chains on trucks?

Discussion in 'FAQs' started by nachoman, May 19, 2008.

  1. nachoman

    nachoman Guest

    I have noticed that many steam engine tenders and passenger cars have short lengths of chain joining the truck sideframes to the car body. I guess I have always noticed them, but today I got to thinking why they are there. Does anyone know why? And why not on standard freight cars? Obviously, they limit the swing of the truck, but in what circumstances would the truck swing too far?

  2. UP SD40-2

    UP SD40-2 Senior Member

    Kevin:wav: , as i understood it, the chains are there for two reasons, to keep the trucks with the car in the event of an accident, so the trucks don't roll away, or go flying off doing damage to anything nearby:winki: .

    for some odd reason if the car ran aground, etc., to keep it up in a "jackknife" situation.

    EDIT: you have a good question:thumb: , DON'T take my answer to the bank though, the info i gave you was passed on to me, i could have been misinformed:eeki: , lets see what other folks say, i am curious.

    :deano: -Deano
  3. nachoman

    nachoman Guest

    this is kinda what I was thinking, but why only on tenders and passenger cars? Human safety for some reason?

  4. logicman

    logicman Greybeard

    Hi, all.

    In the UK, these safety chains were fitted up to about 1920s on tenders, passenger stock and luggage vans. They were 'breakaway' chains - a fail-safe device - as used on the highways, on trailers.

    Our screw and chain type couplings reduced discomfort by keeping stock close-coupled, but apparently, early examples were prone to fail. It's linked to the reasons behind the red light on the rear of the train - if you're a signalman, and you see a loco and 20 wagons roll by with no rear red light -

    you can reliably expect another 20 wagons to roll by shortly!

    Safety chains keep signalmen's heart rates within the specified safety levels.

  5. doctorwayne

    doctorwayne Active Member

    As Deano said, it's to keep the trucks with the car in the event of a derailment. Rail cars simply sit on their trucks (there's no giant screw holding the truck in place) ;): the chains prevent the trucks from separating from one car and ending up hitting another, causing even more damage and injuries

  6. nachoman

    nachoman Guest

    So, in the event of a derailment on passenger trains and tenders, the chains keep the truck from flying off and smashing into another car or the loco cab, thus reducing injuries. I guess that makes sense.

  7. logicman

    logicman Greybeard

    Ah! I'm sure you can hear the sound of the penny dropping, all the way across the pond!

    So, ingrish 101: 'truck' = 'the bit with wheels on', not 'the whole darn wagon'?


    (Need more coffee.)
  8. doctorwayne

    doctorwayne Active Member

    Sorry about that: wagons/cars, trucks/bogies - it's still English, but not quite English. ;):p:-D:-D

  9. Jim Krause

    Jim Krause Active Member

    As a friend of mine in London once commented, "Two (or three) countries separated by a common language"
  10. logicman

    logicman Greybeard

    Oi! Don't go calling my mother tongue common.

    Oooops! There goes another misunderstanding. wall1
  11. steamhead

    steamhead Active Member

    So what is the "king pin"...I've always thought that was the "screw" in real-life cars/trucks....
  12. bigsteel

    bigsteel Call me Mr.Tinkertrain

    so,if a pin is the only thing holding a truck on how do regular freight car trucks keep from flying off in a collision without the chains?--josh
  13. doctorwayne

    doctorwayne Active Member

    They don't - in a wreck, they're all over the landscape. :eek:;):-D

  14. Russ Bellinis

    Russ Bellinis Active Member

    Josh, I think the issue is safety for people rather than a concern that the trucks are somehow tied to the car. The chains are used on the locomotives and passenger cars because both are occupied by people who could be injured or killed by flying trucks. Nothing keeps the freight car trucks from flying off because there is generally no one around when a freight car derails.
  15. bigsteel

    bigsteel Call me Mr.Tinkertrain

    thanks for the answer,so if a truck falls off and nobody is around to hear it,does it make a sound ? :D --josh
  16. ScratchyAngel

    ScratchyAngel Member

    When I first saw the thread I imagined somebody making traction chains on tires on a Z scale wheel for semis heading through the mountain passes :D
  17. logicman

    logicman Greybeard

    Hey, scratchy,

    if you find "chains on trucks" a bit confusing over there -

    just try being British.wall1wall1wall1

  18. logicman

    logicman Greybeard


    These tornado sound effects brought to you by:
    Chuck-a-Truck Inc.
  19. logicman

    logicman Greybeard

    Thanks, Charlie.

    No, I didn't know that. It makes your merry jest even funnier.:thumb::thumb:

    All I know about tornados is that the RAF used to own a few.

  20. railwaybob

    railwaybob Member

    If you ever see a train derailment on television in North America (can't speak for the rest of the world) you will see wheelsets all over the place. Your first comment will be "where in the world did all of those wheels come from?"

    Next time you see a freight train roll by, take a look at what's holding the axles in place. With the advent of the roller bearing wheelset, it's simply the weight of the car on the side bolsters that keeps the wheelsets in place.

    So, when the car(s) tip over on their sides, the wheelsets come loose and continue rolling down the tracks. The first thing that the rescue gang do is move all of those wheelsets off to the side of the track so that they can move their rescue equipment in.

    In most cases, the old-fashioned railway crane has been replaced by "side-booms" - the kind you see in pipeline construction - and power shovels. The side-booms are used to either put the car back on the tracks or to move it out of the way. The power shovels have a special attachment where the bucket usually is. Flat-bed trucks come in with "snap track" which the power shovels off load and walk down the side of the track with a piece of "snap track" hanging from the end of their boom. The damaged track is simply cut out and moved to the side. Pieces of snap track are used to rebuild the track.

    This opens up the mainline pretty fast and the clean-up crews can do their job at their leisure - provided there are no haz-mat spills.

    Bob M.

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