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.

FR & WHR & WHHR News

Discussion in 'Narrow Gauge Railways' started by AndrewT, Jul 17, 2012.

  1. 30854

    30854 Resident of Nat Pres

    Joined:
    Mar 8, 2017
    Messages:
    12,172
    Likes Received:
    11,493
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Brighton&Hove
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Just watched "Moving Pictures No.31" .... most enjoyable, but a (possibly daft) question .....

    Looking at the L&B powered half of 'The Snowdonian", the exhaust on 'Lyn' is virtually invisible, when compared with 'Lyd'. Is this a result of a higher exhaust temperature, or merely a result of improved use of steam ('Lyn's' economic use of water has been commented upon, during it's Snowdonian sojourn)?
     
  2. michaelh

    michaelh Part of the furniture

    Joined:
    Apr 29, 2006
    Messages:
    3,080
    Likes Received:
    1,291
    Gender:
    Male
    Occupation:
    Very comfortably early retired
    Location:
    1029
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Is Lyn superheated?
     
  3. 30854

    30854 Resident of Nat Pres

    Joined:
    Mar 8, 2017
    Messages:
    12,172
    Likes Received:
    11,493
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Brighton&Hove
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Yep ..... isn't Lyd?
     
  4. 8126

    8126 Member

    Joined:
    Mar 17, 2014
    Messages:
    823
    Likes Received:
    962
    Gender:
    Male
    I believe the FR engines are generally fitted with quite a low degree of superheat. I've just checked, and there are 2 flues per barrel for a double Fairlie (except DLG, which I think has more), while Lyd has 8 flues in its single barrel. If you're retrofitting superheat to slide-valved engines, low degree superheat is generally considered sensible, although I suspect in later LNER years quite high-superheat boilers ended up on Ivatt Atlantics which had not received piston valve conversions.

    Lyn, on the other hand, is a piston valve engine and was designed as such from the outset. She has eleven flues, so to a first order approximation will have a considerably higher degree of superheat. This carries through to exhaust temperature. Notched up, this might not make so much difference, but working hard at medium cut-offs and large regulator openings, the exhaust will be a lot less visible. I remember seeing videos of SAR 25NCs working hard in the cold Karoo. The exhaust would be invisible, until it suddenly appeared in a giant plume a few feet above the chimney.

    *Edited to reflect actually taking the time to check my numbers.
     
    Last edited: May 6, 2019
    MattA and Sheff like this.
  5. 30854

    30854 Resident of Nat Pres

    Joined:
    Mar 8, 2017
    Messages:
    12,172
    Likes Received:
    11,493
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Brighton&Hove
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Many thanks for a comprehensive explanation .... I did originally say it was possibly a daft question! :)

    Thinking back, I do seem to recall a shot of Lyd's front tube plate during construction and recognise your description from that. A quick shuftie at Lyn's construction pages confirmed the degree of superheat applied.

    From various sources concerning it's visit to the FR/WHR t'would appear Lyn's performance has impressed folk all round. It certainly looked the part in all the clips and stills I've seen .... especially (IMHO) as it wasn't spewing the filth beloved of too many photographic types!
     
    Sheff likes this.
  6. Jamessquared

    Jamessquared Nat Pres stalwart

    Joined:
    Mar 8, 2008
    Messages:
    26,100
    Likes Received:
    57,416
    Location:
    LBSC 215
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Likewise the Brighton Atlantics (H1 - originally saturated and slide valve and H2 - originally superheated and piston valve) which by the end of their lives were all fitted with superheated boilers, with 32 flue tubes (4 rows * 8 flues). I suspect lubricant technology developed considerably between, say, 1910 and 1950; no doubt the two wars and the need for high performance aero engines acted as a spur to innovation in lubricant technology.

    Tom
     
    30854 and Sheff like this.
  7. weltrol

    weltrol Part of the furniture Friend

    Joined:
    Dec 29, 2008
    Messages:
    2,784
    Likes Received:
    658
    Looking at recent photos and videos of 'Lyn', the loading gauge seems very close to that of the FR . Would 'Lyn' actually be capable of traversing the whole FR, or would Garnedd Tunnel be the pinch point?

    Frank N.
     
  8. meeee

    meeee Member

    Joined:
    Mar 28, 2006
    Messages:
    864
    Likes Received:
    1,319
    Lyd doesn't have much superheat really. They aren't the same design as the other FR locos with an out and back loop on each element. They consist of a tube within another tube. So there is less surface area per element. They were also shortened over the winter because of cracking.

    Tim
     
  9. 30854

    30854 Resident of Nat Pres

    Joined:
    Mar 8, 2017
    Messages:
    12,172
    Likes Received:
    11,493
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Brighton&Hove
    Heritage Railway Volunteer:
    No I do not currently volunteer
    T'will be interesting to see how knowledge gained during the two (rather spledid) L&B recreations will translate into the design stage for the planned next pair.of MWs.

