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Current and Proposed New-Builds

Discussion in 'Steam Traction' started by aron33, Aug 15, 2017.

  1. Monkey Magic

    Monkey Magic Part of the furniture

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    The flipside is how long does the restoration of a Barry wreck take these days? There are also plenty of locos that ran in the 1970s, 80s and 90s and haven't steamed since either.

    While under cover storage ought to be a priority that doesn't mean that people going to pony up the cash for it and it doesn't necessarily mean that a new build or even a restoration project is taking money away from it.

    I'd also suggest that new building is reacquiring and the relearning of lost skills and knowledge and once that is gained a critical mass emerges. Learning points - not just the technical stuff, but knowledge about fund raising, project management, sourcing and so on. Now, the project you are involved with has had some set backs, there are very clear learning experiences from that and looking at the recent posting on the F5 for example it is very clear that they are on it.

    The P2 is clearly progressing faster than the A1 did because they have experience, the Ffestiniog new builds to the outside eye seem to progress faster with each one. (I believe that in the last 40 or so years they have or will have turned out 5 new builds)
     
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  2. Eightpot

    Eightpot Well-Known Member Friend

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    Just taking the last paragraph. The GA drawing for 2001 shows that the clearances for side play on the coupled axles are pretty well minimal. To increase these, amongst other things, a re-design of the cylinder block with wider spaced piston rod centres would be required. As it was the P2s really pushed the boundaries of the LNER load gauge to the limit, and without increases of axle side play any fitting of a Krauss-Helmholtz (or Zara) pony truck would be pointless.

    The original swing link pony truck lasted from the time of the LNER K1 of 1912 to the time of the 1946/7 derailments of V2s at Hatfield and Marshmoor - albeit with a look back at the earlier Thirsk and another incidents.

    I think it was L. D. Porta who once said something along the lines of "Better to have tried and failed, than doing nothing at all." I feel that Gresley and the P2s come into this category.
     
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  3. Eightpot

    Eightpot Well-Known Member Friend

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    Part of the low mileage problem was that the P2s were confined to a section of line only 130 miles long, and at times only worked to the roughly half-way point at Dundee, thus hanging about a lot of the time. There was little point in trying to get the mileage up by using a big powerful loco on intermediate light-weight trains that could be easily hauled by a 4-4-0. After all, the intention was for them to haul heavy trains and if the traffic pattern didn't permit greater use of them it was hardly the fault of the designer.
     
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  4. 30854

    30854 Resident of Nat Pres

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    Excellent points, though I do wonder how the finances of inefficient use of the P2s stacks up against the sort of light engine movements needed to ensure any working is (nearly) always provided with the most suitable motive power.

    BR(S) is often cited as an example, where WC/BB locos were to be found hauling short trains west of Exeter. Did it make more financial sense to use 'overpowered' locos, in preference to keeping smaller (and underutilised) locos to hand? Clearly, any answer has to take account of numerous variables and what made sense west of Exeter may not have done so in the Highlands
     
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  5. LMS2968

    LMS2968 Part of the furniture

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    Same on the LMS and BR (LMR and ScR) with the Stanier Pacifics, which had regular local passenger turns between Crewe and Shrewsbury (which also allowed them to turn on the triangle; Crewe North's turntable for many years was only 60 ft!) and between Glasgow and Edinburgh. It was more productive than having them sit on shed for many hours between turns, and having to find a smaller loco from some where to cover the diagram.
     
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  6. 30854

    30854 Resident of Nat Pres

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    Short ex-LBSC turntables caused operational issues too, which is the reason N15s allocated to the SR 'central division' were supplied with 6w tenders. Thinking about it, when it comes to using 'overpowered' locos, there's an occasionally expressed view that Lawson Billinton's (sadly extinct) K class 2-6-0s only demonstrated their full potential under wartime conditions.
     
  7. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    That didn't seem to be an issue for the Gresley A3s, A4s, W1 or the later Thompson Pacifics which had exactly the same timetabled runs and replaced the P2s on these turns.

    I would suggest that the idea they were under utilised, thus resulting in poorer mileages, to be something of a red herring. If that was the case, and the Pacifics were doing the same job and also doing other work in addition, then the argument for the P2s disappears entirely.
     
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  8. MellishR

    MellishR Part of the furniture Friend

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    The other locos had better availability, leading to better mileages, but was that just on average or did it apply even to those working the Aberdeen road?
     
  9. 242A1

    242A1 Well-Known Member

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    These figures might be of interest.


    Maximum loads for Class P2 with A3 loads in brackets.

    Tons(tare)
    Edinburgh - Glasgow 550 (500)
    Glasgow - Edinburgh 550 (500)

    Edinburgh - Perth 500 (450)
    Perth - Edinburgh 475 (425)

    Edinburgh - Aberdeen 530 (480)
    Aberdeen - Edinburgh 530 (420)

    Dundee - Edinburgh 550 (425) Assisted to Forth Bridge North if stopped at Inverkeithing.
     
  10. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    Example stats for your analysis.

    upload_2021-10-20_16-33-49.png

    upload_2021-10-20_16-35-13.png

    Note the Scottish examples.
     
