , and as a bonus , made a better front end possible .
     
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  5. sir gilbert claughton

    sir gilbert claughton Well-Known Member

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    couple of points re preceding posts

    one of the early Claughtons took a lump out of the platform facing at Bletchley - hence the cutaway in the buffer beam .

    the B1 when on test was found to have extremely good cylinder efficiency - which infers the draughting was pretty good too .the front end exceeded the ability of the boiler to make steam , which is the opposite of most locos ,where the cyls are the limiting factor
     
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  6. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    So this. Well said Tom.
     
  7. bluetrain

    bluetrain Well-Known Member

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    It seems curious that successful steam locos had such a wide variation of proportions between the sizes of boiler, grate, cylinders and so on, with a lot of trial and error to find an optimum solution. Engineers nowadays will have a lot of computer power and software to help out, but "back in the day" it was pen, paper and logarithm tables (remember them?).

    Some examples are quite extreme. The Midland compound had only a 4ft 8in boiler, but grate about the same size as the much larger Schools class. The LNER (ex-NER) J27 0-6-0 by contrast boasted a 5ft 6in boiler but grate of only 20 sq ft.

    When McIntosh of the Caledonian wished to produce a more powerful version of the Drummond 4-4-0s, he initially increased the boiler diameter in the Dunalastair I and then lengthened the boiler barrel in the Dunalastair II, while keeping the grate almost the same size. Meanwhile Drummond himself had moved to the LSWR and introduced the C8, which was a clone of the 4-4-0s that he had built for the NBR & CR. Like Mcintosh, he also then wanted more power, but the most obvious change from the C8 to the T9 is that the firebox & grate became a foot longer. Strange thing is that both McIntosh & Drummond were successful! I suppose that coal quality may have had something to do with it - the Caledonian was sitting on its own coal supplies but the LSWR had to get them from elsewhere.

    And returning to the LNER and Mr Thompson, I assume that the Thompson and Peppercorn pacifics had larger fireboxes and grates than their Gresley predecessors because of an expectation that even top-link engines would in the future have to make do with coal of poorer quality.
     
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  8. jma1009

    jma1009 Well-Known Member

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    Hi Simon,

    Just few points for tonight, I don't agree the A4s had no frame problems. Not on everyone's radar is Don Young's autobiography '50 Years with Steam'. If you can't get a copy I can send you mine or photocopy the relevant pages to send to you. He was an apprentice at Doncaster and then transferred to Eastleigh. He then became extremely well known as a designer of miniature steam locomotives.

    (And Don's 5"g 'Doncaster' design of the Gresley Pacifics ditches the LNER irregular and badly proportioned petticoat pipe in favour of a Sam Ell type profile - though it does not quite conform to the Ell formulae).

    I found a copy of Professor Young's book on smokebox draughting in Cardiff University Library when I was a student in my teens. It was printed in 1933 and 1936 in the USA. The GWR had a copy as Ell refers to it. Churchward also had a copy of Goss of some 30 years earlier. This is not a 'modern enthusiast using hindsight', but wondering why the LNER and Gresley and Thompson did not appear to know anything of all this. They fitted a few big locos with the Kylchap arrangement, which indicates the basic LNER arrangement for short chimney large diameter somebox locos was not as good as it could have been.

    Cheers,

    Julian
     
    Last edited: May 23, 2019
  9. bluetrain

    bluetrain Well-Known Member

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    Thank-you for the Maffei information sheet on the Romanian pacifics. These locomotives certainly looked different to any other!

    The older generation of British railway writers were impressed with the 4-6-2 locomotives that Maffei built for its local customers in South Germany. They saw them as the "stand-out" German design. I think that I agree with them. I especially like the engine that was painted blue and given a GWR-style chimney.
     

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  10. Eightpot

    Eightpot Resident of Nat Pres Friend

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    As far as draughting goes in pre-Ell times, probably most locos were not as good as they could be - even some GWR ones, too
     
  11. jma1009

    jma1009 Well-Known Member

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    Yes, I am quite happy to concede Eightpot's point in his above post. Collett stuck to Holcroft's 10 standard Goss arrangements from the Churchward period, but they didn't cover the Castles, Kings, and Manors, and it was not till after Collett retired - and pretty much when Hawksworth retired that Sam Ell was able to do the necessary. I have Ell's first 'testing' of 1947 I think.

