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.

P2 Locomotive Company and related matters

Discussion in 'Steam Traction' started by class8mikado, Sep 13, 2013.

  1. S.A.C. Martin

    S.A.C. Martin Part of the furniture

    Joined:
    Aug 31, 2010
    Messages:
    3,639
    Likes Received:
    4,952
    Gender:
    Male
    Occupation:
    Apprentice Rail Engineer, MNLPS Treasurer, Author
    Location:
    Sidcup, Kent
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    I think a better term might be "adequately" - there is argument that had not the number of Lentz fitted D49s been so high, and WW2 intervened, they would have all been rebuilt as walschaerts fitted examples. There's certainly not much to choose between the two sub classes historically.
     
  2. 240P15

    240P15 Well-Known Member

    Joined:
    Dec 1, 2017
    Messages:
    1,350
    Likes Received:
    1,269
    Gender:
    Male
    Location:
    Norway
    Heritage Railway Volunteer:
    No I do not currently volunteer
    deleted
     
    Last edited: Oct 23, 2018
  3. class8mikado

    class8mikado Well-Known Member

    Joined:
    Jun 1, 2009
    Messages:
    3,022
    Likes Received:
    1,030
    Occupation:
    Print Estimator/ Repository of Useless Informatio.
    Location:
    Bingley W.Yorks.
    Heritage Railway Volunteer:
    No I do not currently volunteer
    The Franklin gear is closer to the reidinger gear fitted to half a dozen Crabs than the prewar Lentz. Indeed only the willingness to refine the caprotti to a more acceptable solution(i.e the last two black 5s) again postwar together with a bit of golf course diplomacy got the caprotti on the Standards but both BR Caprotti and Reidinger were a lot more advanced than prewar versions...
     
  4. RLinkinS

    RLinkinS Member

    Joined:
    Nov 8, 2008
    Messages:
    560
    Likes Received:
    613
    Gender:
    Male
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Yes, he did build them in all three gauges, starting with the largest. He also built a standard class 5 in 5" with Caprotti gear.. Apparenty he built quite alot of the 7.25" gauge one in a remote part of Nigeria with quite limited equipment.
     
    Bluenosejohn likes this.
  5. 242A1

    242A1 Member

    Joined:
    Dec 3, 2006
    Messages:
    1,291
    Likes Received:
    856
    The LNER experimented with valve gears rather more than an outsider might think. In 1926 Lentz poppet valves were fitted to an ex-GER 4-6-0. These were driven by Stephensons gear and were of the oscillating cam type. Six more engines were converted between 1928 and 1930 and based on the reports that the early conversions ran noticeably increased mileages between repairs than their piston valve fitted contemporaries a new batch of ten B12s were built in 1928 fitted with the new gear. As with so many things the first impressions deceived. Drivers complained and inspectors sallied forth. There were mechanical issues including cylinder cracking and the engines were found to be seriously lacking when it came down to the ability to climb the steeper grades. A return to piston valves was ordered.

    Some observers maintain that the GCR 4 cylinder 4-6-0s were rather poor engines with very high fuel consumption. Others, including the late Dick Hardy would have none of it, what was needed was a driver that understood how to use them. In 1929 two of the B3 class were fitted with Caprotti gear, numbers 6166 and 6168. this gear, supplied by Beardmores, was identical to that used on some Claughtons by the LMS. In this gear the valves were spring operated and the design was basically as Arturo introduced it in 1922. The springs did weaken under the action of high temperature steam and there were breakages. The cam operating scrolls were originally cast iron and these also failed but the application of bronze scrolls solved this problem. These two engines were reportedly low on maintenance and were well liked. Some arrangement was needed to help with air flow to help to keep the cam boxes cool. The Caprotti fitted engines were between 9.6% and 15.65% improved in fuel consumption when measured over 1931 - 1934 depending on whether they were working in the same link or otherwise.

    Trials were organised in March 1936 between 6166 and the piston valve fitted 6169 using the same grade of coal over the same route. here the Caprotti fitted engine had a 21.9% advantage.

    Though we have lbs/mile figures and details of the load and route we have no figures for fuel per unit of power output. But Gresley ordered two further conversions, 6164 and 6167, and these took place in 1938. These two engines had a revised gear fitted. Steam operation of the valves replaced the springs and the cam boxes were strengthened with harder wearing surfaces and better oil seals.. These engines were also well liked and an enthusiastic Woodford shed master set about recording much detail of their performance. However WW2 washed all this work away. The LNER learned enough from the two sets of conversions to realise that the second pair were much superior and they set about a third design which amongst other things addressed the issue of excessive clearance volumes with the intention of converting all the B3 and B7 class members.

    Excess clearance volumes was a problem on the B3 conversions and also on 2001 but in terms of mechanical dependability it appears that the LNER were making progress. The B3 conversions, particularly the second pair, appear to have performed rather well, certainly better than 71000 which has been beset by peculiar valve issues more than once. Possibly the LNER had an engineering team that was far better than its rather poor financial status would suggest.
     
  6. 240P15

    240P15 Well-Known Member

    Joined:
    Dec 1, 2017
    Messages:
    1,350
    Likes Received:
    1,269
    Gender:
    Male
    Location:
    Norway
    Heritage Railway Volunteer:
    No I do not currently volunteer
  7. Allegheny

    Allegheny New Member

    Joined:
    May 8, 2015
    Messages:
    450
    Likes Received:
    188
    Gender:
    Male
    Heritage Railway Volunteer:
    No I do not currently volunteer
  8. MarkinDurham

    MarkinDurham Member

    Joined:
    May 4, 2007
    Messages:
    2,127
    Likes Received:
    885
    Location:
    Durham
    Sadly, Brian Blessed notwithstanding, I fear that this project is a VERY long term one, especially given how the 2007 build has so speedily progressed.
     
