Line Gradients

[LucaZone]

Hi,

 

What form to Japanese lines represent ruling gradients?

 

In the UK we have say "200" representing 1:200 or 1 unit vertically for 200 units horizontally. In the US they have %. Across Europe they use PerMil.

 

On Japanese grade profiles I see values like 10.0, 15.0, 20.0 etc

 

Cheers

[bronzeonion]

I think it is in percentage similar to the US

[angusmclean]

Hi,

 

What form to Japanese lines represent ruling gradients?

 

In the UK we have say "200" representing 1:200 or 1 unit vertically for 200 units horizontally. In the US they have %. Across Europe they use PerMil.

 

On Japanese grade profiles I see values like 10.0, 15.0, 20.0 etc

 

Cheers

Japanese gradients are normally permil  eg per thousand, not hundred

 

Angus

[E6系]

Hello Mr LucaZone,

 

Mr Angus is correct.  The measurement is taken as millimeter per meter.  It is with much pleasure that I refer to Ministerial Ordinance No. 110 of December 15, 2006 - Technical Regulatory Standards on Japanese Railways.

 

We must consider Article 18 of the Ministerial Ordinance together with Section III-7 of the Approved Model Specification.  Section III-7 lists approved gradients as fractions of 1000.

 

I cannot believe myself.  I just searched for the Ordinance in Google with English.  There exists an unofficial English version here: http://www.mlit.go.jp/english/2006/h_railway_bureau/Laws_concerning/14.pdf

 

Please refer to page 20 and 21.

 

Also, I find many Railway Bureau documents translated into English here:  http://www.mlit.go.jp/english/2006/h_railway_bureau/Laws_concerning/

 

So sorry to provide much detail.  I hope not overwhelmed.  The original question is of importance.  Critical for the true Japanese rail fan to understand relevant laws and controls affecting the railway, don't you agree?

[miyakoji]

great information and links E6, thanks

[Sacto1985]

Speaking of gradients, what is the steepest operating grade in Japan currently? I think the steepest for JR mainline operations is the "Senohachi" grade between Seno and Hachihonmatsu Stations on the San'yō Main Line.

[miyakoji]

Wikipedia says the Sanyo Line's steepest grade is 22.6 permil. The Iida Line has a 40 permil grade, which I think is the steepest grade amongst the JRs. Not sure about private railways and subways.

[Ronny]

In Italy and almost in continental Europe line gradients are represented in mm/m, it must be a standard rule from UIC Union internationale des chemins de fer

[bikkuri bahn]

I think the steepest grade on an adhesion railway is the Hakone Tozan, with a max 80 permils.  Other notable grades are the Nankai Kouya Line and Kobe Dentetsu Ao Line, with 50 permil sections. The Fujikyu has 40 permil grades.  The steepest heavy mainline railway line in Japan is the Kintetsu Nara Line between Hyotanyama and Ishikiri, with a section maxing out at 35.7 permils. I recommend a visit to this stretch of track, besides the steepness and sloping station platforms (33 permils at one, I think), you get a nice view of the Osaka skyline on a clear day.

[E6系]

great information and links E6, thanks

 

Most welcome Mr Miyakoji.