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.

BR Standard class 6 No. 72010 'Hengist' and Clan Discussion Thread

Discussion in 'Steam Traction' started by Bulleid Pacific, Nov 23, 2009.

  1. Matt37401

    Matt37401 Nat Pres stalwart

    Joined:
    Jun 8, 2014
    Messages:
    15,326
    Likes Received:
    11,663
    Occupation:
    Nosy aren’t you?
    Location:
    Nowhere
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Do you think those doing train of lights have a strobe effect on them? :p Bit of Prodigy and Chemical Brothers and your away!
     
  2. class8mikado

    class8mikado Part of the furniture

    Joined:
    Jun 1, 2009
    Messages:
    3,609
    Likes Received:
    1,438
    Occupation:
    Print Estimator/ Repository of Useless Informatio.
    Location:
    Bingley W.Yorks.
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Its only a matter before someone posts a link to 'Cyber goths dance to Thomas the tank engine '

    oops
     
  3. Mandator

    Mandator Part of the furniture

    Joined:
    Feb 12, 2015
    Messages:
    4,868
    Likes Received:
    3,043
    Gender:
    Male
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Cool

    Sent from my SM-J330FN using Tapatalk
     
  4. Bikermike

    Bikermike Well-Known Member

    Joined:
    Mar 11, 2020
    Messages:
    1,442
    Likes Received:
    1,595
    Gender:
    Male
    Location:
    Thameslink territory
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Interesting to see the boiler modelling work. Isn't the boiler the principal divergence from the Britannia design?
     
  5. Sheff

    Sheff Resident of Nat Pres

    Joined:
    Apr 21, 2006
    Messages:
    7,567
    Likes Received:
    2,345
    Gender:
    Male
    Occupation:
    Retired Engineer & Heritage Volunteer
    Location:
    N Warks
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Smaller firebox. Otherwise very similar. Iirc.
     
  6. Bikermike

    Bikermike Well-Known Member

    Joined:
    Mar 11, 2020
    Messages:
    1,442
    Likes Received:
    1,595
    Gender:
    Male
    Location:
    Thameslink territory
    Heritage Railway Volunteer:
    No I do not currently volunteer
    I thought (he says arguing from a position of ignorance), the smaller boiler was how they got the weight down to improve route availability?
     
    LMS2968 likes this.
  7. class8mikado

    class8mikado Part of the furniture

    Joined:
    Jun 1, 2009
    Messages:
    3,609
    Likes Received:
    1,438
    Occupation:
    Print Estimator/ Repository of Useless Informatio.
    Location:
    Bingley W.Yorks.
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Sure there is a very small list of differences, most of which being boiler related, but essentially its a smaller firebox and the barrel sections are just as long but not as wide...
     
  8. Sheff

    Sheff Resident of Nat Pres

    Joined:
    Apr 21, 2006
    Messages:
    7,567
    Likes Received:
    2,345
    Gender:
    Male
    Occupation:
    Retired Engineer & Heritage Volunteer
    Location:
    N Warks
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Isn’t a significant factor the lower boiler pressure which translates to thinner plate?


    Sent from my iPhone using Tapatalk
     
    Jamessquared likes this.
  9. 'Clan' Hengist

    'Clan' Hengist New Member

    Joined:
    Oct 23, 2014
    Messages:
    72
    Likes Received:
    211
    Gender:
    Male
    Occupation:
    Train Driver, Member Hengist Management Team
    Location:
    East Midlands
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    In a word - no. We have the calculations as to plate thickness with regard to pressure. There is less than half a millimetre difference in one plate section and the rest are the same. That is for 225 psi and 250 psi boilers. Boiler pressure is irrelevant in this context.
     
    Sheff likes this.
  10. Sheff

    Sheff Resident of Nat Pres

    Joined:
    Apr 21, 2006
    Messages:
    7,567
    Likes Received:
    2,345
    Gender:
    Male
    Occupation:
    Retired Engineer & Heritage Volunteer
    Location:
    N Warks
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    I thought we were talking about the originals and there was a difference?


    Sent from my iPhone using Tapatalk
     
  11. 'Clan' Hengist

    'Clan' Hengist New Member

    Joined:
    Oct 23, 2014
    Messages:
    72
    Likes Received:
    211
    Gender:
    Male
    Occupation:
    Train Driver, Member Hengist Management Team
    Location:
    East Midlands
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    My comment stands. Plate would have been supplied in standard thicknesses just as it is now. No point in thinning down a plate a fraction. Just use what was supplied. In other words, the plates of the originals would have been the same material thickness for both Britts and Clans. Just rolled to a different diameter.
     
