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.

Locomotive Boilers and Boiler Pressure

Discussion in 'Steam Traction' started by 30854, Oct 31, 2017.

  1. 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
    @S.A.C. Martin Some very intersesting points. Given that curved sections of metal withstand pressure better than flat surfaces, I wonder how that reflects in construction technique, staying arrangements and which has the greater bearing in regard to ongoing maintenance costs of otherwise similar boilers.

    Woefully lacking in knowledge of LNER pracitses, I note the substantial difference in size between the original Holden S69 (B12/1) boiler and that of the Gresley/Thompson B12/3 rebuilds, but have no handle on whether ex-GCR reboilerings would allow better direct comparison of maintenence costs.

    If records survive in Ireland, the ex-MGWR K Class (GSR/CIÉ G2/650) should provide a good indication, as class members ran with a mixture of interchangable round topped (saturated and superheated varieties) and Belpaire boilers. AIUI, all extant records are now in the care of the IRRS (http://www.irrs.ie) should anyone feel the need to investigate the matter in depth.

    Edit: In light of Eightpot's post (below), I'd best add that taper boilers in the south were confined to GSR/CIÉ classes 305, 309/310,321/332 and 333 as built and all were replaced with parallel boilers. A vanishingly rare example of a locomotive policy actually being applied across the board!
     
    Last edited: Oct 31, 2017
  2. Eightpot

    Eightpot Resident of Nat Pres Friend

    Joined:
    Aug 10, 2006
    Messages:
    8,077
    Likes Received:
    2,264
    Gender:
    Male
    Occupation:
    Engineer Emeritus
    Location:
    Aylesbury
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Agreed, but one difference hasn't been commented upon as yet. The Belpaire boilers that the LNER had as fitted to GC and GE locos all had parallel barrels and outer firebox wrappers. To suddenly have to build boilers with not only taper barrels, but also outer firebox wrappers (and inner fireboxes too) that not only sloped down front to back, but tapered in along the sides as well, must have caused some headaches for those actually making this type for the first time. I think it was Thompson who stated that this type (8F) boiler cost something in the region of 70% more than an equivalent parallel round-topped firebox type.

    This extra time and cost involved was presumably a factor noted by Riddles as the WD 2-8-0s and 2-10-0s came out with parallel and round-topped boilers.
     
    S.A.C. Martin and 30854 like this.
  3. Cartman

    Cartman Well-Known Member Account Suspended

    Joined:
    Dec 14, 2015
    Messages:
    2,290
    Likes Received:
    1,672
    Gender:
    Male
    Occupation:
    Van driver
    Location:
    Cheshire
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Yes, Ive heard that before. The WD 2-8-0 was basically a cheapened and more basic version of an 8F
     
  4. 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
    .... but still looked well enough in unlined BR black, when clean! :)
     
    Cartman likes this.
  5. NOOOO! Don't get him started...:Nailbiting:
    Oh no, too late... :Facepalm:
    :Muted:
     
    paullad1984, Bill Drewett and 2392 like this.
  6. paulhitch

    paulhitch Guest

    Martin, do you really think of doing things like that? Shame on you.

    Paul H
     
  7. 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
    Sorry. :oops:
     
    DisusedBranch, Bill Drewett and 2392 like this.
  8. Cartman

    Cartman Well-Known Member Account Suspended

    Joined:
    Dec 14, 2015
    Messages:
    2,290
    Likes Received:
    1,672
    Gender:
    Male
    Occupation:
    Van driver
    Location:
    Cheshire
    Heritage Railway Volunteer:
    No I do not currently volunteer
    I only ever remember seeing some of 26D's allocation of them, in a VERY dirty state
     
    30854 likes this.
  9. 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
    In pretty much every shot I've seen from their service days they were absolutely filthy. The first time I saw one looking presentable was ex-SJ "90733" in preservation. Not exactly a typical example of the breed, I'll grant you, but ..... who cares? :)
     
