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Dukedogs

Discussion in 'Steam Traction' started by Martin Perry, Apr 28, 2009.

  1. Martin Perry

    Martin Perry Nat Pres stalwart Staff Member Moderator Friend

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    With 9017 having been much in the news lately, it got me wondering exactly what was the rationale behind the creation of the class in the first place. I understand that there was a requirement for new(er) traction for the Cambrian lines and that the Granges/43XX/Bulldogs etc were not suitable for the route due to axle weight etc etc, but why combine the boiler of the Duke of Cornwall class with the Bulldog frames? Would it not have produced something similar just to have refurbished the Duke of Cornwall class locos - or were they so mechanically decrepit (but with good boilers!) that this was not practical? Appreciate any info/opinions etc.
     
  2. LesterBrown

    LesterBrown Member

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    By then the outside frames of the Dukes had been fitted with strengthening patches (as indeed had the Bullldogs with their heavier boilers). The next stage in prolonging the life of the Dukes might have been new frames but as the Bulldogs had been built with deeper frames, were newer and were being displaced by six-coupled locos the creation of the Dukedog/Earls has a certain logic. The second batch of Dukedogs didn't use old Duke boilers but had new ones built for them. In the end a few of the old Dukes lasted almost as long as their successors.

    A more puzzling rebuilding to my mind was the conversion of existing Atbaras to Cities (with the larger no 4 boiler) at the same time as new Atbaras of the Flower series were being turned out. I sometimes wonder whether Churchward was wary of building further new Cities in case it raised the question as to why they were preferred to further Counties, his equivalent new standard design but infamous for their poor riding (more Counties were built a few years later but perhaps even then the running sheds would have preferred more Cities?). Another less likely scenario might be that as the Flowers were the cheapest possible express loco. design he was trying to balance budgets in the year when the Great Bear was turned out (this assumes rebuilding costs were regarded as revenue rather than capital expenditure).
     
  3. Kerosene Castle

    Kerosene Castle Well-Known Member

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    I believe some of the early Dukedogs were also built using spare boilers, or at least those that had seen limited use?

    Interesting comment about the Cities. I suppose it could be argued (or used as an excuse) that the Counties were built for a particular niche, whereas the Cities were more for general use, although the fact is that as a modern design along the same lines, the Counties should have superceded the Cities. On paper at least!

    I wonder how much of the legend of them being rough riders is actually fact, and how much has been built up over the years. I get the feeling that with the hammering the frames would've got, it was more a case of them becoming rough in a shorter space of time, rather than them being a particularly rough design from the outset. They get unfairly dismissed in my opinion. (Mind you, I've never had to work them!)

    Oh dear, off topic already. :-#
     
  4. arthur maunsell

    arthur maunsell Well-Known Member

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    not off topic at all...keep going...this is interesting...

    Ive always assumed that the boilers on the Dukedogs werent necessarily physically lifted off their donor and on to the new loco.Any suitable boiler in the pool would have been used surely.
     
  5. ady

    ady Well-Known Member

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    Possibly the Dukedogs came about to the conservitive views of footplatemen and the workshops, i.e. it if works don't knock it. This was the easier option then coming up with either a new version or something diffrent (see Collett's 5101/2884/14xx/49xx/etc. alll 'modern versions of Churchward or older designs). Although It stricks me stange that the '2251' 0-6-0 had been around before the 'Dukedog' conversions started and I feel they would have been just has able to do the job.
     
  6. Columbine

    Columbine Member

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    I suspect, but I don't actually know, that they were a consequence of the financial position of the GWR in the 1930s. Rather than make up a new design out of capital account they simply 'made do and mended' from the resources they had. Take an existing chassis, add an existing design of standard boiler and what you have is a useful class of mixed traffic engine that could pretty well go anywhere on the GW.

    I think you also have to bear in mind that the moguls were coming to the end of their lives and the perception was that a leading bogie was needed instead of a pony truck for the future. That might have been the reason why the GW didn't actually build their equivalent of the WSR's 9351. As the GW financial position improved towards the end of the thirties the 'Manor' class was created but its route availability wasn't as good as the moguls they replaced. Eventually the Ivatt and Riddles designs did the bizz

    I would doubt if anybody expected the engines to last as long as they did though, we have WW2 to thank for that!