  12. LMS2968

    LMS2968 Part of the furniture

    Joined:
    Sep 1, 2006
    Messages:
    2,987
    Likes Received:
    5,084
    Gender:
    Male
    Occupation:
    Lecturer retired: Archivist of Stanier Mogul Fund
    Location:
    Wigan
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Not too sure on that. When the Black Fives were on the board, weight was deemed to be critical, sufficient that HT instead of normal boiler steel was specified. This allowed about 1/16" thinner plates to be used. It needed careful design work to allow the existing flanging blocks to be used.
     
    andrewshimmin likes this.
  13. 'Clan' Hengist

    'Clan' Hengist New Member

    Joined:
    Oct 23, 2014
    Messages:
    72
    Likes Received:
    211
    Gender:
    Male
    Occupation:
    Train Driver, Member Hengist Management Team
    Location:
    East Midlands
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    I'm going to leave it to Ian our technical guy to pick this up. He is an engineer and can give better answers than I as he has access to all the tech data and relevant drawings. I'll drop him an email and ask him to look and comment.
     
  14. std tank

    std tank Part of the furniture

    Joined:
    Sep 20, 2005
    Messages:
    3,807
    Likes Received:
    946
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Liverpool
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Afraid not.
    Britannia Class 250 psi pressure. Front barrel 19/32" thick. Rear Barrel 21/32" thick.
    Clan Class 225 psi pressure. Front Barrel 1/2" thick. Rear Barrel 9/16" thick.
    Material is low alloy high tensile steel 34 ton minimum.
     
    andrewshimmin and Sheff like this.
  15. LMS2968

    LMS2968 Part of the furniture

    Joined:
    Sep 1, 2006
    Messages:
    2,987
    Likes Received:
    5,084
    Gender:
    Male
    Occupation:
    Lecturer retired: Archivist of Stanier Mogul Fund
    Location:
    Wigan
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Sorry, I didn't mean to cast doubt on the Clan drawings, but making the general comment that the odd fraction of an inch could make a measurable difference in weight. If weight isn't a factor, then use the same standard thickness. In that case, the possible cost of new flanging blocks would be the more critical parameter.
     
  16. ianh1

    ianh1 Member

    Joined:
    May 10, 2018
    Messages:
    218
    Likes Received:
    673
    Gender:
    Male
    Location:
    Cumbria
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    These days, boiler plate comes in metric sizes. Yes, the boiler pressure is directly related to the wall thickness but the limitation comes in the sizes that are commercially available. So for the front barrel ring which is parallel, the formula gives a result of 10.06mm thick for a 225psi boiler and a result of 11.1mm thick for a 250psi boiler. We have to round up to the nearest commercially available size which is 12mm in both cases. For the rear barrel which is tapered and larger at the rear (it also has a hole for the dome), the calculated thickness 12.3mm for 225 psi and 13.5mm for 250 psi. Round up to 15mm in both cases. Therefore, for the boiler barrel, the actual plate thickness will be the same for a 225 psi boiler and a 250 si boiler.

    We're still doing the calculations for the firebox but we know that a few plates will have to be thicker for the 250 psi boiler
     
  17. Bikermike

    Bikermike Well-Known Member

    Joined:
    Mar 11, 2020
    Messages:
    1,442
    Likes Received:
    1,595
    Gender:
    Male
    Location:
    Thameslink territory
    Heritage Railway Volunteer:
    No I do not currently volunteer
    It's not too late to turn it into a Brit then? <fx: runs away>

    Mildly interesting thought occurs, if more clans had been built, what would they have replaced? would there have been less Britannias built? less std 5s?
     
  18. 30854

    30854 Resident of Nat Pres

    Joined:
    Mar 8, 2017
    Messages:
    12,172
    Likes Received:
    11,493
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Brighton&Hove
    Heritage Railway Volunteer:
    No I do not currently volunteer
    There'd probably have been fewer Bulleid light pacifics rebuilt ..... if any!
     
  19. Jamessquared

    Jamessquared Nat Pres stalwart

    Joined:
    Mar 8, 2008
    Messages:
    26,099
    Likes Received:
    57,414
    Location:
    LBSC 215
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    I think the consideration for rebuilding the Merchant Navies considered that (or rather, scrap the MNs and build more Britannias) but rebuilding the MNs worked out more cost effective. The difference in physical form shouldn't disguise the fact that the vast majority of an original Bulleid Pacific could transfer unchanged into the rebuilt locos.

    Tom
     
    andrewshimmin, Steve and 30854 like this.
  20. Flying Phil

    Flying Phil Part of the furniture

    Joined:
    Dec 10, 2018
    Messages:
    2,696
    Likes Received:
    5,500
    Gender:
    Male
    Location:
    Leicestershire
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    The "average re-building cost of a Bulleid Pacific was £8500 over the cost of the general repair" according to Boocock and this was paid off in approx 7 years of savings compared to "originals".
    I suspect the cost of new "Clans" was more than the £8500. But I am looking forward to seeing how "Hengist" performs.
     
    30854 likes this.

Share This Page