Altitude on Gradient Profiles

[MisterSheeps]

Very few gradient profiles I have seen have altitude information, even of major summits. It seems as if it could be useful information e.g. freezing level. Why omit it?

 

[BluePenguin]

What is this regarding? :-/

 

[MisterSheeps]

What is this regarding? :-/

very apt smilie. Just curious, line is surveyed, surveyor knows altitude, why not put it on the diagram? Icy rails above e.g. 800feet, but gradient profile Y (altitude) is neither calibrated nor to scale.

 

[Gloster]

Train crew, signalmen, PW inspectors, etc. only need to know the gradient: they don’t need to know the altitude. It is never a good idea to clutter up a diagram or similar with unnecessary information.

 

[MisterSheeps]

clutter up a diagram

Makes sense, thank you ... I didn't think of it in that way

 

[Senex]

My copy of the Midland Railway's 1902 printed book of gradient profiles shews heights of summits and of lowest points, also of some other significant places along the lines. So at least one company a century ago thought it was worth including some of this information.

 

[Magdalia]

Very few gradient profiles I have seen have altitude information, even of major summits. It seems as if it could be useful information e.g. freezing level. Why omit it?

For most of the UK railway system altitude is not high enough to be significant.

Some major summits have/had summit boards giving the altitude, but I suspect there were there for passengers looking out of the window not for operational reasons. Some of the most important are now in the custody of the National Railway Museum, with replicas on site.

Here are some examples:

Monument.

Replica summit board, 23 August 2021. The original is in the care of the National Railway Museum. The replica was erected by members the Stainmore Railway Company and like the original, the letters were cut out of massive sheets of steel at the Hydram Factory, Ferryhill. However, unlike the...

www.flickr.com

Original Shap Summit board:NRM York. 04/06/12

placed by British Railways (London Midland Region) at Shap railway summit in the 1950's in what was then Westmorland, it was claimed by the National Railway Museum as an item of historic interest and removed in the first decade of the 21st century to the collection at York. Network rail have...

www.flickr.com

 

[jfowkes]

I'm not sure how freezing level would help - I imagine it moves so much that it would be effectively useless to display it as a fixed point.

Do train crews get specialised weather forecasts, same as aviation crews? Knowing the expected freezing level on a particular day might be more useful.

 

[43066]

Do train crews get specialised weather forecasts, same as aviation crews? Knowing the expected freezing level on a particular day might be more useful.

Definitely not.

Ice building up on trains doesn’t affect train handling and is far less critical than it is on aircraft, where it can interfere with aerodynamics, and has caused many fatal accidents over the years.

 

[greatkingrat]

I'm not sure how freezing level would help - I imagine it moves so much that it would be effectively useless to display it as a fixed point.

Do train crews get specialised weather forecasts, same as aviation crews? Knowing the expected freezing level on a particular day might be more useful.

Only the red/yellow/green warnings about low adhesion. In DC areas, control will issue instructions to turn on the deicer if below freezing temperatures are expected.

 

[MisterSheeps]

I'm not sure how freezing level would help

I was thinking if the Met Office issued a freezing level then the railway could warn drivers about icy conditions on parts of lines above that level, by reading off the Y scale of the gradient diagram ... I don't know if ice is significant in the way leafmould is; the Southerrn used to de ice conductor rails, have not read if that extends to running rails.

== Doublepost prevention - post automatically merged: 17 Jan 2023 ==

Midland Railway's 1902 printed book of gradient profiles

Interesting ... was it for public use? or internal to the company? I get the feeling the public then were more interested in the travel experience ... I was reading a book on the Bala - Blaenau branch which mentioned a GWR book on the scenery and features to be seen from the train.

 

[ComUtoR]

I was thinking if the Met Office issued a freezing level then the railway could warn drivers about icy conditions on parts of lines above that level,

My TOC issues ice mode notices on a regular basis.

 

[MisterSheeps]

My TOC issues ice mode notices

Thank you. What do you do then, drive with a view to greater braking distance in mind?

 

[43066]

I don't know if ice is significant in the way leafmould is;

It isn’t at all significant for braking or train handling. “Ice mode” is for third rail units where some traction types, Electrostars for one, can alter their software settings to protect against electrical surges due to ice on the conductor rail (some sub types can also deploy anti icing gel).

 

[Facing Back]

It isn’t at all significant for braking or train handling. “Ice mode” is for third rail units where some traction types, Electrostars for one, can alter their software settings to protect against electrical surges due to ice on the conductor rail (some sub types can also deploy anti icing gel).

That's interesting. Is there anything similar for overhead lines? I seem to recall issues where build up of ice has damaged them?

 

[43066]

That's interesting. Is there anything similar for overhead lines? I seem to recall issues where build up of ice has damaged them?

Not that I’m aware of, and not on the AC traction I sign.

Ice can cause OHLE issues but generally not to the same extent as with third rail. Presumably because conductor rails, with a much bigger flat surface area, can accumulate larger amounts?

 

[ComUtoR]

Thank you. What do you do then, drive with a view to greater braking distance in mind?

When you see the 'ice mode' notice drop in your inbox you know its gonna be a bit archy and sparky out there. You don't specifically change your driving but you might get a little more defensive if you know that your unit starts slipping about a bit. We also have a seasonal notice case where weather updates get posted and you get the occasional warning when NR issues an Adverse weather warning notice.

We used to get pretty decent weather updates but that seems to have fallen by the wayside.

 

[Skie]

Many of the steepest gradients are underground or in tunnels, so it wouldn't be much help

 

[InkyScrolls]

Ice building up on trains doesn’t affect train handling and is far less critical than it is on aircraft, where it can interfere with aerodynamics, and has caused many fatal accidents over the years.

Though it can lead to trains being cancelled if the demister stops working, as happened to the 0515 Leeds - Carlisle this morning, as soon as it reached the fog and -7°C at Hellifield!