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Steam speed records including City of Truro and Mallard

本贴由 Courier2011-01-30 发布. 版块名称: Steam Traction

  1. simon

    simon Resident of Nat Pres

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    Sayre's law states, in a formulation quoted by Charles Philip Issawi: "In any dispute the intensity of feeling is inversely proportional to the value of the issues at stake."
     
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  2. Jon Lever

    Jon Lever New Member

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    Yes, which is why most university arts faculties are riven with ill-feeling and vituperous behaviour sooner or later, often on a recurring basis. As W.B Yeats put it, "The best lack all conviction/While the worst are full of passionate intensity"
     
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  3. bluetrain

    bluetrain Well-Known Member

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    So the fiercest arguments among rail enthusiasts will be ..... livery debates.
     
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  4. Jimc

    Jimc Part of the furniture

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    Quod erat demonstrandum...
     
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  5. Hermod

    Hermod Well-Known Member

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    [​IMG]
    Not so important as liveries but a probable explanation on the record.
    Please enlarge this picture and look at the paper drum brass-rim.
    There are four ramps that most likely make the quarter mile marks.
    Different drag on each ramp or not quite 90 degree apart and the blue speed curve is nondata.
    The red 1938 LNER curve is based on same data,but molested further.
    One mile cyclic disturbance is still waiting for explanation.
     
    Last edited: 2023-12-20
  6. MellishR

    MellishR Resident of Nat Pres Friend

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    If the movement of the paper is slightly delayed each quarter mile, that should not matter. There is a still a mark on the paper showing that the train has travelled a quarter mile, and the time trace records how many seconds that has taken.
     
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  7. Hermod

    Hermod Well-Known Member

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    The blue curve speeds imply that Mallard, at some points,puts in more than 3000 indicated horsepower extra during 3.5 second long bursts.
    Using a 5 second filter on same data (and selecting the most suitable as rekord (Red curve) ) it will need extra power bursts ,very skillfully timed, of ca 700 ihp from a basicly 2200 ihp hard working locomotive.
    Only one mile average speeds can be extracted from roll with a precission of mr Andrews 1:2000 for distance and thrustworthyness of chronometer in vibrating environment.
     
    Last edited: 2023-12-20
  8. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    So, checking my data, I have been experimenting with putting together the formula for working out DBHP in excel alongside the “known” DBHP data we have noted on the dynamometer roll.

    The highest DBHP I can see on the roll is 1800 at “96 milepost” and 116mph recorded. Mallard’s DBHP goes down as she approaches the 125/126mph mark after climbing to 1800 over the trip to that point.

    When sorting out my quarter mile data it will be a relatively straightforward job to calculate that for each quarter mile, so again we will have more plot points to examine and consider.
     
  9. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    I disagree with both of these comments, though I understand they are made with good intentions.

    On the contrary, I think the state of the world shows today that the greatest issues have very intense feelings from all sides. Whether they are deserved is another matter.

    On the subject of conviction, I think having passion and conviction is entirely possible, and a dispassionate logical analysis is usually preferred. I think passion comes into it through miscommunication, which is rife in so many debates.
     
  10. Jon Lever

    Jon Lever New Member

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    Simon, indulge me just this once, and go back and re-read what I said. In context here, I specifically applied Sayre's law (by quoting a previous post) to the sort of childish behaviour that frequently occurs in departments where a festering grudge can built on nothing more than who got the last biscuit at elevenses in the SCR. At its most extreme it leads to vendettas such as that which embroiled Martyn Percy at Christ Church. These arguments are almost always entirely personal and tend to have no grounding in any philosophical or academic disagreement.

    I agree that it is possible to have both passion and conviction, but I think the balance in what Yeats says (personal interpretation only) is that the best lack conviction because they are aware of the nuances which preclude the use of absolutes unless unambiguously shown or proven. The worst, on the other hand, represent the embodiment of a quote (which I am unable to attribute) 'for every difficult and complex question, there is a simple answer. Which is wrong'.

    TL;DR more angels, more pinheads, less signal, more noise
     
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  11. Hermod

    Hermod Well-Known Member

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    It is higher than a Britania.Is it a handwritten number?
     
    Last edited: 2023-12-20
  12. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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  13. Allegheny

    Allegheny Member

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    This is probably a red-herring, but there can be an effect when dealing with sampled data known as "aliasing".
    Among other things it occasionally makes wagon wheels look as if they are rotating backwards on old cowboy films, due to the interaction between the camera frame speed and the rotation of the wheel. If you're doing a PhD., it's probably worth checking out, and probably eliminating.
     
  14. simon

    simon Resident of Nat Pres

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    You are free to disagree with it, however I would contend that life is full of examples. one only had to read some of the threads on here to see how people can react to minor issues, disagreements,over things,that dont matter of which they cannot influence, or perceived slights.


    There are of course issues of great intensity in the world and people have serious disputes and conflicts over these, but that is a different point.
     
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  15. Hermod

    Hermod Well-Known Member

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    If the quartermile cyclic error theory holds water, four successive roll sections ( close to 150mm long each) ,between quarter mile marks will vary roughly 2mm in length.
    Original roll,from MP 93 to MP89.75 where the action was.
    About time for a quality scan?
    Whitout scan, quality photo can evaluate quarter mile marks calibration 86 years later.
    A lens transfered copy can hardly hide a 2 on 150mm differences .
    If this test strategy has already been mentioned and results evaluated,I have missed it .
     
    Last edited: 2023-12-22
  16. Maunsell907

    Maunsell907 Member

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    Mr Andrews has asked me to post the following on National Preservation.

    David wishes this to be simply a statement of his opinions. He does not wish
    to enter into any dialogue on NP.

    I have endeavoured to copy within the limits of my octogenarian IT abilities

    Michael Rowe

    DB543F26-A9C8-4927-85F8-58AAE098568E.png 62F0B20D-8EA9-4F16-ABD2-7308F4351A03.png
    22D93D60-8B33-4C39-9EFF-DBCC48676429.png 浏览附件81572 浏览附件81571 浏览附件81572
     
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  17. Kylchap

    Kylchap Member

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    Thanks for sharing this with us.
     
  18. Hermod

    Hermod Well-Known Member

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    If mr Andrews claim of Mallards superior power is based on 1938 roll results from DynoWaggonYork it deserves further investigation.
    I will happily supply results from my cheap power model when I get the Gottwaldt book.

    The thread subject is dubious speed claims and why?
    Clowns or Crooks?
     
    Last edited: 2023-12-23
  19. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    I think I will have to reach out to him directly then, as I have new questions arising from the above.

    Thanks for sharing this Michael, very interesting.
     
  20. Hermod

    Hermod Well-Known Member

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    When returning from a nice walk with dog in the woods my Gottwaldt book was on my dorstep.
    Stay tuned for a free X-Mas gift
     
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