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.

The Kings' bogies

Discussion in 'Steam Traction' started by MellishR, Oct 16, 2015.

  1. MellishR

    MellishR Resident of Nat Pres Friend

    Joined:
    Apr 16, 2009
    Messages:
    8,068
    Likes Received:
    5,164
    The reason that is usually cited for the Kings' odd bogies, with outside frames at the front and inside frames at the rear, is that it was necessary to allow room for the cylinders. However the nominal cylinder diameter of the Kings is only a quarter inch more than that of the Castles, and the first series of Stanier Pacifics had the same cylinder size as the Kings, and more or less the same De Glehn layout. So why did the Kings need that feature when the Castles and Princesses didn't?
     
  2. Jimc

    Jimc Part of the furniture

    Joined:
    Sep 8, 2005
    Messages:
    4,052
    Likes Received:
    4,665
    Occupation:
    Once computers, now part time writer I suppose.
    Location:
    SE England
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Worth remembering that the Kings were designed against a tight deadline. If you don't find a better solution within a tight deadline you're stuck with the one you first thought of... FWIW Nock says that they wanted a plate frame bogie, unlike the Castles and it was fitting the plate frames in that in that proved difficult.
     
  3. meeee

    meeee Member

    Joined:
    Mar 28, 2006
    Messages:
    864
    Likes Received:
    1,319
    Perhaps that extra 1/4 of an inch means the inside cylinders have to sit lower down in the frames in order to keep the valves at the same height. They are also 2 inches longer than a Castle.
     
  4. Reading General

    Reading General Part of the furniture

    Joined:
    May 18, 2011
    Messages:
    6,081
    Likes Received:
    2,217
    The King's Bogies? what a subject to pick...s'not funny.
     
    Gav106, pmh_74, Corbs and 1 other person like this.
  5. 8126

    8126 Member

    Joined:
    Mar 17, 2014
    Messages:
    823
    Likes Received:
    962
    Gender:
    Male
    The driving wheel diameter on the Kings is 2.5" less than the Castles, so the cylinder centreline is 1.25" lower. The GWR bar frame bogie may simply not have fitted, it has a cross member up front at the top of the frame. The Princesses seem to have a plate-framed bogie with equaliser beams, whereas the King bogie has separate springs. I think the Modified Hall bogie is also separately sprung. All things being equal, I reckon you can get away with less height inboard of the wheels using equaliser beams than without. If Collet's team wanted to do away with the equaliser beams, what they did may have been the only viable solution.
     
  6. Jimc

    Jimc Part of the furniture

    Joined:
    Sep 8, 2005
    Messages:
    4,052
    Likes Received:
    4,665
    Occupation:
    Once computers, now part time writer I suppose.
    Location:
    SE England
    Heritage Railway Volunteer:
    No I do not currently volunteer
    What Nock says is that they'd been experiencing breaking rivets with the bar frame bogie, and that was the reason for moving to plate frames. Later on, however, they found a cure for the Castle bogie issues, although its interesting to note that the Modified Halls also had a plate frame bogie.
     
    Selsig likes this.
  7. 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
    The Princesses (and Duchesses) had a bar frame bogie very similar to the GWR version which was itself a copy of American practice. There is a drawing of one on the last page of www.railwaysarchive.co.uk/documents/MoT_Weedon1951.pdf, the faulty assembly of the bogie wheelsets being the cause of the accident.
     
  8. 99Z

    99Z Guest

    deleted
     
    Last edited by a moderator: Nov 8, 2015
    Gav106, Reading General and Matt37401 like this.
  9. 8126

    8126 Member

    Joined:
    Mar 17, 2014
    Messages:
    823
    Likes Received:
    962
    Gender:
    Male
    I stand corrected. That drawing does show an interesting difference between the LMS and GWR bogies, in that the LMS version has a cast or fabricated end stretcher, which is depressed in the centre, whereas the Castle bogie has a flat top bar at the end and bar braces below (this is a Manor bogie, but pictures of Castles indicate the same). The depressed centre on the LMS bogie stretcher would almost certainly have been to get clearance relative to something.
     
  10. LesterBrown

    LesterBrown Member

    Joined:
    Jan 20, 2009
    Messages:
    995
    Likes Received:
    761
    Location:
    Devon
    I wonder if the longer coupled wheelbase of the Kings was also a factor, necessitating more clearance for curves?
     
  11. Gav106

    Gav106 Well-Known Member

    Joined:
    Mar 29, 2010
    Messages:
    1,741
    Likes Received:
    2,017
    Location:
    Nantwich, Cheshire
    If this thread about Bogies is anything like the other threads on Nat pres it will keep running and running......
     

Share This Page