Superelevation

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In the left column, seize the '''minimum radius of curvature''' that can know your network, a maxi speed and choose the gauge (standard or metric).
 
In the left column, seize the '''minimum radius of curvature''' that can know your network, a maxi speed and choose the gauge (standard or metric).
  
Observe the parameter Superelevation (SE) calculated. If it exceeds 6.3 inch in standard gauge or 3.94 in metrics, it is necessary to decrease the maxi speed (according to French standards).
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Observe the calculated parameter of Superelevation (SE). If it exceeds 6.3 inch in standard gauge or 3.94 in metrics, it is necessary to decrease the maxi speed (according to French standards).
  
 
The parameters p1 and p2 then obtained can apply to all the curves of your network, whathever is their radius of curvature, since the maxi speed will not exceed the one that you seized in the spreadsheet.
 
The parameters p1 and p2 then obtained can apply to all the curves of your network, whathever is their radius of curvature, since the maxi speed will not exceed the one that you seized in the spreadsheet.
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[[File:12.jpg]]
 
[[File:12.jpg]]
  
An example:
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'''An example:'''
  
 
In the spreadsheet, you seize the values beam = 150 ft, speed = 55 mph  and standard gauge. And you obtain a superelevation = 5 in, p1 = 43.73 and p2 = 0.089 radians.
 
In the spreadsheet, you seize the values beam = 150 ft, speed = 55 mph  and standard gauge. And you obtain a superelevation = 5 in, p1 = 43.73 and p2 = 0.089 radians.
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You put a track with these parameters and you make vary the beam of the curve:
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- If the beam is 150 ft, the superelevation will be 5 inches and the angle of inclination of the way of 0.089 radians
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- If the beam is 300 ft, the superelevation will be 2.5 inches and the angle of inclination of the way of 0.044 radians
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- If the beam is 75 ft, the superelevation will be 10 inches and the angle of inclination of the way of 0.178 radians.
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If the speed of your trains does not exceed 55 mph, the installation is correct. Except that in this example and for a 75 ft beam, the superelevation exceeds the authorized 6.3 inches. By means of the spreadsheet, look for the maxi speed which, for a 75 ft beam, allows to respect a maxi superelevation of 6.3 inches. Apply the new parameters p1 and p2 to your curve.
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'''Other points to be respected:'''
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- There is no superelevation for speeds lower than 15.5 mph in standard gauge and 18.5 mph in metrics (French standards, 25 kmph and 30 kmph)
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- On networks with gauge of 2 ft or less, the speed is limited to 15.5 mph (25 kph) : there is thus no superelevation either.
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On the spreadsheet, the right column allows you to calculate p1 and p2 from the values of chord and arrow of a curve.

Revision as of 02:14, 8 November 2015

The "superelevation" or the slope of rails in curves is proposed from now on in T:ANE.

Here is the example of a machine launched to 80 kph in a curve of 500 meters of beam. Its slope has to be 4 ° to resist the centrifugal force and not not wear out prematurely the outer rails.

5.jpg


However, the implementation of the superelevation in T:ANE is little transparent for the moment. Here is thus a small guide who will supply you all the necessary elements.


In T:ANE, the superelevation is adjusted by means of two parameters. We reach it by the panel "rail", and " advanced mode " 10.jpg


11.jpg By clicking a summit of spline of track, we reveal both parameters to be served:


Superelevation : short definition

The Superelevation is the height which takes the outside rail compared with the internal rail in a curve.

It is calculated as the plan below shows it:

3bis.jpg


If, to calculate the superelevation, the beam of the curve is unknown, it can be calculated by measuring the arrow and the chord of the curve:

1.jpg

Every country has its own standards of superelevation. We find them rather easily on the internet.

In France, the superelevation does not have to exceed 16 cms in standard gauge way and 10 cms in metrics.


Mode of calculation in T:ANE

To proceed to the calculations, download the spreadsheet here.

In the left column, seize the minimum radius of curvature that can know your network, a maxi speed and choose the gauge (standard or metric).

Observe the calculated parameter of Superelevation (SE). If it exceeds 6.3 inch in standard gauge or 3.94 in metrics, it is necessary to decrease the maxi speed (according to French standards).

The parameters p1 and p2 then obtained can apply to all the curves of your network, whathever is their radius of curvature, since the maxi speed will not exceed the one that you seized in the spreadsheet.

12.jpg


An example:

In the spreadsheet, you seize the values beam = 150 ft, speed = 55 mph and standard gauge. And you obtain a superelevation = 5 in, p1 = 43.73 and p2 = 0.089 radians.

You put a track with these parameters and you make vary the beam of the curve:

- If the beam is 150 ft, the superelevation will be 5 inches and the angle of inclination of the way of 0.089 radians

- If the beam is 300 ft, the superelevation will be 2.5 inches and the angle of inclination of the way of 0.044 radians

- If the beam is 75 ft, the superelevation will be 10 inches and the angle of inclination of the way of 0.178 radians.

If the speed of your trains does not exceed 55 mph, the installation is correct. Except that in this example and for a 75 ft beam, the superelevation exceeds the authorized 6.3 inches. By means of the spreadsheet, look for the maxi speed which, for a 75 ft beam, allows to respect a maxi superelevation of 6.3 inches. Apply the new parameters p1 and p2 to your curve.


Other points to be respected:

- There is no superelevation for speeds lower than 15.5 mph in standard gauge and 18.5 mph in metrics (French standards, 25 kmph and 30 kmph)

- On networks with gauge of 2 ft or less, the speed is limited to 15.5 mph (25 kph) : there is thus no superelevation either.


On the spreadsheet, the right column allows you to calculate p1 and p2 from the values of chord and arrow of a curve.

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