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.

71000 Matters

Discussion in 'Steam Traction' started by paralaxerror, Jan 12, 2013.

  1. Jamessquared

    Jamessquared Nat Pres stalwart

    Joined:
    Mar 8, 2008
    Messages:
    16,009
    Likes Received:
    22,772
    Location:
    21C102
    Surely not? You just allow for the relevant mechanical advantage: for example, if you have a 2:1 gear that means you need twice as many piston strokes as normal per wheel revolution, then the TE is doubled (but the same number of piston strokes per minute means the speed is halved, so the power remains the same).

    Try working out the TE on this piece of Victoriana ...

    https://flic.kr/p/ehn9Sk

    Tom
     
    andrewshimmin likes this.
  2. 30854

    30854 Part of the furniture

    Joined:
    Mar 8, 2017
    Messages:
    3,437
    Likes Received:
    3,365
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Brighton&Hove
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Spoilsport! And where rack gear can be disengaged? ....

    Unfortunately, the link you provided comes back dead, though there have been some remarkable creations over the years which defy accurate classification, never mind a meaningful, yet always theoretical, TE calculation which in any case takes no account of real-world performance limiting factors from grate area to pinch-points in the steam circuit. For just one example, Lawson Billinton's semi-successful B4X demonstrated this rather too well.
     
  3. Jamessquared

    Jamessquared Nat Pres stalwart

    Joined:
    Mar 8, 2008
    Messages:
    16,009
    Likes Received:
    22,772
    Location:
    21C102
    Try this for this afternoon's homework :)

    [​IMG]

    Fell locomotive H199 by Tom James, on Flickr
     
    andrewshimmin likes this.
  4. 30854

    30854 Part of the furniture

    Joined:
    Mar 8, 2017
    Messages:
    3,437
    Likes Received:
    3,365
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Brighton&Hove
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Ooh...... Nice.! That's one o'them Middle Earth Govt Railway locos for the Rikki-Tikki-Tavi line innit?
     
    Last edited: May 31, 2018
    Jamessquared likes this.
  5. Steve

    Steve Part of the furniture Friend

    Joined:
    Oct 7, 2006
    Messages:
    9,112
    Likes Received:
    4,195
    Occupation:
    Gentleman of leisure, nowadays
    Location:
    Near Leeds
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    30854 likes this.
  6. Ploughman

    Ploughman Well-Known Member

    Joined:
    Apr 1, 2008
    Messages:
    4,004
    Likes Received:
    1,377
    Occupation:
    Ex a lot of things.
    Location:
    Near where the 3 Ridings meet
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Does it work with a Shay as well?
     
  7. Steve

    Steve Part of the furniture Friend

    Joined:
    Oct 7, 2006
    Messages:
    9,112
    Likes Received:
    4,195
    Occupation:
    Gentleman of leisure, nowadays
    Location:
    Near Leeds
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    If you know the gear ratio, yes.
     
  8. 30854

    30854 Part of the furniture

    Joined:
    Mar 8, 2017
    Messages:
    3,437
    Likes Received:
    3,365
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Brighton&Hove
    Heritage Railway Volunteer:
    No I do not currently volunteer
    ..... assuming the relevant components remained what was said on the box, back when they were delivered. A lot of Shays worked for yonks in some very out of the way places (even by American standards) where the remoteness of Lima's production plant made the IMR's Douglas workshops seem just a stone's throw from Gorton by comparison and therefore tended to be even more self-reliant and creative, to judge by the very few photos I've come across. :)
     
  9. thickmike

    thickmike New Member

    Joined:
    May 16, 2006
    Messages:
    221
    Likes Received:
    183
    Gender:
    Male
    Occupation:
    IT Consultant
    Location:
    Northants (near the GC bit)
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Anyone likely to write anything else about 71000??
     
  10. Richard Roper

    Richard Roper Member

    Joined:
    May 22, 2006
    Messages:
    540
    Likes Received:
    311
    Gender:
    Male
    Occupation:
    Librarian
    Location:
    Halifax, but almost in Sowerby Bridge
    Heritage Railway Volunteer:
    No I do not currently volunteer
    I'm wondering if the problem with 71000 having "dropped a beat" just before its withdrawal has been identified. I seem to remember at the time that the locomotive had been examined, and that nothing untoward had been found within the camboxes...

    Richard.
     
  11. class8mikado

    class8mikado Member

    Joined:
    Jun 1, 2009
    Messages:
    2,732
    Likes Received:
    845
    Occupation:
    Print Estimator/ Repository of Useless Informatio.
    Location:
    Bingley W.Yorks.
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Hmmm, nevertheless iirc some of the modifications to the valve gear made whilst in preservation are being reversed and components are to be replaced to the original 'BR' specification.
     
