Converting surveyor gradients to real world gradients?
- Thread starter Davie_UCF
- Start date
cascaderailroad
New member
It's in % which is based on the number 10, 100, 1000 ... etc ...
Metric system is the way to go
Metric system is the way to go
Thanks!
I found this which seems to be useful
http://www.trainman.id.au/grade.htm
Would the grades just be rounded up or down instead of having like 1 in 34 for example?
I found this which seems to be useful
http://www.trainman.id.au/grade.htm
Would the grades just be rounded up or down instead of having like 1 in 34 for example?
Saxham_Market
New member
This example is an original concrete M&GN gradient post (located near Kelling Heath Halt if I remember correctly) on the North Norfolk Railway / Poppy Line. It suggests that the only rounding is to the nearest whole number.
Moving a few miles away, I have one of the Middleton Press books for the East Suffolk Railway that includes a gradient profile from LNER days. Quoted gradients include 1 in 131, 1 in 143, 1 in 74, 1 in 93 and 1 in 94. It even shows a gradient of 1 in 899. Again, it looks as though the gradients are quoted as whole numbers.
I wouldn't worry about rounding in Trainz too much - either way is fine. Just check every so often that you not getting too high out of the ground or too deep, if you have long continuous gradients.
In reality, changes over the years would mean that gradients posts were a guide to the ruling gradient of a section, rather than an absolute measurement of the continuous gradient.
Changes to gradient often come about when track is re-ballasted, and to get round settlement of the track bed, or to maintain clearance on an overline bridge that has settled, to give a few examples.
In reality, changes over the years would mean that gradients posts were a guide to the ruling gradient of a section, rather than an absolute measurement of the continuous gradient.
Changes to gradient often come about when track is re-ballasted, and to get round settlement of the track bed, or to maintain clearance on an overline bridge that has settled, to give a few examples.
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cascaderailroad
New member
IDK about the UK and elsewhere.
In the US most mainlines are 1.25% or less, 2% is getting really steep for modern mainlines. There are exceptions such as Saluda and other really steep grades as high as 4%, but that is really way to steep, except for backwoods geared loco's, heislers and shays
In the US most mainlines are 1.25% or less, 2% is getting really steep for modern mainlines. There are exceptions such as Saluda and other really steep grades as high as 4%, but that is really way to steep, except for backwoods geared loco's, heislers and shays
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On main lines?
Generally something like:
1/100 to 1/200 or less if at all possible
1/75 to 1/100 if necessary for short distances
1/50 to 1/75 if absolutely necessary for short distances.
below 1/50 only in extreme circumstances - Lickey incline and Exeter St Davids to Exeter Central, for example
On secondary lines steeper gradients were encountered more often, as it kept the civil engineering costs down when building the line, at the expense of higher operating costs ever after.
Industrial railways did their own thing, and had some very steep gradients in some places, especially applies to Dock and Colliery railways.
HTH
Generally something like:
1/100 to 1/200 or less if at all possible
1/75 to 1/100 if necessary for short distances
1/50 to 1/75 if absolutely necessary for short distances.
below 1/50 only in extreme circumstances - Lickey incline and Exeter St Davids to Exeter Central, for example
On secondary lines steeper gradients were encountered more often, as it kept the civil engineering costs down when building the line, at the expense of higher operating costs ever after.
Industrial railways did their own thing, and had some very steep gradients in some places, especially applies to Dock and Colliery railways.
HTH
narrowgauge
92 year oldTrainz veteran
Google for it and get a conversion calculator.
Peter
Peter
ray_whiley
Active member
The steepest mainline gradient in the UK - the Lickey incline, south of Birmingham, 1:37 - a heavy banker, 'Big Bertha', was used in steam days to ssist trains up by pushing from the rear.
The steepest on a secondary line was in the Forest of Dean - 1:30.
There were of course steeper inclines elsewhere, eg. on the Cromford and High Peak, but cable haulage was used.
Early railways in the UK used gradients such as 1:2000 because the brakes were so poor.
Somewhere I have seen a reference to the most gentle gradient in the UK which was all but level, but I would have to search through books to find it.
