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Edward Thompson: Wartime C.M.E. Discussion 2012 - 2021

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

  1. 35B

    35B Nat Pres stalwart

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    Durability of designs, on the basis that this is a proxy for the usefulness of the design. By no means a perfect measure


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  2. ragl

    ragl Member

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    But the railways are and always have been run by accountants, surely costs have the major influence on whether a design sustains. Throughout this thread, every survey carried out by the design/engineering office drills down to the costs, cost is the perfect measure.

    Cheerz,

    Alan
     
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  3. 35B

    35B Nat Pres stalwart

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    Indeed. And the fact that the design lasts rather than being replaced covers that too


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  4. Hermod

    Hermod Member

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    Ravens overfly the rest?
     
  5. Jamessquared

    Jamessquared Nat Pres stalwart

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    There might be something in that. Looking at the graphs I drew for Craven, Cudworth and Beattie, the major part of the graph is sloping at about 3 - 4% replacement per year. At a gross level, that is basically what you would expect if locos have a working life of 25 - 30 years. For a steady state (and accepting that in that era railways weren't quite in a steady state), you can only scrap locos as fast as you can replace them, either by your own construction or buying from external manufacturers. So the budget ran on the basis of 25 - 30 years life from locos, and in a perfect world the workshop would have that replacement capacity. That might mean the capability to construct 10 - 12 engines a year on a small railway like the LBSCR and perhaps ten times as many on a big railway like the LNWR, but the replacement rate would be somewhat similar.

    So no later CME would be able to scrap his predecessors locos on a whim, assuming that those locos were still capable of doing a remunerative job. There would obviously be detailed nuances of why some went early and others hung on, depending on the details of the traffic requirements.

    The real turkeys then are those that are so awful they have to get scrapped well before that planned lifetime is up. A history of locos quietly withdrawn or "rebuilt" after only five or ten years; or new locos set aside through the winter and just used for summer relief - those are areas to probe when looking at a designer's true worth.

    There, managed a whole post without mentioning Drummond. Oh B*ll@cks ...

    Tom
     
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  6. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    In the context of this thread then Tom - would it be unfair to point directly at the P2s and reiterate that point?
     
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  7. Jamessquared

    Jamessquared Nat Pres stalwart

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    You could - I couldn't possibly comment ;)

    Tom
     
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  8. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    Thank you Tom! ;)

    I do think you have underlined though why the “tried to rid the LNER of Gresley” line that is often pervaded really isn’t the case at a practical level.
     
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  9. jnc

    jnc Part of the furniture

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    Thanks; very interesting.

    Two minor things; a point you could make, and a wording suggestion:

    - P2 class showing up as the worst of the Gresley classes with poorer overall availability from their inception in the 1930s - i.e. starting before the 'poor maintenance' period caused by the loss of staff.

    - where the writer decries Thompson, they often forget - might be better as 'the writers decry Thompson', both i) to agree with the plural in the rest of the sentence, and ii) "the writer" might be initially mistaken to refer to you, whereas the plural is unambiguous.

    Noel
     
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  10. bluetrain

    bluetrain Member

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    S.A.C. Martin said:

    "It was very significant that in the case of the D.49 class the distortion was of such magnitude as to warrant the abandonment of the poppet valve."


    Simon - Is it the D49/3 oscillating-cam sub-class that is being referenced here? Or have I misunderstood?

    Just out of background interest, do the availability statistics indicate any difference between D49/1 piston-valve and D49/2 rotary-cam sub-classes?
     
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  11. bluetrain

    bluetrain Member

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    Hamilton Ellis aired the thought that, had Stroudley lived longer, maybe the path forward from the Singles and Gladstones would have been a 2-4-2 express engine. Such machines were apparently called "Columbia types" in the USA. They also became popular south of Paris on the PO and PLM railways, but had evolved there from 2-4-0 long-boiler engines.

    (EDIT: The only British 2-4-2s were the LNWR "Greater Britain" and "John Hick" classes - in which Mr Webb omitted the coupling rods).

    Interesting that James Stirling was a major builder of 0-4-2 mixed traffic engines in Scotland, but dropped that design on moving to the SER. Patrick Stirling on the GNR built the largest number (154) of 0-4-2s in England, but Ivatt and Gresley had scrapped the lot by 1921.