  12. MellishR

    MellishR Well-Known Member Friend

    Joined:
    Apr 16, 2009
    Messages:
    4,092
    Likes Received:
    1,821
    When they stripped things down they found that one valve had stuck. If all had been well with the finances it could have been put right fairly quickly.
     
    jnc and Richard Roper like this.
  13. MellishR

    MellishR Well-Known Member Friend

    Joined:
    Apr 16, 2009
    Messages:
    4,092
    Likes Received:
    1,821
    I think these are all comparatively minor tweaks, to try to improve performance slightly further or for practical reasons. The major changes from as-built condition in the first restoration were providing big enough holes in the ashpan to let enough air in and in the draughting, and those are certainly not going to be reversed.
     
    jnc likes this.
  14. 30854

    30854 Part of the furniture

    Joined:
    Mar 8, 2017
    Messages:
    3,437
    Likes Received:
    3,365
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Brighton&Hove
    Heritage Railway Volunteer:
    No I do not currently volunteer
    A bit of tweaking here and there is hardly surprising, after all 71000 was/is a prototype. Should anyone be rich/bonkers enough to build 71001 it'd be interesting to see what design changes were adopted in the light of experience. Possible answers may vary, according to how well the P2's 'breathed on' Lentz arrangement works out, among other innovations since 'The Duke' was built.
     
  15. class8mikado

    class8mikado Member

    Joined:
    Jun 1, 2009
    Messages:
    2,732
    Likes Received:
    845
    Occupation:
    Print Estimator/ Repository of Useless Informatio.
    Location:
    Bingley W.Yorks.
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Not sure the Lentz would work on 71000 for similar reasons that BR Caprotti would not work for the P2. The systems are very similar and I would expect any step forward to be in reliability rather than performance. A new build would Im sure be tempted to use three sets Walshaerts ( which has come on a bit since then) as less difficult/ less expensive, and dukeII would still be a serious machine. Makes you appreciate how brave the restorers were/ the P2 people are for going with this 'on the edge' tech.
     
  16. 30854

    30854 Part of the furniture

    Joined:
    Mar 8, 2017
    Messages:
    3,437
    Likes Received:
    3,365
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Brighton&Hove
    Heritage Railway Volunteer:
    No I do not currently volunteer
    I couldn't imagine you'd be talking about a 'straight swap' for a moment, though I'd be interested to know why no such redesign might be possible. Using three sets of Walschaerts is precisely the sort of regressive step I would not consider a 'USP' in any putative newbuild 71xxx. As attractive to many as Walschaerts gear undoubtedly is, what exactly would it prove? If that's the notion, one might as well just knock out* another 'Britannia' or, if that's not sufficiently 'P', an Ivatt flavoured 'Coronation' or Stanier 'Turbomotive' (though with a more convincing reversing turbine than the original!).

    *term used with all due apologies to those highly skilled and dedicated designers and builders of steam locos!
     
    jnc likes this.
  17. Chris86

    Chris86 Member

    Joined:
    Oct 31, 2011
    Messages:
    692
    Likes Received:
    305
    Occupation:
    Outdoor Pursuits and Technical rescue
    Location:
    Wherever the work is.
    I'd probably rather see a recreation of one of the last batch of the Caprotti Black 5s with a few tweaks to get the best out of the arrangement.

    Chris
     
  18. sir gilbert claughton

    sir gilbert claughton Member

    Joined:
    Jan 17, 2017
    Messages:
    772
    Likes Received:
    385
    Gender:
    Male
    Occupation:
    retired
    Location:
    east sussex
    Heritage Railway Volunteer:
    No I do not currently volunteer
    if only they weren't so ugly
     
  19. 30854

    30854 Part of the furniture

    Joined:
    Mar 8, 2017
    Messages:
    3,437
    Likes Received:
    3,365
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Brighton&Hove
    Heritage Railway Volunteer:
    No I do not currently volunteer
    No objections from this direction (rather like the reasoning too) ..... from what I've seen on other threads, I was beginning to get the impression that nowt under 8P is considered of any use round these parts, but as this is 71000's thread.... :)
     
  20. Chris86

    Chris86 Member

    Joined:
    Oct 31, 2011
    Messages:
    692
    Likes Received:
    305
    Occupation:
    Outdoor Pursuits and Technical rescue
    Location:
    Wherever the work is.

    I rather like them.......
     

Share This Page