    (Part of me is still half wondering whether future L&B requirements might tempt 'em to build 'County Gate's' 009 2-6-6-2t Mallets for real .... note running number!
    54m.jpg.cf.jpg
    Image from www.009.cd2.com and well worth a butcher's!)
     
    MattA and andrewshimmin like this.
  10. Jamessquared

    Jamessquared Nat Pres stalwart

    Joined:
    Mar 8, 2008
    Messages:
    26,100
    Likes Received:
    57,416
    Location:
    LBSC 215
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Quite an entertaining model but I have a nagging doubt that that boiler wouldn’t keep pace with all those the cylinders! (And where is the ashpan supposed to sit? :eek:)

    Tom
     
  11. 30854

    30854 Resident of Nat Pres

    Joined:
    Mar 8, 2017
    Messages:
    12,172
    Likes Received:
    11,493
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Brighton&Hove
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Gas fired compound perhaps? :Bag:
     
  12. 8126

    8126 Member

    Joined:
    Mar 17, 2014
    Messages:
    823
    Likes Received:
    962
    Gender:
    Male
    Oh, that is interesting, so coaxial superheaters like you find in some models (except those tend to be in stainless and extend into the firebox)? The other downside of those is no matter which way you arrange it, you end up having the hot return flow losing heat to the cool incoming steam. So Lyn is likely to have a really quite significant advantage in steam temperature, which probably explains the notably good water consumption previously commented on.
     
  13. andrewshimmin

    andrewshimmin Well-Known Member

    Joined:
    Mar 18, 2011
    Messages:
    1,761
    Likes Received:
    2,160
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Tom,
    Firstly, you're no fun any more...
    Secondly, presumably these guys have ash pans? https://upload.wikimedia.org/wikipe...emin_de_fer_du_Vivarais_à_Tournon_en_1978.jpg
    Thirdly, you don't need to worry about ash it you follow the prototype and simply fit a really big can motors where the boiler should be ...
     
    Sheff, MattA, clam1952 and 3 others like this.
  14. meeee

    meeee Member

    Joined:
    Mar 28, 2006
    Messages:
    864
    Likes Received:
    1,319
    If it's working a heavy train on a decent run yes. I expect on 1 mile of L&B the loco will be quite wet because the superheaters don't have time to start working. You could have an endless debate on if the extra cost of superheating is really worth it on railways where you stop every 2 miles.

    Tim
     
  15. Paul.Uni

    Paul.Uni Well-Known Member

    Joined:
    Aug 28, 2008
    Messages:
    1,284
    Likes Received:
    583
    WHR event booking form and timetable teasers: https://www.festrail.co.uk/content/uploads/1/WHR-PPF_Booking_Form_v2_1.pdf

    Details and how to book for the solo Russell trips to Beddgelert: https://www.facebook.com/WHHRly/posts/2718600661515762 Relevant info in quote below for those who don't do FB
     
    Last edited: May 8, 2019
    black5 likes this.
  16. marshall5

    marshall5 Well-Known Member

    Joined:
    Oct 26, 2010
    Messages:
    2,375
    Likes Received:
    3,981
    Location:
    i.o.m
    Heritage Railway Volunteer:
    Yes I am an active volunteer
  17. jon5051

    jon5051 Member

    Joined:
    Jun 20, 2006
    Messages:
    669
    Likes Received:
    380
    Location:
    Bucks
    Heritage Railway Volunteer:
    No I do not currently volunteer
  18. jamesd

    jamesd Member

    Joined:
    Aug 24, 2009
    Messages:
    598
    Likes Received:
    302
    Location:
    S Wales
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Wow!! It doesn’t cover the whole WHR either - from the website:
    “Can be used during all three days for travel on all RhE • WHR trains between Porthmadog and Beddgelert, on event trains between Porthmadog and Boston Lodge and on all WHHR public trains.”
     
  19. 8126

    8126 Member

    Joined:
    Mar 17, 2014
    Messages:
    823
    Likes Received:
    962
    Gender:
    Male
    I think with superheat, if you want it to work on short runs, there's no point just tickling it. You need a lot to get the benefits quickly, since the superheater is going to get up to operating temperature in much the same time no matter how many flues worth you have, whereas the hotter the steam the faster the cylinders (which are the real thermal lag in the system) warm up. Lighter cylinders help here, I wouldn't be surprised if the Lyn's fabricated cylinders are also an advantage. Sentinels are obviously quite an extreme manifestation of this approach.

    The Ffestiniog, with its long steady uphill from one end of the line to the other, is probably one of the few preserved lines where low superheat still pays off, and the smaller your engine the faster it all comes up to temperature; a 2 foot gauge engine is a very different proposition to a standard gauge engine in this respect.
     
  20. Paul.Uni

    Paul.Uni Well-Known Member

    Joined:
    Aug 28, 2008
    Messages:
    1,284
    Likes Received:
    583
    Sorry about that. It seems they updated the pdf and the link I posted became broken as a result. The post has been updated with the current link.
     
    marshall5 likes this.

Share This Page