There Are 4 Rails on Railway Bridges, But Why?

[@josephma9332]

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.

[@rogerfroud300]

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.

[@jain-wt2ou]

And loco pilots will be aware that you they are about to cross a bridge by seeing the gaurd rails.

[@erniemathews5085]

I always wondered. Thanks.

[@kqschwarz]

Short and sweet, I love it.

[@stroberi1238]

Are there any recorded cases where guardrails actually helped?

[@thenetheriteminecartzactnm]

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: kzbin.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]

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

[@thenetheriteminecartzactnm]

@@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]

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

[@McRocket]

I didn't know this. Thank you. ☮

[@mr.russerzplace...1448]

I'd say it's for more stability and integrity of bridge support itself . I've heard it prevents derailment. Its possible that check rails might help prevent the train from goin right over the edge but let me remind you that these trains are extremely heavy and powerful plus they are built solid virtually indestructible. Even when the derailment or wreck is catostrofic and it looks like the end of the line for the locomotives -most of the time it's not . They take the worst looking wrecked locomotives and rebuild restore them and off they go back in service . And when that's not the case usually the parts are used in other broken or wrecked units . To say the check rails will take on a mile of rolling steal out of control and guide it to not go right over the side is saying a lot Don't you think ?

[@mr.russerzplace...1448]

Almost anything you could use to challenge a freight train is the same as choosing different kinds of objects to throw at an exposed lawn mower blade spinning at 4000 rpms claiming your goin to shut it down . Maybe an anvil or car tire ect. That's the same as using kamatsu cat used for mining or the platform that moves the space shuttle at nasa to stop a freight train going 60mph ..sure yes but that's insane .

[@LearnwithJanice]

Hello from Kansas 🇺🇲

[@davidchapman1519]

Thought this was common knowledge

[@bellowphone]

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

[@goziegoziego232]

Thanks❤

[@neumoi3324]

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]

Koo chears

[@hentichan]

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]

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

[@Inkling777]

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

[@railgenics]

​@@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]

Yes, the WHY would be nice

[@bellowphone]

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

[@wade3217]

Now I know