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Is a real Bulldog possible ?

Discussion in 'Steam Traction' started by hyboy, Dec 9, 2013.

  1. Jamessquared

    Jamessquared Nat Pres stalwart

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    I had a few trips on 5199 when she visited the Bluebell some years back. My experience was that she was very technique-dependent. If you got a really hot well burnt-through fire before starting, then she would steam OK, on the "little and often" principle of firing thereafter. But if you misjudged things and put the coal on too late before departure, pressure would drop and drop and there was nothing you could do about it. I don't remember what limit we set her - with that TE, there wouldn't have been any problem with ability to shift any conceivable Bluebell load on the gradients, but the sustained steaming ability up about 6-7 miles of nearly continuous 1:75 was definitely suspect. My guess is that we allowed her 6 Mark 1s, but probably rarely ran her with more than 5, which was our normal load in those days anyway.

    Certainly a marked contrast to the U Boat, which may nominally have a much lower TE, but gives far more confidence about being the master of the job! 5199 handled very much like a small engine; 1638 much more like a big engine from a fireman's point of view - at least in my experience.

    I've always thought a lot of GWR locos have very small grate areas relative to the size of the cylinders. They must have got very high horsepower per square foot of grate area from them, presumably on account of having access to very good coal. Either that, or the locos must have been driven well below the theoretical cylinder capacity to allow the boiler to keep pace. It is highly suggestive to my mind that when BR built a Standard version of a 2-6-2T around the same boiler, they put much smaller cylinders on and basically created a Standard 3 tank with that boiler, not a class 5 tank that the 61xx is trying to be.

    Tom
     
  2. Reading General

    Reading General Part of the furniture

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    faulty engine or faulty engineman?
     
  3. MuzTrem

    MuzTrem Member

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    Thanks for bringing that up, as it's something I've more than once heard passing references to, but struggled to find detailed information about!

    I'm sure what we're all dying to know is: does anyone know exactly where they are, what condition they are now in, and whether there is any possibility of raising at least one of them?

    (Failing that, I think it would make a very worthwhile new-build project - a double-framed 0-6-0 tender engine is an enormous gap in British railway preservation. Doubt you could raise the funds, though, since you'd never be able to paint it in BR livery...!)
     
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  4. Jamessquared

    Jamessquared Nat Pres stalwart

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    As I said, "technique dependent". Whether you feel it is the engineman's fault for not having exemplary technique, or the loco designer's fault for building an engine that only works with one very specific technique - I'll leave you to make your own decisions! I know what my feeling is. (Hint: the job of a locomotive designer is to produce a machine that works in real-world conditions…)

    I'm still convinced that, regardless of technique, the boiler on a 61xx is too small for the size of the cylinders.

    Tom
     
  5. david1984

    david1984 Resident of Nat Pres

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    Were the 61XX's not intended for rapid commuter work ?, with frequent stops perhaps sustained output wasn't as big a consideration as smart acceleration and running between said stops ?.

    Would the difference in boiler pressure between the standard 51XX and the 61XX variant make much difference ?, reason I ask is the equivalent of 61XX turns around Birmingham usually had 51XX's or 56XX's.
     
  6. Jimc

    Jimc Part of the furniture

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    After 100 years in salt water I think you'll find it would be a major and expensive exercise just to conserve one sufficiently so that it didn't just disintegrate into a pile of rust within a few years of getting it out on the land. I should have thought the chances of restoring any iron or steel components to anything approaching usable condition would be minimal. The preservation work on HMS Holland 1 might be a guide to what's involved... http://www.submarine-museum.co.uk/what-we-have/our-submarines/holland-1/holland-i-conservation
     
  7. Jimc

    Jimc Part of the furniture

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    I submit that the job of the locomotive department is to run the services the traffic department requires as cheaply as possible.
    If a loco department could maintain a skill level amongst its crews which permitted it to run services with 78 ton locomotives when all the other lines were using 86 and 90 ton ones for the same tasks that might produce worthwhile savings. If the crews were adequately skilled then designing locomotives to run with unskilled crews might not (to use modern business speak) add any value.
     
  8. 1472

    1472 Well-Known Member

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    The experience Tom quotes re 5199 on the BB doesn't sound good - or typical for 51xx/61xx locos.

