There Are 4 Rails on Railway Bridges, But Why?

Ғылым және технология

Hello railway people, welcome to my new educational video about railways. Today, I will explain why we have 4 rails on bridges, but some other places as well.
This was something that bothered me few years back as well, especially as I was very interested in track design. Reason behind having 4 rails on bridges is very logical, to prevent train flipping over the bridge if derailment happens.
Note that not all bridges have them, depending on country, bridge position and similar. However, as a track designer I would always suggest to have them, as they can be efficient in reducing infrastructure damage or higher fatalities.
Let me know what you think about this in comment below. I would appreciate if you like, share or subscribe to my channel. This helps other people find out some interesting facts about railways too.
Railway Track Design Course: www.railgenics.com/rail-track...
My website: www.railgenics.com/
Music by bensound.com

Пікірлер: 25

  • @rogerfroud300
    @rogerfroud300Ай бұрын

    You could also argue that the additional rails stabilise the position of the sleepers, giving additional strength to the track and helping to reduce the chances of buckling and movement.

  • @josephma9332
    @josephma933227 күн бұрын

    Guard rails are provided on bridges and other vulnerable locations to prevent derailed vehicles from hitting nearby structures and falling off. Also they give stability to the track over the girders. Check rails are provided on sharp curves along with the inner running rail to prevent derailment. Also they are provided in level crossings for flangeway clearance. On certain bridges on sharp curves both guard and check rails are used.

  • @erniemathews5085
    @erniemathews5085 Жыл бұрын

    I always wondered. Thanks.

  • @kqschwarz
    @kqschwarz3 күн бұрын

    Short and sweet, I love it.

  • @stroberi1238
    @stroberi1238 Жыл бұрын

    Are there any recorded cases where guardrails actually helped?

  • @thenetheriteminecart384

    @thenetheriteminecart384

    Ай бұрын

    They are called check rails, not guard rails, just to clarify things a little bit, and they are usually on bridges, tunnels and tight curves to keep a derailed train moving in the same direction instead of diverting off of a bridge or into a tunnel wall. Here is a short video that gives an explanation of why more than 2 rails: kzread.info6kduAGfbx7U it tells you about duel gauge (usually 4 rails or gornplet track which is 4 rail duel gauge and about check rails which also are on points)

  • @ThePaulv12

    @ThePaulv12

    Ай бұрын

    @@thenetheriteminecart384 It's called gantlet or gauntlet track not gornplet track. It can and is called guard rail.

  • @thenetheriteminecart384

    @thenetheriteminecart384

    Ай бұрын

    @@ThePaulv12 Here in Australia, the UK and in many other European countries we call it check rails, and sorry for the typo but it is pronounced as gornplet track, although Australia is more in Asia but is its own continent if that makes any sense but Australia speaks kinda British but some things are American styled, it's a hybrid of the UK and America.

  • @bellowphone

    @bellowphone

    27 күн бұрын

    @@ThePaulv12 I looked at that and I was going "gornplet??" Too bad it's not a real word, it's mighty funny.

  • @McRocket
    @McRocket27 күн бұрын

    I didn't know this. Thank you. ☮

  • @goziegoziego232
    @goziegoziego2323 ай бұрын

    Thanks❤

  • @LearnwithJanice
    @LearnwithJanice26 күн бұрын

    Hello from Kansas 🇺🇲

  • @davidchapman1519
    @davidchapman1519 Жыл бұрын

    Thought this was common knowledge

  • @bellowphone

    @bellowphone

    27 күн бұрын

    Not for me; I've always looked at those extra rails, and wondered.

  • @neumoi3324
    @neumoi332427 күн бұрын

    When you look at the pictures of train derailments and accidents it is indeed doubtful if these check rails / guard rails (by whatever name you call them) serve the purpose they are there for (to prevent wheels from slipping laterally). In many an accident the bogies / trucks have entirely flown off the rail. The wheels are lying several meters away from the rail. I think the check rails only help to keep the sleepers firmly below the rails (or conversely the rails on the sleepers) at the turnings and on bridges so that the sleepers and rails do not move laterally due to the centripetal force generated by the trains at the curves. I find it hard to imagine that they are there for the same function at road level crossings also. Now carefully look at the stretch of rail in a bridge (@2:21 where a lineman is inspecting the rails) in addition to the check rails there are other serrated structures running on both sides of the rails. The rails are so heavily secured that the purpose of the check rails clearly seems to be to provide additional lateral stability to the rails in the bridges.

  • @graemehamilton-gs7wp
    @graemehamilton-gs7wp Жыл бұрын

    Koo chears

  • @hentichan
    @hentichan2 жыл бұрын

    just one hint, if you talk about something, explain ALSO how it works, not only why its there Edit: please look at " ccrx 6700 That's Railroadin! ", he does a better explanation, where he also explain, how it should work to prevent cars from falling down. if you do this on your Vids, than they will be a lot better

  • @railgenics

    @railgenics

    Жыл бұрын

    Thanks for hint, I will make it better next time :)

  • @Inkling777

    @Inkling777

    Жыл бұрын

    I agree. I wanted to know how these guard rails work. What do they do to make a derailment less likely?

  • @railgenics

    @railgenics

    Жыл бұрын

    ​@@Inkling777 They do nothing to make derailment less likely. That's not why they are placed on the track. They are there in case a derailment happens. Their function is to serve as another rail which will be hit by a train wheel when it derails. The idea is that the train wheel bounces off this rail and stays in between track rail and guard rail. That will prevent the train bouncing off the track during derailment, but also protect it against flipping over. Of course, this is not guarantee that it won't happen, as it depends on many factors such as speed, train type, track geometry etc. Main reason why they are placed on bridges and stations is that those are critical places in terms of infrastructure, interaction with other modes, number of people interacting at stations for example, etc. Hopefully this explains a bit more.

  • @tetedepoulet8651

    @tetedepoulet8651

    7 ай бұрын

    Yes, the WHY would be nice

  • @bellowphone

    @bellowphone

    27 күн бұрын

    @@tetedepoulet8651 I understood the why, from his explanation.

  • @wade3217
    @wade32179 ай бұрын

    Now I know

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