Gradient in scheme plans

[il0054]

Hi all,

Is anyone able to explain the gradient system and symbols in documents such as signalling scheme plans? I've attached an example. What are the different ways these can be expressed as a number or percentage?

Thanks!

 

[The Planner]

The slope tells you which way the fall or gain is. 1 in 3698 is pretty much flat!

 

[zwk500]

Hi all,

Is anyone able to explain the gradient system and symbols in documents such as signalling scheme plans? I've attached an example. What are the different ways these can be expressed as a number or percentage?

Thanks!

gradients are expressed in terms of 1 in X on Scheme plans, so for 1m rise or fall, you'd travel 871m for the left-hand gradient and 3698m for the right-hand.

 

[edwin_m]

British railway gradients are traditionally shown as "1 in" so going left to right, this would be a transition from 1 in 871 downwards (1 metre down for every 871 metres travelled) to 1 in 3698 downwards (1m down for every 3698m travelled).

Gradients are probably more commonly expressed as percentages, for which divide 100 by the figure shown, or per mille, for which divide 1000 by the figure shown.

 

[30907]

I presume the bottom figure is the location: 342m from milepost 5 3/4 (!)

BTW: UK Road signs were also expressed as 1 in x until well after the introduction of the standardised "European" pictograms. Promille is a long-standing European rail convention.

 

[il0054]

British railway gradients are traditionally shown as "1 in" so going left to right, this would be a transition from 1 in 871 downwards (1 metre down for every 871 metres travelled) to 1 in 3698 downwards (1m down for every 3698m travelled).

Gradients are probably more commonly expressed as percentages, for which divide 100 by the figure shown, or per mille, for which divide 1000 by the figure shown.

Thanks for the replies. Do you mean multiply by 100 and 1000? For example... if we want to convert to a percentage we say (1/3698)*100 = 0.027% gradient
or (1/3698)*1000 = 0.270 per mille?

 

[zwk500]

Thanks for the replies. Do you mean multiply by 100 and 1000? For example... if we want to convert to a percentage we say (1/3698)*100 = 0.027% gradient
or (1/3698)*1000 = 0.270 per mille?

Either method will work: (1/3698)*1000 or 1000/3698 comes to the same thing. Substitute 100 for 1000 if using percent not permille.

Railway is typically permille because steep gradients are rare, so the finer scale makes it easier to see smaller variations.