    But generally, the GWR and the SECR then SR were years ahead (the SECR and SR due to Holcroft going to the SECR from the GWR).

    A bog standard GWR Hall had thicker frames than a Thompson B1, better valve gear events, better smokebox draughting, and better axleboxes, and overall a superior boiler, and the chassis built to a higher 'spec'/tolerances.

    Just because lots of LNER B1s were built does not mean they were perfect.

    Cheers,

    Julian
     
  12. flying scotsman123

    flying scotsman123 Resident of Nat Pres

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    No, but then few locos are perfect, and I don't think anyone's claimed the B1s were either. A loco doesn't have to be perfect to be successful though, and I think the fact that lots were built does at least suggest that the LNER thought they were a success. At the end of the day if I was a designer I'd be quite happy to be successful, perfect is something for the theoriticians.
     
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  13. Hermod

    Hermod Member

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    Strange thing is that these Romanian ugly ducklings were constructed and built same place as the lovely Bavarian S3/6 more or less the same time.
     
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  14. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    That’s most kind, thank you.

    I should have phrased it better - frame issues not to the same extent as the originals. By 50s and Cooks fitting of optical equipment at Doncaster, the A4s were being set up better and much of their problems was being ironed out with forms of preventative maintenance.

    It was on the big locos that the benefits of the kylchap were best felt - in any event a kylchap double exhaust is enormous and you can’t fit it into a B1 smokebox easily!

    The question still remains - why bother reinventing the wheel if you have something that works adequately?

    It’s all a question of economics and practicability. That’s the CMEs role. Neither Gresley nor Thompson thought anything else was necessary on the medium and small engines - Peppercorn reverted to the single chimney on some of his first A2s! And a few carried that fitting to withdrawal.

    The double chimney locos were undoubtedly better but you have to justify the expenditure. By the time you come to this conclusion, the LNER is long gone and nobody is interested, particularly, in developing the LNER classes further.

    ...except for Peter Townend of course.
     
  15. Fred Kerr

    Fred Kerr Resident of Nat Pres Friend

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    But remember that Peter Townsed was managing in a period when no-one wanted to work with "dirty" steam locos hence he had to improve performance and ease his maintenance burden. In parallel with Gresley / Thompson et al he was seeking solutions for the conditions pertaining at the time and many forget this and the specific factors involved.

    In Townsend's case the locomotives were operating high speed long distance trains where his "improvements" showed most benefit through continuous work; had the same "improvements" been applied to the N2s on suburban workings I doubt that the same level of benefit would have been gained.
     
  16. Jimc

    Jimc Part of the furniture

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    That's arguably unfair to Maunsell. The SECR and SR were ahead because Maunsell had the vision to consider improvement possible and to look all around for the best people. Nabbing Holcroft was just a symptom of that. Indeed you could argue that Maunsell underused Holcroft on locomotive design because he was so good at other things like designing works and factory changes.
    You can make an argument that all the big four tended to be a bit too insular.
     
    Last edited: May 24, 2019
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  17. andrewshimmin

    andrewshimmin Well-Known Member

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    What, much too big for the LNW loading gauge...?!?!
    -----
    EDIT: someone beat me to it
     
    Last edited: May 24, 2019
  18. Hermod

    Hermod Member

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    I have found the BR test bulletins for Hall ,V2,B1,Std7 and 8,and LMS class 4(2-6-0)
    The indicator diagrams for Halls look fishy.
    The B1 report has no indicator diagrams.
    Maybe the two outside cylinder-indicator diagrams for V2 can substitute B1 but they look even worse than the Hall ones.
    The former LNER engines used sligthly less coal per work than the Hall over most of the envelopes.
    There is morale somewhere here.
    If somebody has PDFs of Class 5,9 and the two WDs lets swap and disagree.
     
    Last edited: May 24, 2019
  19. RLinkinS

    RLinkinS Member

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    Was the hall an original or one with increased superheat? If it was the original type then you would expect the LNER engines with higher superheat to be more efficient.
     
  20. Hermod

    Hermod Member

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    Most modern Super-Hall
     
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