    In the later 19th and early 20th centuries, all of the major SR constituents practiced standardization up to a point, but perhaps more on the SER and SECR than on the others. I do wonder whether James Stirling could be given the accolade as Britain's most ardent practitioner of loco standardisation. When he left office, 3 types (F-class 4-4-0, O-class 0-6-0, Q-class 0-4-4T) made up 70% of the SER loco stock. Could any other major railway match that?
     
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  12. Jamessquared

    Jamessquared Nat Pres stalwart

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    In that light though, Bradley notes:

    "It has been suggested that Stroudley, fully appreciating the 'Gladstone' limitations, had a large express 2-4-2 tender class on the design board at his death, although this cannot be confirmed. All other Craven and Stroudley engines, both proposed and built, were preserved in drawing portfolios, and the 2-4-2may well have been another Brighton myth. " [i.e. the inference being that not only is the drawing missing, but if the proposal was genuine, that is anomalous in that all other such proposed classes had their drawings preserved.] Bradley later mentions "No drawings or other details have ever come to light of a Stroudley 2-4-2 tank replacement of the D1's."
    I do wonder how you develop an 0-4-2 logically into a 2-4-2, since the whole relationship of cylinders / front axle / smokebox would seem to be different.

    In that light, Wainwright continued the policy, constructing 287 locos to his own design (*) of which 79% (226 locos) were from just three classes: class D 4-4-0; class H 0-4-4T or class C 0-6-0.

    (*) Including the 22 L class 4-4-0s which were delivered after he left office.

    Tom
     
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  13. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    My understanding is that yes, it is.

    I will see if they’re split like that but unlikely I’d say.
     
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  14. 60525

    60525 New Member

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    Very interesting read @S.A.C. Martin . Thank you for sharing it. One question from me:- What happened to Bert Spencer when he was moved from his technical assistant role? I haven't seen it recorded anywhere, although I understand he returned to the role or something similar when Pepp took over in 1946.
     
  15. 8126

    8126 Member

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    A 2-4-2 would be an odd tender engine arrangement to go with, it seems a bit like wishful thinking along the lines of "Of course the great man would do something different!" My understanding has always been that Stroudley's preference for the 0-4-2 was justified by trying to keep his classes short, to avoid stretching the capacity of sheds and other facilities. Adams developed the mixed traffic 0-4-2 Jubilees for similar reasons, building a more powerful engine within weight constraints (for which length can be a proxy). Especially with the relatively short fireboxes of early examples, I find it extremely hard to believe that a 2-4-2 would actually be usefully lighter and shorter than a 4-4-0 for a given duty.

    That said, no Stroudley engine ever did have a bogie, even if by 1889 Adams (and, whisper it, Drummond, among others) was busy proving the virtues of 4-4-0s elsewhere, so maybe a 2-4-2 would have been more in keeping with his design traditions.
     
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  16. bluetrain

    bluetrain Member

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    Tom - Thanks very much for your thoughts and most interesting graph of the SR constituents' loco position in the mid-Victorian period. Loco design seemed to settle down in the 1870s, with coal-burning firebox having been sorted-out, the inside-cylinder 4-4-0 emerging and the inside-cylinder 0-6-0 cementing its dominance of the freight scene. Engine size and configuration seemed to evolve only marginally over the 1875-1895 period, albeit with the important invisible change of steel replacing wrought iron (allowing higher boiler pressures etc), arrival of continuous brakes and belated attention to crew welfare (cab roofs of sorts, more handrails, etc).

    Moving forward to the SR of 1923, it acquired some very ancient locos in IoW, almost as old at the time as the Class 483s today. But on the mainland, the principal SR constituents look to have maintained similar patterns of engine longevity - a substantial number post-1900, most of the rest post-1880 and just small numbers of mid-1870s survivors from the LSWR, LBSC & LCDR.

    But moving on to the LMS & LNER constituents, the picture becomes a little more varied. Some lines, such as the Great Eastern and Lancashire & Yorkshire, appear at Grouping to have had almost nothing more than 40 years old. The Scottish lines, except for the Caledonian, had more than their fair share of elderly locos. Post #3552 suggests that Ireland was in a similar situation. But among the major companies, it is the Midland that stands out for having a very large number of very old engines at Grouping, with 20% of the fleet (600 out of 3000) more than 50 years old, dating from the Matthew Kirtley period that had ended in 1873. Most of these veterans were Kirtley double-frame 0-6-0 goods . They had doubtless been through multiple changes of boilers and cylinders, as well as picking up cab roofs and vacuum brakes, but presumably still contained some original metal. Their survival is likely linked to the Midland "small engine policy" and its enthusiasm for double-heading.