    Regards
     
  7. Steamage

    Steamage Part of the furniture

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    I'd have thought a 2-6-0 design would have been prefered to a 4-4-0, as having better adhesion for the same axle weight and wheelbase. Were there any severe curves in the district that ruled-out using a six-coupled design? Why weren't the existing moguls, like 7325 now on the SVR, suitable? Too heavy? Weren't there proposals for a tender version of the 51xx large prairie, which is what the WSR have now done by converting 5193 into 9351? I guess that putting newer boilers on existing Duke frames was quicker and cheaper than building a new class of light moguls.

    Now there's an idea for the WSR's proposed GWR gala: Dukedog meets Mongrel - Compare & Contrast: would a series of new 93xx moguls have done a better job than the 90xx rebuilds?
     
  8. david1984

    david1984 Resident of Nat Pres

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    Depends what variant, quite a few of the moguls had that heavy bufferbeam casting at the time (to improve front driving wheel tyre wear ?) which pushed them into the red route restriction.

    Also possible (though uncertain) that parts of the Cambrian were more restricted in GWR days than BR(W) so maybe even a standard 43XX was restricted at that time, pretty certain Manors at least were Restricted on the Phwelli road initially.
     
  9. 1472

    1472 Well-Known Member

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    What at first seems a strange decision to build these locos in the late 30's actually makes a lot of sense when you look at it because:
    a. there were plenty of displaced (from mainline work) but not life expired 4-4-0's of more modern design than the Dukes available.
    b. many of the duties for which these locos were light & even then somewhat seasonal.
    c. bogie locos were rightly prefered to 0-6-0s or 2-6-0s for riding/track wear reasons if there was a choice.
    d. thanks to standardisation there was a good range of standard boilers available.
    e. money was'nt plentiful.
    f. some of the lines were then still very restricted re axleload - such as Dovey Jct onwards to the north.

    Add in the possibility in accountancy terms of building "new" locos (but using old parts) to skirt round revenue v capital expenditure rules.

    Starts to sound like a no - brainer?
     
  10. Martin Perry

    Martin Perry Nat Pres stalwart Staff Member Moderator Friend

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    Did both classes have slide valves?
     
  11. 1472

    1472 Well-Known Member

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    9017 & the Bulldog it was rebuilt from (3425?) are/were both piston valve locos with 8" valves.

    Would guess that the Duke class were slide valve & the early Bulldogs probably were.
     
  12. Martin Perry

    Martin Perry Nat Pres stalwart Staff Member Moderator Friend

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    That gives a little more logic to the rebuild process.
     
  13. Jimc

    Jimc Part of the furniture

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    K J Cook (the works headman) goes into the background of the Dukedogs at some length in his book "Swindon Steam".

    The Dukes were needed because there was nothing available to replace them on yellow routes, even though they were life expired.
    Government regulations meant that there was much more money available for renewal than maintenance.
    The Duke chassis was "rather flimsy and fanciful" in design.
    The first conversion happened almost by accident, because the tired out Duke was in the shop on the next pit to Bulldog 3365, and Cook hadthe bright idea of aking one good locomootive out of two.
     
  14. Kerosene Castle

    Kerosene Castle Well-Known Member

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    The Dukes and Bulldogs were all built as slide valve engines; they began getting piston valve blocks around around the start of WWI.
     
  15. ady

    ady Well-Known Member

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    As they a matter of intreset what is a 'Dukedog' like to drive and fire? Effecent steamer? What sort of loads can she handle? Easy to service? etc. etc.

    I sure drivers from Llangollen, Severn Valley and of course the Bluebell Railway can answer that one. 10 points to someone who worked on them in the 'old' days...
     
  16. hassell_a

    hassell_a Member

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    In my whole one day's experience, I'd descibe it as a joy to drive and fire - this was after the valve and piston job on it, mind. Certainly pulling away, care was needed due to only the 4 coupled wheels, but once the train was moving she trotted beautifully, like a turbocharged 57xx :)

    She steamed about as well as any Western engine handled correctly - very freely!

    Takes a fair bit of oil to prep her - those old style axleboxes with the lid covering the trimmings are not the most efficient. And the regulator lubribrictor on top of the dome is 'interesting'...

    In terms of loads, 6 coaches was the agreed limit on the SVR. The main risk being loss of adhesion tender 1st on places like Highley bank - re-instating the tender sanders would help in this respect.

    Over to the Bluebell or Llan guys for their verdict now....
     

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