    4160 on the WSR will comfortably handle 8 Mk1s over the 20 mile line including the 6 mile continuous climb Williton - Crowcombe . Similarly 9351 (rebuilt from 5193 with out the tanks but with 40 odd tons worth of tender) will do the same. Both are close to the maximum doing this but properly fired steam is not an issue.
    4160 does though have double the superheat of the others being fitted with a late modified boiler (similar on 5668).
    5164 on the SVR regularly handles 8 Mk1s also & IIRC has taken 10 before now.
    4144 visited the SVR some years ago & performed similarly to 5164.
    4141 & 5199 have both worked on the SVR but I have no direct experience of them.

    That said every sq ft of the grate needs to be supplying heat and, as on all similar GW locos, a reasonably thick backend ensures that the sharp (lovely!) exhaust does not pull holes in the fire.

    These locos used to work tightly timed suburban services in the London area (61xx) & Birmingham (51xx). In terms of steam requirements these duties with short stops & plenty of vigorous restarts were probably more demanding than cruising along non stop on some of the bigger locos.

    These do need driving fairly hard to get the best out of them & at our HR speeds are not happy notched much higher than about 40% though no doubt would run at 60mph on shorter cut offs with ease if permitted on NR.
     
  9. Jamessquared

    Jamessquared Nat Pres stalwart

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    As I say, that was just my experience - other people's may differ. I think I had about four or five days on her over the course of a year, so maybe more familiarity would have bred more confidence. It does seem on all the GW locos I have been on that they respond best when driven hard - if the driver is too cautious, the fireman will struggle. But certainly if you ever went on a U Boat, you'd never want to go back on a GWR prairie again… :)

    Tom
     
  10. LesterBrown

    LesterBrown Member

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    I've never really understood the BR (ex LMS etc.) power classifications. He is it that the little 4500 (21250 lb TE, 16.8 sq ft grate) were classified 4MT the same as the big 3100 class of 1938 (31170 lb TE, 20.6 sq ft grate)?

    Presumably after a quarter of a century's experience the no 2 boiler was judged quite adequate for London suburban work when the 6100s were ordered; weight wouldn't have been an issue on those duties replacing the County Tanks with 19 tons axle loading!

    Sent from my HTC One mini using Tapatalk
     
  11. Martin Perry

    Martin Perry Nat Pres stalwart Staff Member Moderator Friend

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    I get the feeling that Swindon didn't really understand them either :)
     
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  12. Jamessquared

    Jamessquared Nat Pres stalwart

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    Because someone at Swindon was having a laugh at Derby's expense...

    The Midland-style power classifications were only applied to non-LMS locos after nationalisation. My understanding is that Derby sent out a kind of specification of how to work out the classifications, but then allowed each region to get on with classifying their own locos. I reckon Swindon thought they'd show those northerners a thing or two by pretending a loco as small as a 45xx was really a class 4… To a large degree I suspect it was really an accounting exercise, so the newly formed BR could at least get a rough comparison for statistical purposes of how many locos they had in different power classifications.

    In practical terms it wouldn't actually matter very much, all the time pre-BR locos stayed largely on their own home territory. Shed masters would have a pretty good idea what locos of different types could handle relative to the local terrain they had to cover, and in any case, if the Southern is any guide, the sectional appendices that covered maximum loadings for each route were written with specific classes, rather than power classifications. So, for example, the appendix for e.g. Barnstaple - Ilfracombe gave loadings for N class mogul, U class mogul, M7, WC/BB, GWR 43xx etc without paying much attention to what the supposed power rating was. It only became a problem when a loco went off home turf. I would wonder what a shed master away from BR(W), used to a diet of 80xxx tanks, would think when promised a supposed replacement 4MT loco by Swindon and discovering that a 45xx had turned up...

    Tom
     
  13. Jamessquared

    Jamessquared Nat Pres stalwart

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    Addendum to the above: These are the allowed loadings from Ilfracombe to Mortehoe & Woolacombe (about 2 miles of 1:36 starting from the platform end at Ilfracombe) for various classes of engine, as laid out in the appropriate BR sectional appendix.

