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Saint Class 135 ish mph

Discussion in 'Steam Traction' started by Reading General, May 5, 2017.

  1. Hermod

    Hermod Member

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    A Danish IC 3 train is 60 meter long and is 100 tons and use 1600 horsepower to go 180 kmh.A 100 tons A4 plus 3 cars are longer (80m?) and not so smooth.
    Horsepower to go 200kmh must have been at least 2200 horsepower.A Britannia at same rev per second had 1500 hp and grate area/tube cross section was comparable.
    Accelerating to 201.5kmh in 400 m is good engineering inded.
    A 135 mph two cylinder Saint is just much better good engineering.
     
  2. Spamcan81

    Spamcan81 Nat Pres stalwart

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    Backing him all the way.
     
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  3. Courier

    Courier New Member

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    For Mallard we have the speed curves drawn by the LNER (which show odd fluctuations in speed with an odd peak at 125-126mph. Luckily we also have the dyno roll - and that shows a lower speed. For FS and Papyrus we have speed curves - which also show odd fluctuations. We do not have the dyno roll but it is fair to assume that the same errors apply and the true speeds were slightly lower than claimed.

    The difference between the LNER curve and reality is due to a combination of factors, each one small but all adding up. One of which was the fact that while the paper was travelling at 24" to the mile it did not do so at an even rate. It sped up and slowed down every mile causing artificial peaks and troughs in the speed.

    For Truro you can see the original data. Yes, the method was less accurate, but you can take that into account when assessing the data. For FS the original data has been lost and it is very hard to make sense of the second hand information that is left.
     
  4. Courier

    Courier New Member

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    Of course you might prefer the opinion of Darlington Testing and Performance Section given to the NRM in 1964. Regarding the 126 mph speed they stated....

    But this can only be an answer to railway enthusiasts... it would not stand up to a technical inquiry.
     
  5. paulhitch

    paulhitch Guest

    This is all football supporters "my team is better than your team" stuff. :rolleyes:

    PH
     
  6. Hermod

    Hermod Member

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    Are the Mallard Dyno rolls visible on web (free for all to see)?

    How long and heavy was City of Truro train and how steep the hill?
     
  7. Courier

    Courier New Member

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    - No.

    - The train (not including engine and tender) was circa 90 tons tare and 115 tons gross. The gradient varied from 1:127 to 1:80.
     
  8. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    All of which has been addressed and using the same +/- % methods other enthusiasts and mathematicians have applied, have shown that Papyrus at the very least achieved over 100mph and Scotsman was more than likely around 100mph. Both of which far more likely than CoT's record.

    Let me stop you there. So Truro's initial method is less accurate, but you can take that into account, whereas Scotsman's and Papyrus' was originally more accurately recorded and yet their records are somehow in doubt?

    Why introduce a new source if you are not going to quote their findings?

    To some extent, yes. It is also a case of I cannot believe that the dynamometer car is more inaccurate than the human eye, human reaction, a stopwatch and sight of a mile post at speed.
     
    Last edited: Oct 14, 2017
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  9. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    Quite frankly I think the likelihood of there ever having been a 135mph Saint to be as likely as my Volvo reaching the moon.
     
  10. Hermod

    Hermod Member

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    Volvo is chineese these days and they are next on moon(If the indians do not beat them).
     
  11. Hermod

    Hermod Member

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    Another source says 90 tons for locomotive so we have 205 tons going down with 0.45 meter per second on a 1:100 incline with 100 mph.
    This is 905 kW gravity assist.
    Same source says 5 postal boggie vans.Is total train length 100 meter realistic?
     
  12. Copper-capped

    Copper-capped Part of the furniture

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    Good fun to have a bun fight where no one gets hurt isn't it! I do so love it when this thread gets bumped :D
     
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  13. Matt37401

    Matt37401 Nat Pres stalwart

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    Easy money :)
     
  14. andrewshimmin

    andrewshimmin Well-Known Member

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    I'm afraid it doesn't matter what data re-analysis (to use a polite version) anyone does.
    These locos are or aren't record breakers because their records were or weren't accepted at the time. Some of them (CoT) were half-accepted and so they are partial or disputed record-breakers.
    The reputational/sociological factor is far more important than the technical at this remove.
    Besides, if people were using the best available data/analysis techniques on hand on the day, that's that. Re-analysis on the basis of partial information and gross mechanics and dynamics assumptions applied to a highly complex problem is little short of guesswork.
    If anyone is claiming anyone else falsified data, but wasn't picked up at the time, they're just spreading damaging insinuation about the long dead.
    As an LMS partisan, personally I never really believed the LMS record, but it's a nice thought. The LNER records look solid to me (and the German one of course). I don't care which was actually better, they were both jolly fast.
    I would happily accept CoT also, since the legend saved the loco. So long as we also accept it's not proved beyond reasonable doubt.
    The Saint claim is clearly bunkum.
     
  15. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    This seems fair to me. :)
     
  16. Reading General

    Reading General Part of the furniture

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    yes the bad news is the Chinese are going to the Moon, the good news is....all of them...

    old non PC joke.
     
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  17. Jimc

    Jimc Part of the furniture

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    Its all about quality of measurement. As I've said before most of the steam records would laughed off the stage in any other context, since they have a large component from gravity on banks, and there's no doubt the LNER had the best hill. Typically though to be accepted as a record the measurement needs to be close to the limits available at the time.

    If you look at COT it was measured to the limits available at the time, and was without doubt the record speed measured on rail at that time. However the limitations of the measurements available and the fact that she was braked part way down the hill mean that what we know is that the locomotive was travelling at at least 99mph and almost certainly over 100mph - and apparently still accelerating. A genuine record, but if there had been an independent records body at the time they would probably only (!only!) have accepted 99mph as being proved.

    If you look at the Saint exploit, it wasn't measured in any structured way, and is in no way fit to be described as a record, but it seems likely they were travelling at well in excess of 100mph, quite possibly in the vague region of 120mph. No-one would even have bothered to submit the incident to a records body had there been one.

    When we get to the LNER dynanometer trace based records, you have a much better technology, and so greater accuracy. But had there been an independent records committee they'd probably have insisted on the low figures - as did Gresley for Mallard AIUI - 125 rather than 126.
     
    Last edited: Oct 15, 2017
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  18. Eightpot

    Eightpot Resident of Nat Pres Friend

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    Putting it into reverse gear and opening the regulator, so beloved of film makers! However the plain fact is that with the driving wheels spinning the opposite direction to the travel they are not gripping the rails , thus not contributing anything to stopping the loco or train.
     
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  19. Spamcan81

    Spamcan81 Nat Pres stalwart

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    I can vouch for that. Was on a runaway train on the Paton Country Railway in Natal. In an attempt to retard the train the driver put the NGG11 into reverse. Quite spectacular but did sweet f.a. to slow things down.
     
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  20. andrewshimmin

    andrewshimmin Well-Known Member

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    Presumably throwing a GWR loco into reverse is a risky business given the lever reverser? On other railways I have heard of faulty lever reversers jumping and throwing men on the floor, off the footplate, or pinning them to the boiler... Not nice.
     

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