Altitude information

[Andy873]

Thanks as always to everyone who's replied to my other topics.

I have re-worked a gradients profile for my old branch line, however I cannot find information as to the height above sea level for the two junctions that connected it to the East Lancashire line.

Using Internet sites, I can get close to the following:

Great Harwood Junction (Blackburn) approximately 435 feet.
Padiham Junction (Rose Grove / Burnley) approximately 430 feet.

Both junctions were indeed higher up than the line itself, but I was wondering if there is any historical railway information which would give the correct heights?

It's difficult with modern maps as both locations have been built over, and of course the line isn't there anymore.

Thanks,
Andy.

 

[rototunablack5]

According to the 1956 OS map here https://maps.nls.uk/view/189181005 Padiham Junction lies astride the 400’ contour as does Great Harwood Junction: https://maps.nls.uk/view/189180261

Short of getting access to the original line survey or an maybe an old Engineers Line Reference I suspect that is as close as you will get.

 

[Magdalia]

I would also like a good source of heights above sea level for railway locations.

When looking at contours on maps, bear in mind that the railway is usually not on the same level as the surrounding land: it will be higher when on an embankment or viaduct, lower when in a cutting or tunnel.

Various summits have location boards with heights above sea level. But that probably doesn't help here!

 

[Ken H]

I would also like a good source of heights above sea level for railway locations.

When looking at contours on maps, bear in mind that the railway is usually not on the same level as the surrounding land: it will be higher when on an embankment or viaduct, lower when in a cutting or tunnel.

Various summits have location boards with heights above sea level. But that probably doesn't help here!

Try https://maps.nls.uk/. Lots of old OS maps there. You may find one thats before the area was built up and when the railway was extant.
(Link takes you to a site to search and view historic map images.)

 

[pdeaves]

If you have a gradient plan (effectively length and angle) you can calculate from a known point. Of course, you need the known point to start with!

 

[Andy873]

I would also like a good source of heights above sea level for railway locations.

When looking at contours on maps, bear in mind that the railway is usually not on the same level as the surrounding land: it will be higher when on an embankment or viaduct, lower when in a cutting or tunnel.

Glad someone else feels the same way as I do.

If you have a gradient plan (effectively length and angle) you can calculate from a known point. Of course, you need the known point to start with!

I did wonder about that, I have the precise distances along the line, it would depend on how accurately the original was drawn. If it is accurate, then we need a little maths here I think.

Thanks,
Andy.

 

[Ken H]

Glad someone else feels the same way as I do.


I did wonder about that, I have the precise distances along the line, it would depend on how accurately the original was drawn. If it is accurate, then we need a little maths here I think.

Thanks,
Andy.

That will be interesting. Railways have complex curves. Translating a straight line on the gradient diagram to the curve on a map will be fun. Especially if they are different scales.
I would use an image manipulator (MS Paint will do it) to make the map and the gradient diagram the same scale on paper.
Put pins in the map at regular intervals along the rail route. Get some cotton or string. Lay it along the bottom of the gradient diagram and mark off points of interest (say changes in gradient). Then wrap the cotton/string along the pins, and you can then mark the points of interest on the map. You could do the same in reverse, to mark points of interest on the map on your diagram, say a contour crossing the railway route.

(Remembering Technical Drawing and Geography at school over 46 yrs ago!)

 

[Magdalia]

If you have a gradient plan (effectively length and angle) you can calculate from a known point. Of course, you need the known point to start with!

Yes. But errors in extrapolating from a fixed point could be cumulative. It would be good to have frequent known points for cross checking.

 

[etr221]

I do wonder whether - and to what extent - the railway (i.e. Network Rail) actually knows itself. TfL have made available a spreadsheet of station depths (I think via FoI), giving track levels at platforms.

But I am unaware of Network Rail having done the same - to any standard (as to what is covered, or not). While I'm sure some altitudes are known - as they are advertised for some summits, it would be interesting to have a comprehensive set of altitudes.