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.

Things that seemed a good idea at the time, but in practice are pretty useless.

Discussion in 'Steam Traction' started by Eightpot, Oct 3, 2019.

  1. Dunfanaghy Road

    Dunfanaghy Road New Member

    Joined:
    Oct 9, 2019
    Messages:
    32
    Likes Received:
    41
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Alton, Hants
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    I recently read in Bradley that Mr. Drummond's F13 4-6-0s (F for fiasco?) had different throw cranks. I suppose that after so many bad ideas, why not add one more.
    Pat
     
  2. bluetrain

    bluetrain New Member

    Joined:
    Mar 3, 2019
    Messages:
    118
    Likes Received:
    148
    Gender:
    Male
    Location:
    Wiltshire
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Here is what the railway author EL Ahrons had to say on the subject in 1925:

    "Piston tail rods, after having been tried by Adams for some years on the L&SWR, were discarded on this line about 1896, and were adopted at about the same time by the NER. The reason then given, alike for their adoption and disuse, was exactly the same in each case, namely that the opposite course was productive of wear and scoring of the cylinders. Apparently the question is still sub judice, although the tail rods tend to disappear, partly owing to the increase of the reciprocating masses which they involve."

    I suspect that the issue of reciprocating mass was the clinching argument that decided British engineers in the 1920s against continuing with tail rods. They would have become much more conscious of this factor as a result of research during that decade by the "Bridge Stress Committee".

    Overseas, tail rods also seemed to fall out of favour in USA and Canada, and at a later date in Soviet Union. France seemed to be 50:50 - some engines had them and some didn't. But in Germany and other Central European countries, tail rods became seen as essential items and were fitted to virtually all steam engines, continuing with them in the preservation era.
     
  3. MellishR

    MellishR Well-Known Member Friend

    Joined:
    Apr 16, 2009
    Messages:
    4,333
    Likes Received:
    2,007
    I suspect that whether a tail rod increases or reduces wear in cylinders depends on how accurately or otherwise everything is aligned. I am dubious about the reciprocating mass argument: surely the mass of a tail rod is very small compared to the masses of the piston, piston rod and connecting rod.
     
    jnc likes this.
  4. LMS2968

    LMS2968 Well-Known Member

    Joined:
    Sep 1, 2006
    Messages:
    2,125
    Likes Received:
    2,099
    Gender:
    Male
    Occupation:
    Lecturer retired: Archivist of Stanier Mogul Fund
    Location:
    Wigan
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Agreed, and as the tail rod is not transmitting piston forces but merely carrying the weight of the piston, it can be made a smaller diameter than the piston rod.
     
    andrewshimmin likes this.
  5. Jamessquared

    Jamessquared Nat Pres stalwart

    Joined:
    Mar 8, 2008
    Messages:
    16,617
    Likes Received:
    24,626
    Location:
    21C102
    I’ve often wondered if the additional costs of making and maintaining an additional gland also came into it.

    I suspect in practice the advantages were probably finely balanced and simultaneous developments around that era in better lubrication, more and better piston rings and so on may have been sufficient to swing the supposed advantage one way or another. Perhaps pertinent in the discussion about Adams that as well as piston tail rods, he also preferred single slide bars on his outside cylinder locos - so maybe just had a different conception about how best the weight of the whole piston / rod / cross head should be supported over its length.

    Tom
     
    andrewshimmin, bluetrain and jnc like this.
  6. Dunfanaghy Road

    Dunfanaghy Road New Member

    Joined:
    Oct 9, 2019
    Messages:
    32
    Likes Received:
    41
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Alton, Hants
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Certainly the German engines have a large bush on the front cylinder cover. I assume that this allows adjustment to carry the weight of the tail rod properly, no point in it otherwise.
    Pat
     
  7. Hermod

    Hermod New Member

    Joined:
    May 6, 2017
    Messages:
    561
    Likes Received:
    136
    Gender:
    Male
    Location:
    Klitmoeller,Denmark
    Heritage Railway Volunteer:
    No I do not currently volunteer
    It was tested on five german BR50 locomotives to omit tailrod.
    After 7000 km they measured up to three mm wear and after 70000m they put tailrods on.
    BR50 (and52) had single slide bars like Adams and it was stated that this could have been a reason for failure of experiment.
    The LNER Tornado pistons has a cast bronce ring carrier on piston and I wonder if that was normal on british pistons without tail rods.
    The germans had to be very frugal with bronze or brass due to lack of cupper.
     
    bluetrain likes this.
  8. 240P15

    240P15 Member

    Joined:
    Dec 1, 2017
    Messages:
    1,052
    Likes Received:
    905
    Gender:
    Male
    Location:
    Norway
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Bluenosejohn and bluetrain like this.
  9. Steve

    Steve Part of the furniture Friend

    Joined:
    Oct 7, 2006
    Messages:
    9,304
    Likes Received:
    4,577
    Occupation:
    Gentleman of leisure, nowadays
    Location:
    Near Leeds
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    BR Standards originally had a bronze carrier for the piston. I'm not sure whether these were abandoned, or not. No doubt Stdtank can say. Picture1.jpg

    [​IMG]
     
    Last edited: Nov 18, 2019
    240P15, RLinkinS and jnc like this.
  10. LesterBrown

    LesterBrown Member

    Joined:
    Jan 20, 2009
    Messages:
    836
    Likes Received:
    573
    Location:
    Devon
    Most British lines developed outside cylinder locos after many decades of building inside cylinders locos where there wasn't usually space for tail-rods anyway. Presumably many engineers just didn't see the need to add them when larger locos led to more use of outside cylinders.
     