  11. Eightpot

    Eightpot Well-Known Member Friend

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    If that was the case with Pacfics able to do the job, one is just left wondering as to who, and with what justification, managed to get the order given to build the P2s in the first place when existing locos were supposedly capable of meeting the requirement. Bearing in mind the financial constraints the the LNER operated under, a pretty good case to have them built must have been made.
     
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  12. S.A.C. Martin

    S.A.C. Martin Part of the furniture

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    There's no "supposedly" about it. It's factual, borne out by the records we have. It remains factual that the duties of the Mikados was taken on by similarly sized and similarly powerful Pacifics in WW2 and were then replaced outright by Pacifics from Gresley, Thompson and Peppercorn for the rest of the lifetime of the LNER and the nationalised company which came after. The fact that the A2/2s, A2/3s and the Peppercorn A2s were all allowed to do the same stipulated maximum as the P2s says much about their abilities to do the work required, and that the P2s advantages didn't translate necessarily into good financial return for the company.
     
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  13. 30854

    30854 Resident of Nat Pres

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    Honestly don't know how much it affects this particular question, but having just checked axleloads of the P2 vs (Peppercorn) A2, it's recorded as a full 2t lighter.

    Enquiry: What classed were used on the Aberdeen line before the P2s were introduced?
     
  14. Cartman

    Cartman Member

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    NB Reid Atlantic's and various types of 4-4-0s at a guess
     
  15. Jamessquared

    Jamessquared Nat Pres stalwart

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    I think it absolutely did make sense.

    For example, one of the turns often noted: a one coach Padstow to Wadebridge working. The loco had started from Exeter, probably with about 9 coaches; dropped three off at Halwill Junction and arrived at Padstow with 6. The turntable there was too short to turn the pacific, so it worked back to Wadebridge for overnight servicing and turning, taking a carriage to form an evening service. I doubt the fireman threw a single shovelful on from arrival at Padstow to going on shed at Wadebridge - instead, just letting the fire run down. If you think of the alternative, the loco would have to run the miles from Padstow to Wadebridge anyway for servicing, so if it didn;t pull that train, you still had the loco miles but no service, or would have to specially steam a loco just to run it.

    Another example was the two coach Cuckoo Line job: the loco worked down on an Eastbourne train in the morning, and had an afternoon service back, but ran a short branch train to fill in - the alternative would be the loco just sitting around while another loco covered the turn.

    Diagramming is rarely appreciated, but is the key to economy. If you have a loco available in steam and otherwise unused, it is almost invariably your cheapest option for running a train, even if it is too powerful for the load on offer. And a big loco on a light load doesn't necessarily burn much more coal than a smaller loco on the same load: after all, it is doing basically he same work, so why should it?

    That's not an argument for building locos much bigger than you need, but is an argument for using the available loco in preference to steaming another.

    Tom
     
  16. Allegheny

    Allegheny Member

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    It will be interesting to see how the new P2 performs in comparison with pacifics, in particular Blue Peter.
     
  17. 61624

    61624 Well-Known Member

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    It's a myth that there are numerous ex-Barry engines yet to be steamed - there's about a quarter left and many of those being actively worked on with a genuine prospect of being steamed in the foreseeable future It's true that many have re-entered a period of dormancy but are increasingly being stored under cover and treated as museum pieces. What is happening is that new builds are both benefitting from existing spares and pattern pools and also contributing to keeping existing locos running (e.g. 2007 and the N2 sharing a wheel pattern) and that has to be a good thing. I don't think we'll ever see numerous new builds but it is good to see glaring gaps in the range of what there is plugged.
     
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  18. MellishR

    MellishR Part of the furniture Friend

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    Thank you for that.

    Judged by availability, the A1s, which were the oldest, were the best, apart from the GN area A4s, with the Scottish area A1s being best of all. Maybe they were allocated to lighter duties than the newer locos, so had an easier life. But only 4 of them so perhaps not statistically significant.

    A3s much the same in all areas.

    Less difference in Scotland between the P2s and the A4s than between the A4s and the A1s. P2s worse than all the Pacifics but not much worse than the A4s in Scotland.
     
  19. Bikermike

    Bikermike Member

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    Part of it is also standardisation surely?

    What is the cost/benefit point with using a light pacific to fill in between big turns allowing you to scrap an antediluvian 4-4-0 and cut back spares inventories etc?

    On national rail now, you now see 66s pulling water-jetting trains (2 wagons and another 66 on the back), rather than use a smaller engine.
     
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  20. class8mikado

    class8mikado Well-Known Member

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    'It will be interesting to see how the new P2 performs in comparison with pacifics, in particular Blue Peter'


    It will and to my mind prove that the love we had here for the Pacific wheel arrangement was misplaced.
    Given the almost identical boiler, grate area, draughting and wheel size the only significant differences are the Cylinders/ valve gear/ factor of adhesion.
    Making some generalisations about those; P2 Valve performance at lower speed may not be as 'strong' as walshaerts but with slightly larger cylinders and better adhesion starting and acceleration will be very strong and more reliable than anything else we have, maybe even a King.
    Once in its stride the efficiency of the valve gear gives you a loco that, at full regulator and low cut offs will still be running away with itself even with 13 on on anything less than a stiff gradient

    Just like the King i think the Cylinder size has been chosen to ensure that PofW tops the TE chart and are actually bigger than required...
     

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