The following may be of interest:
BR Main Line Gradient Profiles [Paperback] (Ian Allan Publishing )
http://www.railsigns.co.uk/sect24page1/sect24page1.html
Ray
For a comprehensive guide on all aspects of UK signalling and signs, see http://www.railsigns.co.uk/home.html
For a technical explanation, http://en.wikipedia.org/wiki/Grade_(slope)
The steepest on a secondary line was in the Forest of Dean - 1:30.
There were of course steeper inclines elsewhere, eg. on the Cromford and High Peak, but cable haulage was used.
Early railways in the UK used gradients such as 1:2000 because the brakes were so poor.
Somewhere I have seen a reference to the most gentle gradient in the UK which was all but level, but I would have to search through books to find it.
The following may be of interest:
BR Main Line Gradient Profiles [Paperback] (Ian Allan Publishing )
http://www.railsigns.co.uk/sect24page1/sect24page1.html
Ray
For a comprehensive guide on all aspects of UK signalling and signs, see http://www.railsigns.co.uk/home.html
For a technical explanation, http://en.wikipedia.org/wiki/Grade_(slope)
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Kennilworth
Active member
Hi
To convert percentages to grade divide 100 by the % figure. e.g. 3% = 100/3 which is the equivalent of 1 in 33.
Regards
Brian
To convert percentages to grade divide 100 by the % figure. e.g. 3% = 100/3 which is the equivalent of 1 in 33.
Regards
Brian
ray_whiley
Active member
I've just discovered that Dainton (UK) was 1:36 - slightly steeper than Lickey.
Ray
Ray
cascaderailroad
New member
I laid track from Altoona to the summit in Tunnelhill and leveled it all out to a 1.25% grade ... it looked great ... but it was all wrong.
Real RR gradients are hundereds if different gradients, all hooked together. One section might be +1.25%, and the next section +0.67%, with the next section being downhill at -0.67% ... much like a rollercoaster
Real RR gradients are hundereds if different gradients, all hooked together. One section might be +1.25%, and the next section +0.67%, with the next section being downhill at -0.67% ... much like a rollercoaster
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So on a branchline or mainline UK route what would you say the steepest gradient in trainz language should be as a guide? somewhere around 3.00?
This is one bit of my route,
Uploaded with ImageShack.us
Is that an extreme gradient?
This is one bit of my route,
Uploaded with ImageShack.us
Is that an extreme gradient?
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ray_whiley
Active member
Model railway/railroad practice aims at a minimum of 1:30, which as I've said earlier is the steepest found in the UK on a protype main line - but this is because of the limited space available.
In Trainz I would suggest aiming at something prototypical. The earlier post by Saxham Market gives some good suggestions.
Ray
Here is a site which gives a good selection of gradients in Scotland - http://www.jhowie.f9.co.uk/gradients.htm
In Trainz I would suggest aiming at something prototypical. The earlier post by Saxham Market gives some good suggestions.
Ray
Here is a site which gives a good selection of gradients in Scotland - http://www.jhowie.f9.co.uk/gradients.htm
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cascaderailroad
New member
3% is a bit steep.
Using math you can add: 1.17 + 1.57 + 1.97 - 2.44 and divide by 4, and come up with an average gradient of 0.57% but then again that is how I screwed up the PRR East Slope prototype gradients.
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ray_whiley
Active member
Here's a gradient to try - 1:5500 (yes, this is a four digit number, not a typo) on the line across the marshes near Breydon Junction between Reedham and Yarmouth Vauxhall. This is a rise of 1 metre in over seven and a half Trainz baseboards.
Ray
Ray
Hi David -
I've been trying to wrap my head around gradients as well, so this thread has been really handy. Using the formula provided by Kennilworth above, the gradients shown in your screenshot translate into the following:
2.44 = 1 foot (or meter) rise in 41 foot (or meter) run [100/2.44 = 40.98]
1.97 = 1 in 51
1.57 = 1 in 64
1.17 = 1 in 85
Based on the numbers provided by stovepipe, most of the grades in your example fall into the extreme to "only if absolutely necessary" range.
Anyway, for my purposes (being in the US), I'll plan to limit myself to numbers less than 1.25 (1 in 80) as cascaderailroad suggests for my mainlines.
Thanks, everyone, for a very informative thread!
Ben