If you register, you can do a lot more. And become an active part of our growing community. You'll have access to hidden forums, and enjoy the ability of replying and starting conversations.

Ton up Tornado

Discussion in 'Steam Traction' started by MarkinDurham, Apr 12, 2017.

  1. Nick Gough

    Nick Gough Well-Known Member

    Joined:
    Feb 4, 2006
    Messages:
    1,433
    Likes Received:
    340
    Location:
    Northamptonshire
    So when is Tornado going to have a go at City of Truro's record?;)
     
  2. MellishR

    MellishR Resident of Nat Pres Friend

    Joined:
    Apr 16, 2009
    Messages:
    8,068
    Likes Received:
    5,165
    Hasn't it just done so? Round about 100 mph, probably a tad over, on fairly level track whereas CoT's was down the bank from Wellington.

    Edit. BTW I suggest all these posts here about Tornado be moved to the Ton up Tornado thread.
     
  3. henrywinskill

    henrywinskill Well-Known Member

    Joined:
    Nov 3, 2005
    Messages:
    2,245
    Likes Received:
    3,537
    Occupation:
    Transgender toilet attendant
    Location:
    North East
    Heritage Railway Volunteer:
    No I do not currently volunteer
     
  4. Sean Emmett

    Sean Emmett Member

    Joined:
    Sep 7, 2014
    Messages:
    578
    Likes Received:
    489
    Gender:
    Male
    Location:
    Bristol
    Very sensible! Remember City of Truro's claimed precise 102.3 mph was based on 8 4/5 sec for quarter mile on a stopwatch that only recorded to nearest 1/5 sec!

    Agree re gps - I set my gps to record a track log every second, for analysis later. Very useful for the Bittern 90 mph trips. On the final Newcastle to York run I recorded a consistent 95 max for 7 seconds, but not for full 10 sec i.e. quarter mile.
     
  5. 8126

    8126 Member

    Joined:
    Mar 17, 2014
    Messages:
    823
    Likes Received:
    962
    Gender:
    Male
    Some interesting points in the thread so far.

    I agree that any of the preserved Class 8 locos could do the same as Tornado just has. A fair few of the Class 7 types as well, but it's not so cut and dried and for a couple of them Network Rail might start to take a dim view of the hammer blow. Which leads me neatly onto my next point that, Tornado apart, these are all old ladies and 90mph puts the dynamic forces alone up by 44% compared to 75mph. That sort of increase in force can easily be the difference between fatigue cracks progressing or not - it's not that the parts are in bad condition on the older engines, they've just got less of their life left.

    Even Clan Line, a relative baby in the Class 8 club, was withdrawn with about 800k miles on the clock and needed some weld repairs to the frame stretchers during her current overhaul, having done a fair few miles since 1967. So yes, they can all do it, but for those that do there will be an ongoing increase in costs if they repeatedly run at 90 for extended periods. Clearly the A1 group have decided that the opportunities it opens up outweigh those costs. Other groups will make their own choices; there are good arguments either way.

    Finally, did anyone else notice the crew commenting that it was "A bit rocky, swinging around a bit," (paraphrased) in the BBC report. Clearly the A1 tendency towards lively riding at speed is something Tornado shares with her forebears. ;)
     
  6. paullad1984

    paullad1984 Member

    Joined:
    Oct 16, 2007
    Messages:
    918
    Likes Received:
    428
    But wasn't the bad riding cured by trying an A4 bogie back in br days?
     
  7. RobHickerton

    RobHickerton New Member

    Joined:
    Jul 18, 2006
    Messages:
    175
    Likes Received:
    159
    Occupation:
    Engieering Consultant
    Location:
    Wiltshire
    Measuring anything to better than within 5% is very difficult. A lesson I learnt from my Physics teacher about 60 years ago, and its still true. Speed requires measurement of distance and time, so if you get within 5mph at 100 thats pretty good. Frankly 0.6 of an mph is delusiory.

    Rob
     
  8. Spamcan81

    Spamcan81 Nat Pres stalwart

    Joined:
    Aug 25, 2007
    Messages:
    35,121
    Likes Received:
    20,773
    Occupation:
    Training moles
    Location:
    The back of beyond
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    You mean slow down to just under the ton? ;)
     
    weltrol and 60017 like this.
  9. pmh_74

    pmh_74 Well-Known Member

    Joined:
    Jan 28, 2009
    Messages:
    2,217
    Likes Received:
    1,456
    To do that surely someone needs to pop Tornado in a time machine first.
     
  10. S.A.C. Martin

    S.A.C. Martin Part of the furniture

    Joined:
    Aug 31, 2010
    Messages:
    5,591
    Likes Received:
    9,325
    Gender:
    Male
    Occupation:
    Asset Engineer (Signalling), MNLPS Treasurer
    Location:
    London
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Yes and no. This was as far as I am aware only applied to one Peppercorn A1 - and it was returned to its original format at some point. It is interesting to note that the best riding Pacifics remained the A4s on the LNER and almost all other classes suffer with some level of stories as to their bad riding.