    Gav106 and 2392 like this.
  9. Kinghambranch

    Kinghambranch Well-Known Member

    Joined:
    Dec 20, 2006
    Messages:
    1,845
    Likes Received:
    1,433
    Gender:
    Male
    Occupation:
    Retired
    Location:
    White Rose County
    Heritage Railway Volunteer:
    No I do not currently volunteer
    A friend of mine had kindly arranged for 3 of us to visit the P2 facility at Darlington Locomotive Works today. 2007's wheels had been moved out for further work including the fitting of balance weights, but the whole appearance of this locomotive is, in my view, simply awesome, even without its tender, work on which is planned to commence next year. The whole operation is most professional and there is no doubt in my mind that 2007 will roll out in full working order in 2021 if we all support the scheme. We were very grateful to Lee for showing us round and, I was so impressed, I have decided to sign up and join (I can't believe it really as this is no Swindon loco!). I'll just have to cut down on beer but it will be worth it!

    We also visited the nearby Darlington Railway Museum ("Head of Steam") at the old North Road Station. As it was my first visit I was very glad to go but, as it's Halloween, or something, soon, they had festooned most of the place with "spooky tat" which didn't help photography!
    20181026-10-.JPG
     

    Attached Files:

    Last edited: Oct 26, 2018
    240P15, Bluenosejohn, Tobbes and 4 others like this.
  10. 240P15

    240P15 Well-Known Member

    Joined:
    Dec 1, 2017
    Messages:
    1,350
    Likes Received:
    1,269
    Gender:
    Male
    Location:
    Norway
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Richard Roper likes this.
  11. W.Williams

    W.Williams Well-Known Member

    Joined:
    Dec 20, 2015
    Messages:
    1,380
    Likes Received:
    1,119
    Occupation:
    Mechanical Engineer
    Location:
    Aberdeen
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    "Re-routing the steam and exhaust passages to physically separate them to prevent incoming steam from heating the outgoing exhaust"

    Surely that is the wrong way around from a thermodynamics perspective, to prevent incoming steam from being cooled by the outgoing exhaust seems more logical no?

    Post Weld Heat Treat (PWHT) is going to be interesting on this, its a big old block with a lot of welds.
    Do you do an intermediate PWHT or stick it all together and hope you can get all the residuals out at the end?

    I say this in the light of the recent Tornado findings of bore concentricity/angularity/tolerance stack.

    There is a big incentive to get the residual stresses out of this fabrication as much as reasonably practicable to ensure the required geometry is stable and envisioned tolerances are achievable.

    A pre-weld heat up probably a good shout too.

    Is that a simplified saddle model for sake of ease or is it going to be that shape?
     

    Attached Files:

    Last edited: Oct 30, 2018
    ragl, jnc and 240P15 like this.
  12. LMS2968

    LMS2968 Part of the furniture

    Joined:
    Sep 1, 2006
    Messages:
    2,543
    Likes Received:
    3,425
    Gender:
    Male
    Occupation:
    Lecturer retired: Archivist of Stanier Mogul Fund
    Location:
    Wigan
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    It's the same thing whichever way you say it - heat transfer from the live to the exhaust steam sides.
     
  13. Jamessquared

    Jamessquared Nat Pres stalwart

    Joined:
    Mar 8, 2008
    Messages:
    20,101
    Likes Received:
    35,907
    Location:
    215
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Entropy, entropy, they've all got it entropy …

    Tom (with apologies to Kenneth Williams, and indeed my thermodynamics tutor ;)
     
    Last edited: Oct 30, 2018
  14. 5944

    5944 Part of the furniture

    Joined:
    Jan 14, 2006
    Messages:
    5,683
    Likes Received:
    2,897
    Gender:
    Male
    Occupation:
    Train Maintainer for GTR at Hornsey
    Location:
    Letchworth
    Heritage Railway Volunteer:
    No I do not currently volunteer
    And apologies to Kenneth Williams too? ;)
     
  15. Jamessquared

    Jamessquared Nat Pres stalwart

    Joined:
    Mar 8, 2008
    Messages:
    20,101
    Likes Received:
    35,907
    Location:
    215
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Him as well :oops:

    Tom
     
    andrewshimmin, LMS2968 and 5944 like this.
  16. Steve

    Steve Part of the furniture Friend

    Joined:
    Oct 7, 2006
    Messages:
    10,248
    Likes Received:
    6,653
    Occupation:
    Gentleman of leisure, nowadays
    Location:
    Near Leeds
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    A line originally uttered by Jimmy Edwards.
     
  17. Quicksilver2510

    Quicksilver2510 New Member

    Joined:
    Aug 28, 2017
    Messages:
    36
    Likes Received:
    96
    Gender:
    Male
    Location:
    Burbage
    Heritage Railway Volunteer:
    No I do not currently volunteer
  18. Eightpot

    Eightpot Well-Known Member Friend

    Joined:
    Aug 10, 2006
    Messages:
    6,947
    Likes Received:
    1,439
    Location:
    Aylesbury
  19. Sheff

    Sheff Well-Known Member

    Joined:
    Apr 21, 2006
    Messages:
    7,167
    Likes Received:
    1,760
    Gender:
    Male
    Occupation:
    Retired Engineer & Heritage Volunteer
    Location:
    N Warks
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Is it not?
     
  20. paullad1984

    paullad1984 Member

    Joined:
    Oct 16, 2007
    Messages:
    844
    Likes Received:
    356
    Did I hear someone sharpening an axe....?
     

Share This Page