    WC/BB (unrebuilt) - 205 tons

    Maunsell N class - 180 tons
    GWR 63xx - 180 tons

    Drummond M7 - 140 tons
    London Midland 2MT 2-6-2T - 140 tons
    GWR 45xx - 140 tons

    GWR 22xx - 110 tons
    Drummond T9 - 100 tons

    In other words, ignore the power classifications. In practical terms, a 45xx (supposedly 4MT) was rated the same as a Drummond M7 (2P) or an Ivatt class 2MT tank.

    Tom
     
  14. 1472

    1472 Well-Known Member

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    Tom - maybe - but straight comparing a 45xx with a 80xxx is something of a nonsense - they are for different purposes. Similarly you wouldn't put a an Ivatt Cl 2 tank on the same work as a LM 4-4-0 2p - again they are for different duties.

    If you want a fast exceptionally smooth riding mainline loco the 80xxx is the one without doubt.

    If you want to move quite heavy loads on sharply curved steep gradients then the 45xx scores over the 80xxx every time.

    It is quite possible to slip to a stand with an 80xxx due to the length of wheelbase on uneven track - much less likely with a 45xx as it will dig in and get on with the job.
     
  15. Steve

    Steve Resident of Nat Pres Friend

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    I think that, in simple terms, the GW lot couldn't understand the Midland power classification and that's probably true of most people! If Wikipedia is anything to go by, it is based on T.E. at specific speeds. ( http://en.wikipedia.org/wiki/Power_classification#LMS_System )

    My experience of GW locos is basically limited to 4277, 5229 & 6619 but I have a lot of experience with the latter two and 6619, in particular. They had no problem in producing the steam required and the 2-8-0's were master of the routine task of 7 coaches on the NYMR's 1 in 49. 6619, however, was always a 12 mph plod on the bank in its last term when it had spec wheel and cylinder diameters and I could never understand its class 5 power classification.. Even if you got it moving before hitting the gradient, it would fall back to this balancing speed, even with the feather showing, and keep going at this without any problem. I've stopped on the 1 in 49 twice with it and re-starting wasn't a problem so it was certainly sure footed and had the necessary starting tractive effort.

    As with most things GW, it was probably more down to their very good propoganda machine than the reality.
     
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  16. Jamessquared

    Jamessquared Nat Pres stalwart

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    Yes, but somebody at head office obviously thought a 45xx and an 80xxx were comparable, because both were rated 4MT. If there was a purpose to assigning power classifications to locos, presumably it was to give a degree of comparability in likely performance on certain types of duties between locos of different types.

    I take the point about "horses for courses", but it's not like even like comparing a 4F with a 4P (or in your example a 2MT with a 2P) - someone thought they were both, notionally, equivalent. Whereas the more practical view on the ground was that a 45xx 2-6-2T was much more comparable with an Ivatt 2-6-2T - which sounds a lot more plausible!

    My point is - if you want to compare locos, treat the numbers with caution and look at the duties they were assigned back in the day...

    Tom
     
  17. Jimc

    Jimc Part of the furniture

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    Don't think you can say that at all. The Kremlin produced a set of calculations which were duly applied and recorded, and reported back. Nothing to do with the WR staff if the calculations didn't produce very sensible results, and in any case the WR carried on using their existing system which did work for them. I've also seen references that suggest that in practice the Southern carried on using their old system because the LMS one wasn't useful for them either.
     
  18. paulhitch

    paulhitch Guest

    Put a No. 2 boiler onto an M7 and the result would be a Bulldog Drummond I suppose.

    Paul H.
     
  19. Jamessquared

    Jamessquared Nat Pres stalwart

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    Some of the participants on this thread will be ringing up Swanage "to make enquiries" even as we speak...

    Tom
     
  20. Nigel Clark

    Nigel Clark Member Loco Owner

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    In my experience the Swindon No.2 boiler generally steams exceptionally well and will usually steam against the Fireman's side 8mm injector running virtually continuously, but all engines need to be correctly fired (and driven) to make them steam and to get the best out of them. I have fired 4160 on several occasions with 9 Mk.1s which she has handled comfortably, the boiler easily keeps up with the demands of the cylinders if the loco is driven properly. 9351 would similarly steam very freely, and would load to equal 9 (8 + the tender). 6695 has also handled 8 and 9 coaches over the WSR without issue. Crew familiarity can have a very big effect on loco performance, but there are many other factors too such as valve settings and wear in the bores and rings, blocked tubes, ashpans solid with ash etc. The art is to get the firebed hot before you start away.
     

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