    Cartman likes this.
  10. Cartman

    Cartman Well-Known Member Account Suspended

    Joined:
    Dec 14, 2015
    Messages:
    2,290
    Likes Received:
    1,672
    Gender:
    Male
    Occupation:
    Van driver
    Location:
    Cheshire
    Heritage Railway Volunteer:
    No I do not currently volunteer
    That one looks superb, a fantastic job by the KWVR on another one of my favourite loco classes
     
    17B, Kinghambranch and 30854 like this.
  11. huochemi

    huochemi Part of the furniture

    Joined:
    May 6, 2008
    Messages:
    2,751
    Likes Received:
    1,393
    Gender:
    Male
    Location:
    UK
    Heritage Railway Volunteer:
    No I do not currently volunteer
    ? Is there anything similar apart from the whistle?
     
  12. 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
    Smokebox ? wheel arrangement perhaps ?
     
  13. Cartman

    Cartman Well-Known Member Account Suspended

    Joined:
    Dec 14, 2015
    Messages:
    2,290
    Likes Received:
    1,672
    Gender:
    Male
    Occupation:
    Van driver
    Location:
    Cheshire
    Heritage Railway Volunteer:
    No I do not currently volunteer
    The design was derived from it, proportions, etc, designed to do the same job, but much cheaper to build
     
    30854 likes this.
  14. martin1656

    martin1656 Nat Pres stalwart Friend

    Joined:
    Dec 8, 2014
    Messages:
    17,609
    Likes Received:
    11,223
    Gender:
    Male
    Location:
    St Leonards
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Side stepping the 8f vs WD , what were the most powerful of the Atlantic's it would be interesting to compare each designers loco, for instance i would imagine the brighton engines would be very simular to the LNER ones
     
  15. 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
    I suspect the ex-LBSC, ones once BP was increased, but I'd put money on nothing here coming remotely close to the Milwaukee RR 'A Class' (Image credited to coffeeasap.com):

    Hiawatha.jpg.cf.jpg
     
  16. huochemi

    huochemi Part of the furniture

    Joined:
    May 6, 2008
    Messages:
    2,751
    Likes Received:
    1,393
    Gender:
    Male
    Location:
    UK
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Or the Pennsylvania E6.
     
  17. 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
    Hell's donkeys ..... I think you're right. They're monsters! :Wideyed:
     
  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
    Marsh certainly wasn't alone in applying a popular notion that superheated locos could utilise lower boiler pressure than otherwise similar saturated locos. It was pretty common over on the GS&WR too. Whether the reasoning was fuel economy, maintenence savings or a combination of both seems moot, as the idea seems to have died a natural death by the 20's in any event.
     
  19. andrewshimmin

    andrewshimmin Well-Known Member

    Joined:
    Mar 18, 2011
    Messages:
    1,761
    Likes Received:
    2,160
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Also tangential, sorry, but...
    I understand Stanier's firebox/boiler designs (i.e. Swindon!) were found to be cheaper to maintain than parallel boilers with round-topped or belpaire fireboxes because e.g. their stays lasted longer. Certainly the LMS accountants thought they were worth the money - after checking the sums.
     
  20. Eightpot

    Eightpot Resident of Nat Pres Friend

    Joined:
    Aug 10, 2006
    Messages:
    8,077
    Likes Received:
    2,264
    Gender:
    Male
    Occupation:
    Engineer Emeritus
    Location:
    Aylesbury
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    This from raising steam on the LMS by A. F. Cook. Certainly the narrow firebox Stanier boilers come our well especially when compared with their similar ones on the GWR 'Hall' and 28XX 2-8-0s. The LNER 100A boiler better than the comparable GWR types. Note also the variation between the same (100A) and similar (5MT and 8F) boiler when divided between passenger and freight locos.

    However, when it comes to the wide firebox types the list is headed by the SR Bullied and LNER A1 and A2 Pacifics with the 'Duchess' right at the bottom.

    Scan 113.jpg
     

Share This Page