    Drifting a little back towards the main topic of this thread, the LNER position is that the Southern Area (GN/GC/GE) engines were nearly all post-1880, but the NER still had many 1870s-vintage 0-6-0s (398 class). The NBR was the only LNER area where Gresley had to take early action to replace a large number of over-age engines. But as all the inherited engines aged after 1923, LNER loco construction stalled due to the recession, just at the time when a Thompson-like standardization and replacement programme became desirable.

    Most post-Grouping builds had their lives cut short by dieselisation, while the LMS "scrap and build" policy will skew any quantitative assessment of the longevity of LMS constituent engines. There have of course been other more limited examples of locos being scrapped early due to policy decisions, such as the ones that Maunsell withdrew following Southern electrification. One interesting case concerns the LMS Fowler 7F 0-8-0, of which 175 were built in 1929-32, largely replacing L&Y 0-8-0s built 1900-20. In 1949, BR decided to partly use the influx of WD 2-8-0s to replace the Fowler 0-8-0, most of which were themselves scrapped in the early 1950s.

    Finally, Mr Drummond's four-cylinder follies were too few in number to greatly affect any overall statistical analysis of his work. But I notice that the Rebuilt F13s were still around to create hard work for firemen in the 1950s. If one of those had made it to Mr Woodham's establishment ...............
     
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  17. jma1009

    jma1009 Well-Known Member

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    I am grateful for Simon in posting on here his chapter on Bert Spencer.

    I don't myself consider that Bert Spencer was an advocate of conjugated gear at all, as his paper quoted by Simon supports. In fact Bert Spencer was quite critical of the conjugated gear, and it was he who provided Cox/Stanier with the data and evaluation that the Cox/Stanier report was based upon.

    My point is that Thompson got rid of Spencer, who without any doubt was the leading expert on valve gears on the LNER. Not quite up to the understanding that Holcroft and W H Pearce had on these matters, and also Sam Ell at the time.

    The idea that Thom should suggest equal con rod lengths is simply fanciful, as unequal length con rod lengths can easily be dealt with by the experts.

    That Thompson was taken in by this argument shows his own failure to grasp the niceties of valve gear design. Gresley was just as much at fault in understanding valve gear design. Maunsell and Bulleid also failed to understand the niceties of valve gear design.

    To relegate Bert Spencer away from Doncaster by Thompson, and to effectively dispense with the services of the LNER's valve gear expert is not easily explained away.

    As to the hearsay comments of Spencer on the Great Northern, these ought to dealt with face on and in detail in what is supposed to be a seminal work of research.

    Cheers,
    Julian
     
  18. Jamessquared

    Jamessquared Nat Pres stalwart

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    Perhaps the fact that Gresley, Maunsell, Bulleid and - whisper it - Thompson all made successful locos that did a remunerative job for their companies despite, in your words, “failing to understand the niceties of valve gear design” shows that they had a more rounded view of what was necessary than you seem to? There is more to sound locomotive practice than just getting nice valve events: in your monomania about Spencer, you seem to be completely ignoring the significant argument that the LNER’s problem in the 1940s wasn’t the existence of some dodgy looking indicator diagrams. Their fundamental problem was loco availability. You need a management team well versed in workshop and shed practice to sort that one out, not a valve gear expert.

    Tom
     
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  19. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    You are welcome, Julian.

    There's a couple of things at work here though Julian.

    • Spencer was absolutely pro-conjugated valve gear. That is a matter of public record. He was tasked with improving it by Gresley in the late 30s/early 40s, along with Thompson.
    • He disagreed with Thompson's approach to locomotive design policy on the LNER.
    • Thompson is quite at liberty to change the makeup of his team to suit his needs and requirements.

    This too, is a matter of public record. Robert Thom became one of Thompson's assistants and he suggested equal length connecting rods. Many railways have employed equal length connecting rods on their locomotives - notably the GWR and LMS did so with their largest locomotives (Castle, King, Princess). This is not "wrong" but it is "different" to the three cylinder practice on the LNER.