    240P15 likes this.
  11. andrewtoplis

    andrewtoplis Member

    Joined:
    Mar 28, 2006
    Messages:
    980
    Likes Received:
    295
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    I'm getting a bit off topic, but could we add round spectacle plates? Why British Victorian designers persisted with tiny round windows when the Americans had much bigger, square ones is anyone's guess...
     
    jnc likes this.
  12. ross

    ross Member

    Joined:
    May 18, 2017
    Messages:
    410
    Likes Received:
    768
    Gender:
    Male
    Location:
    Titfield
    Heritage Railway Volunteer:
    No I do not currently volunteer
    On early American locomotives the steam chests were lubricated with tallow, from a long spouted pot which was kept hot on a shelf over the firedoor. The fireman was required, at the behest of the engineer, to walk out on the running boards and lubricate these steam chests on the move. Whether this was because tallow is a poorer lubricant than the British had, or whether it is because of greater distances between stops I do not know. Locomotive cabs were generally of wooden construction, with large doors on either side at the front to allow said fireman to get out onto the running board. In very hot weather locomotives would run with these doors open for ventilation. Large rectangular doors allowed for large rectangular cab front windows which became the norm from 1840's onward.
    The visibility aspect seems largely irrelevant as American engineers, always drove with their head out the side window of the cab come rain, sleet, hail or snow .
     
  13. Forestpines

    Forestpines Well-Known Member

    Joined:
    Jun 5, 2009
    Messages:
    1,419
    Likes Received:
    1,798
    Location:
    Bristol
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    My understanding was that both the use of tallow for cylinder lubrication and the requirement to lubricate from the running plate whilst on the move were both standard early British practice too
     
    LMS2968 and Jamessquared like this.
  14. LMS2968

    LMS2968 Well-Known Member

    Joined:
    Sep 1, 2006
    Messages:
    2,125
    Likes Received:
    2,099
    Gender:
    Male
    Occupation:
    Lecturer retired: Archivist of Stanier Mogul Fund
    Location:
    Wigan
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    In Britain, it was the driver who would sally forth along the running plate to add oil as he felt necessary. The L&YR Atlantics also had full height doors each side of the spectacle plate.
     
    andrewshimmin and Forestpines like this.
  15. Jamessquared

    Jamessquared Nat Pres stalwart

    Joined:
    Mar 8, 2008
    Messages:
    16,617
    Likes Received:
    24,626
    Location:
    21C102
    Just on the point of large cab windows rather than portholes in Victorian locos - Adams was rather partial to them (look at photos of the Adams radial tank, for instance).

    Tom
     
    andrewshimmin and Wenlock like this.
  16. Jamessquared

    Jamessquared Nat Pres stalwart

    Joined:
    Mar 8, 2008
    Messages:
    16,617
    Likes Received:
    24,626
    Location:
    21C102
    Wasn’t the Ais Gill crash at least partly attributable to the driver spending time on the frames oiling the loco while the fireman struggled with a recalcitrant injector, with the result they were distracted from the view ahead? I seem to recall the loco concerned had better lubrication with no necessity to go round that way, but the driver was somewhat old school and carried it out just because that was what he had always done.

    Tom
     
    jnc likes this.
  17. LMS2968

    LMS2968 Well-Known Member

    Joined:
    Sep 1, 2006
    Messages:
    2,125
    Likes Received:
    2,099
    Gender:
    Male
    Occupation:
    Lecturer retired: Archivist of Stanier Mogul Fund
    Location:
    Wigan
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    Indeed, that was how it happened.
     
    andrewshimmin likes this.
  18. GWR4707

    GWR4707 Resident of Nat Pres

    Joined:
    May 12, 2006
    Messages:
    11,448
    Likes Received:
    7,530
    Gender:
    Male
    Location:
    Cumbria
    Heritage Railway Volunteer:
    No I do not currently volunteer
    Was pretty standard practice I believe.

    When my old man worked inside at Swindon he used to occasionally manage to blag a ride on a locomotive on a running in turn from the works. The only time he ever rode on a King (6008) she was running with a crane to somewhere west of Swindon, running round and then coming back. The run westwards was tender first and apparently the weather was dreadful in torrential rain, the fireman and inspector walked along the running plate and stood on in front of the smokebox on the run to keep dryer, leaving only my old man (who was told not to as he wasn't actually supposed to be there) and the driver to get wet on the footplate.

    Apparently the run back chimney first was very lively as the driver basically pushed the regulator up to the cab roof and she took off like a scalded cat.
     
    Bluenosejohn and Mr Valentine like this.
  19. LesterBrown

    LesterBrown Member

    Joined:
    Jan 20, 2009
    Messages:
    836
    Likes Received:
    573
    Location:
    Devon
    My thoughts are that it was probably originally simpler to mount circular rather than square cornered glass in a vibrating iron spectacle plate without risk of it shattering. Windows in American wooden cabs were more akin to carriage windows.
     
    andrewshimmin likes this.
  20. Mr Valentine

    Mr Valentine Member

    Joined:
    Mar 9, 2018
    Messages:
    90
    Likes Received:
    267
    Gender:
    Male
    Location:
    Titfield
    Heritage Railway Volunteer:
    Yes I am an active volunteer
    On the GWR around the turn of the century, some 4-4-0's, and possibly other types, had doors in the front cab sheet to allow access to the running plate. Somewhere I have a great MIC book written by a GWR engineman in the 1890's, which describes how to attend to a crosshead running hot whilst the engine is still running. Mind you, other 'advice' includes running the engine 'sharply into some trucks' to reseat a blowing clack, and using the fire irons to ram a bolt into the crown if you drop a plug. It's probably just as well that some things moved on...
     

Share This Page