    The Peppercorn A1s seem to have suffered particularly badly - but one wonders if this was more about the length of time between classified repairs. Understandably a locomotive doing longer mileage between repairs may become a bad runner of sorts.
     
    paullad1984 likes this.
  11. MellishR

    MellishR Resident of Nat Pres Friend

    Joined:
    Apr 16, 2009
    Messages:
    8,068
    Likes Received:
    5,165
    Considering the immense increase in knowledge about rail vehicle dynamics since the A1s were designed, and the work that the Trust did on that subject before starting to build the P2, there ought to be some scope for improving Tornado's behaviour at speed.
     
  12. acorb

    acorb Part of the furniture

    Joined:
    Jul 17, 2007
    Messages:
    2,505
    Likes Received:
    3,247
    Location:
    Powys
    I would think any steam locomotive might be a bit bumpy at 100mph+?!
     
    Martin Perry likes this.
  13. class8mikado

    class8mikado Part of the furniture

    Joined:
    Jun 1, 2009
    Messages:
    3,610
    Likes Received:
    1,438
    Occupation:
    Print Estimator/ Repository of Useless Informatio.
    Location:
    Bingley W.Yorks.
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Tornado already has the Cartazzi designed for the A4, not the one on the PcA1 drawings ( which is probably the same as the P2, A3..) .and I believe its bogie control settings are on the stiff side for a Pc A1 also
    but as acorb says ....
     
  14. Nick Gough

    Nick Gough Well-Known Member

    Joined:
    Feb 4, 2006
    Messages:
    1,433
    Likes Received:
    340
    Location:
    Northamptonshire
    Only on the uphill bit.
     
  15. Matt37401

    Matt37401 Nat Pres stalwart

    Joined:
    Jun 8, 2014
    Messages:
    15,328
    Likes Received:
    11,666
    Occupation:
    Nosy aren’t you?
    Location:
    Nowhere
    Heritage Railway Volunteer:
    No I do not currently volunteer
    As regards class 50's I recall the 50 Alliance gave instructions for them to be allowed to coast at 90mph, But were given a 75mph under power restriction. This is something Laira depot did to reduce Flashover risk, during the 50 Railtour years 92-94
     
  16. Big Al

    Big Al Nat Pres stalwart Staff Member Moderator

    Joined:
    May 30, 2009
    Messages:
    21,065
    Likes Received:
    20,773
    Location:
    1016
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Not necessarily. Please don't let's digress too much but when 35023 touched 102 on the approach to Andover in 1966, the legendary Bert Hooker who was driving it at the time said that the faster the engine went the more smoothly she rode. Different locos have different ride characteristics. There is, of course, the track they are on.
     
  17. 8126

    8126 Member

    Joined:
    Mar 17, 2014
    Messages:
    823
    Likes Received:
    962
    Gender:
    Male
    I thought the A3s didn't have too bad a reputation either. Mind you, they came after the Ivatt Atlantics, which according to many gave a truly wild ride. From Townend, I believe the A1s could be quite unnerving straight out of shops, although beefing up the side control springs supposedly helped.

    If I was going to dig out my long-neglected vehicle dynamics modelling and extrapolate it to rail vehicles, I'd guess that the LNER bogie and Cartazzi combination was good enough for the A4s, but not quite the master of the A1s, with the middle cylinder out ahead of the bogie pivot and a heavier firebox above the trailing truck, especially if the side control settings were left much the same. If you look at the mass distribution of the two classes, the A4 looks like a slightly better vehicle - less of it out at the extremities, so it doesn't take as much force to guide it and there's less energy to dissipate if it starts a yaw oscillation.

    Of course, the Duchesses, with two inside cylinders in much the same place as the A1, had an excellent reputation for their quality of ride (including a well known precipitous entry into Crewe), but then they had a different trailing truck, and the well-regarded De Glehn-by-way-of-GWR bogie.
     
  18. pete2hogs

    pete2hogs Member

    Joined:
    Oct 16, 2007
    Messages:
    721
    Likes Received:
    418
    IIRC it was never disclosed at the time exactly what was done to steady up the A1's but something was done. It wasn't the A4 bogie. I seem to remember someone saying from a Works perspective that the ride wasn't considered dangerous, so the modification was made in normal works visits and they didn't want all the A1's sent back for it at once. I don't have time to search for the reference at the moment. If I trust to memory I think it was something like the side forces had not been recalculated since the bogie was designed for the B1's and the cure was to adjust the side control allowing for the heavier loco with greater overhang. There was also the miscalculation of the Cartazzi slides. One gets the impressionm that the difficulties between the Drawing Office and Management (to name no names!) had resulted in some lack of joined up thinking in detail design.
     
  19. Hirn

    Hirn Member

    Joined:
    Aug 11, 2015
    Messages:
    462
    Likes Received:
    295
    Gender:
    Male
    I can't put my hands on the exact reference either but it was a much higher loading on the side control springs
    for the bogie. Which was discreetly done in the works and not at all mentioned at the time.
     
  20. gricerdon

    gricerdon Guest

    Maybe because it was being worked at full regulator and 45% cut off?
     

Share This Page