    This, plainly, is not true. There is absolutely nothing wrong with the theory of divided drive, and equal length connecting rods, and - point of information - there was absolutely nothing wrong with the Thompson front end if you look at the engine cards, and what was actually being repaired on the Thompson Pacifics (as I have done, across all of them).

    It is significant and notable that the Thompson Pacifics throughout their lives did not suffer crank axle failure, nor valve gear failure of the type that the Gresley Pacifics suffered throughout their working lives.

    So far as actual maintenance and repair work being done to the Thompson Pacifics is concerned, divided drive and three sets of valve gear with equal length connecting rods (Great Northern exempted), was an absolute success story. Because the argument isn't about the choice of valve gear so much as it is about locomotive availability. One of the biggest eye openers in the whole of my time researching Thompson and the work done under him is how quickly his Pacifics came into service, and how well out of the box they worked.

    Many LNER writers have written on their trips to works and interpreted the numeracy of going to works as "failure" when in fact the opposite is true, when you look at it from the largely correct point of view, that you need to maximize the number of locomotives available for work at any one time. In this, the Thompson designed locomotives - not just the Pacifics - were a great success. I say that on the basis that I have been collating the statistics, as you know, for nearly two years on LNER locomotive availability.

    No one man is more important than the railway and getting the job done. There's a line of thinking which states that the C.M.E. should always have to justify his choices in personnel.

    As far as I can see, you could (but I emphasize, I personally have no wish to) lay the locomotive availability failures directly at Spencer's door, given he is, as you say, the LNER valve gear expert and the poor locomotive availability on the LNER was happening on his watch.

    Therefore you could feel that Thompson was correct in removing Spencer and putting Robert Thom in the setup in his stead - because the basic statistics that we have show that all of the major L.N.E.R. classes after 1942 were improving in availability across the board, with changes Thompson made to maintenance policies (which I go into in a separate chapter) together with changing the nature of LNER locomotive design from 1942 onwards.

    If your star striker has not scored for a 100 games, do you play him for the 101st game?

    It goes both ways Julian, does it not?

    I felt I made my views clear in the Spencer chapter and on that I feel the matter is now closed.

    Julian, it is really difficult to take your views seriously when you constantly talk down my work. I have - I like to think anyway - gone above and beyond in making material, evidence, and more available to everyone who takes part in this discussion. We have gone further in discussing the economics and practicalities of locomotive design on the L.N.E.R. in so many ways, including looking specifically at their own statistics and then between us all, devising a way to actually measure their performances over many years.

    It is - I am happy to admit - quite hurtful that you talk down my work every time you come on this thread, given the efforts I have made to accommodate everyone as much as possible. I am not obliged to give out any of my research: I do so freely because I believe in what I am doing and I do not see the point of keeping any of it hidden from discussion.

    Tom - as always - summing it up far more concisely than I am able! Thank you.

    Everyone - thanks again for all of your thoughts. The off-topic discussion has been really interesting of late too - I want to emphasise that I have not minded that discussion in the slightest, as it helps to cement a few ideas and shows consistency in approach is invaluable.

    Merry Christmas, and a happy new year.
     
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  20. jma1009

    jma1009 Well-Known Member

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    Hi Simon,

    You will have to substantiate this remark, because Spencer's paper that you quote, and the data he supplied to ES Cox for his report that you also significantly published, makes it quite clear Spencer was quite aware of the deficiencies of 'conjugated gear' as used by Gresley.

    One of the reasons that I have banged on about Spencer is that he actually supports most of your views!


    I take some exception to this, 'Jamessquared', as this states/or at the very least implies I have some psychosis or mental illness, and I would ask you to please re-consider your post 3578 and edit it.

    The obvious example is the LNER A1s as originally built by Gresley with short travel short lap valves, against Spencer's advice, and which the interchange trials with the GWR Castles showed up significantly. That is not "monomania" on my part; and I would consider the subsequent alteration of the A1s to long travel long lap valves as advocated by Spencer shows that Gresley misunderstood valve gear design, in exactly the same way he could not fathom how to have an inclined middle cylinder with 'conjugated gear' until Holcroft showed him how this could be easily achieved.

    Cheers,

    Julian
     

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