Union Pacific - Big Boy 4014

Discussion in 'International Transport' started by RBSN, 17 May 2015.

Thread Status:
Not open for further replies.
  1. RBSN

    RBSN Member

    Messages:
    241
    Joined:
    14 Jul 2014
    Hello everyone,


    How many of these amazing loco's are still operational? And do the UK or Europe have something as big or heavy duty as the 4014?

    I'm amazed by the engineering behind it and would like to learn more.

    :)
     
  2. CarltonA

    CarltonA Member

    Messages:
    445
    Joined:
    22 Apr 2012
    Location:
    Gerrards Cross
  3. ac6000cw

    ac6000cw Established Member

    Messages:
    1,324
    Joined:
    10 May 2014
    Location:
    Cambridge, UK
    None (yet) - 4014 will be the first since they were retired from normal service.

    No - it wouldn't fit through the bridges/tunnels etc. (the Big Boys are too large to run everywhere on the US rail system as well, as far as I know).
     
  4. Ploughman

    Ploughman Established Member

    Messages:
    1,846
    Joined:
    15 Jan 2010
  5. Taunton

    Taunton Established Member

    Messages:
    2,481
    Joined:
    1 Aug 2013
    However, they were built by Alco, in Schenectady (near Albany), upstate New York, so had to make their delivery run on the New York Central and Chicago & North Western to get to Omaha in Nebraska. I don't recollect any gauge issues, the big problem with these locos is curves, particularly reverse curve crossovers.
     
  6. ac6000cw

    ac6000cw Established Member

    Messages:
    1,324
    Joined:
    10 May 2014
    Location:
    Cambridge, UK
    Good point - I was aware of the crossover curve problem, but had forgotten they were built 'back East' :)
     
  7. Taunton

    Taunton Established Member

    Messages:
    2,481
    Joined:
    1 Aug 2013
    The front eight-wheel set of driving wheels in the 4-8-8-4 configuration is effectively on a bogie, mounted on slides, with flexible steam pipes to the cylinders (must be a challenge for the fitters at 300 psi keeping these steam tight). I did once see a photograph of one, taken along the loco side, with it stationary on a crossover, and the displacement of the front "engine" as they were termed was quite considerable. Do I recall correctly that some of the driving wheels were flangeless.

    I understand they only had one throttle, and one of their issues was that one of the engines might slip while the other was still driving, which would cause all sorts of pressure imbalances in the steam piping.
     
  8. 55z

    55z Member

    Messages:
    135
    Joined:
    21 Nov 2014
    It is due out for the Union Pacific celebrations in 2018.
     
  9. ianhr

    ianhr Member

    Messages:
    496
    Joined:
    17 Sep 2013
    I think the largest steam loco constructed in Europe would probably be the Soviet AA20-1 which was a 4-14-4! I gather it was not a success, whereas the UP Big Boys were arguably very successful for their rather specialised purpose.
     
  10. ac6000cw

    ac6000cw Established Member

    Messages:
    1,324
    Joined:
    10 May 2014
    Location:
    Cambridge, UK
    UP also had some 4-12-2 locos which were reasonably successful hauling trains across the 'flatlands', but I think they felt that was as far as a practical rigid-wheelbase loco could be pushed in design terms.

    Most of the 'mountain' railroads went down the Mallet-style articulated route eventually - usually using single expansion instead of true Mallet compounding (due to simpler maintenance), but the Norfolk & Western always used compounding for better fuel economy.
     
  11. SWTH

    SWTH Member

    Messages:
    411
    Joined:
    12 Mar 2013
    Location:
    Shrewsbury/Porthmadog/Exeter
    Most multi-cylinder articulated locomotives only have one regulator for both engines - double Fairlies are the only design to have separate regulators for each end. If I remember correctly Beyer Peacock offered twin regulators as an option on Garratts, but I don't think any were built with them.
     
Thread Status:
Not open for further replies.

Share This Page