restraining rails in japan

[cteno4]

So i have gotten curious about restraining rail use in japan. I notice it on a lot of urban track in youtube on curves. i would guess as Japanese trains tend to run at higher speeds on tighter radiuses in urban commuter rain in japan, but also see them out in the country on videos that seem pretty slow speed. also seen them on a lot of straight trestle sections on both rails, im assuming as a safety to derailment.

 

anyone know what the general rules of thumb are? also any classic cross sections of guard/restraining rails in japan. it doesnt look any higher than the regular rail and looks like pretty similar rail but you never see it close enough in detail.

 

dont see many folks including it in their models either. thinking it might be a fun detail to play with.

 

cheers

 

jeff

[bill937ca]

You mean guard rail?   There are photos in Japanese Wikipedia.

 

http://ja.wikipedia.org/wiki/脱線防止ガード

 

For the prototype Ministry of Land, Infrastructure Transport and Tourism technical regulations require guard rails on curves (as determined by a formula), on ballast-less bridges and at level crossings.

 

For model trains this more of a fine scale thing. Tolerances will be very tight.  You would need clearance so the wheels don't hit the guard rail and pop up off the rail.

Edited June 6, 2013 by bill937ca

[cteno4]

thanks bill. better closeups there as well. should be easy to do in n scale as an addon, tolerance is not that close.

 

seen them called both guard and restraining rails, restraining rail sound more British!

 

jeff

[marknewton]

I dunno about that Jeff, in the UK and Australia they're called guard rails, at least by traincrew. The perway blokes sometimes calll them check rails.

 

Cheers,

 

Mark.

[cteno4]

Ha just sounded more British. The one tech pub I saw called them both terms.

 

Jeff

[E6系]

Hello Mr Jeff,

 

It is my pleasure to answer this question.

 

Firstly, the term "guard rail" is appropriate translation and is generally used in English documents on the subject of railway.

 

Secondly, the matter of when the guard rail is to be used is specified in the Ministerial Ordinance to which I referred recently here: http://www.jnsforum.com/community/topic/7332-line-gradients/?do=findComment&comment=81597.  Please refer to the following sections:

 

- Section 2, Article 13 Guide Way Alignment on p13

- III-2 Related to Article 13 - Guide Way Alignment on p13

- Section 5, Article 23(2) Protective Devices on p28

- III-12 Related to Article 23 - Track - 4.1 on p30

 

These sections set down the criteria and also the calculation to use in order to determine the requirement of guide rail or not.

 

More information I cannot provide.

[cteno4]

Thanks E6,

 

also on steep embankments as well.

 

im now interested in what the cross section is like for the standard japanese guard rail is. im thinking a second piece of code 80 rail right up against the spikes might work. or just rectangular plastic stock. im guessing the guard rail must be a tad higher than the rail head. hard to see from most shots.

 

jeff

[bill937ca]

If its higher than the rail its called high guard rail.  Usually only seen on sharp streetcar / tram curves.  There's high guard rail outside my hotel in LIsbon. I know I have to carry my luggage across it!

 

An example:

 

Edited June 8, 2013 by bill937ca

[E6系]

Hello Mr Jeff,

 

It is my pleasure to provide this further assistance.

 

I have searched for guard rail profile and found one patented to JR Central.  I entered the patent number and found this link in English: http://www.google.com/patents/EP2216440A1?cl=en

 

Please click on the images to see the profile in detail.

 

As to how to model it, I would suggest a very small Z profile but even I would be interested to see what you can find.

[cteno4]

E6

 

Thank you very much! pretty much the cross section i saw in the one rr tech journal i had seen a while back. im thinking a piece of code 80 n scale rail upside down. it wont be off center, but the rail base seems about the width of the guard rail head. elevating it could be small bits of styrene L stock that would pop it up just a tad and also move it the desired distance from the spikes to make the proper flangeway. 

 

ok time to dig out the box of old rail bits and the styrene stock tubes and fiddle!

 

It was interesting to see the detail of the idea of having a ring there in the center of the axle that would catch the guard rail to keep a derailment from completely leaving the tracks!

 

Thanks again for the great info!

 

jeff

[KenS]

The patent is an interesting approach to guard rails, but I expect many of them are merely conventional rail attached inside the running rails.  I've certainly seen some of those in photos from Japan.

 

In U.S. practice, guard rail is often older rail that's too worn for mainline use, and thus often of a lower profile than the rail it protects.  On tight-curve subway track I think it's more commonly the same height, but I've never had an opportunity to examine that closely.

 

The comment in the patent about placing it outside the running rail in falling rock or snow areas makes sense, although I'd never run across anyone doing that before.  Street-crossing guard rail gaps often fill with packed snow and freeze in the winter.  I've heard of push-pull commuter trains derailing due to that, as the cab car isn't heavy enough to crush the ice out of its way.

[Ochanomizu]

Hello Mr cteno4,

 

I remember on G-Gauge World (it is Japanese website for the G gauge modelling fan) the information about various railway accessories including guard rails.  You can find it here: http://g-gauge.world.coocan.jp/turnout/other.html

 

Edit:

 

The third picture match the drawing provided by E6系.

Edited June 11, 2013 by Ochanomizu

[cteno4]

Ochamomizu,

 

Thank you very much, great detail shots there. lots of old rail there used in interesting ways for guard rails. 

 

jeff