[steamer_ctn]

A small change has been added to #3374 to allow users to define the amount of SuperElevation applied to curves within a route.

It should be noted that SuperElevation is used by OR in the following three features:
i) Visual depiction of train as it rounds curves, and tilts accordingly.
ii) Calculation of curve forces
iii) Calculation of maximum permissible speed around a curve.

It should be noted that the user defined values will only apply to items ii) and iii) above as item i) uses different algorithms to calculate the amount of superelevation.

To define the amount of superelevation on a curve insert the following statement into the include file for the TRK file. (see the end of this thread for info on the include file).

The statement is as follows:

ORTSTrackSuperElevation ( x1 y1 .................................................. xn yn)

A series of paired values is included in the statement, where the x values represent the curve radius (in metres), and y represents the amount of superelevation on the curve (in metres). As many pairs of values can be entered as desired.

The following statement is an example, and can be loosely interpreted as no superelevation on curves below 50m, 25mm on 300 and 400m curves, 50mm on 500m curves, etc.

ORTSTrackSuperElevation ( 0.0 0.00  50.0  0.0   300.0 0.025   400.0 0.025   500.0 0.050  1000.0 0.075  2000.0 0.100   10000.0 0.100 )

NOTE: If this parameter is not included, then the current default values of superelevation will be used. Thus this is an option and not a requirement.

These tables based upon FRA (Federal Railway Administration) standards give an indication of the amount of superelevation that might be applied to more modern railways. Older and narrow gauge railways may not use the same values.

This article provides an insight into the potential impacts of poor driving or designed track, as well as the physics supporting superelevation.

[James Ross]

steamer_ctn, on 14 December 2015 - 01:45 AM, said:

A series of paired values is included in the statement, where the x values represent the curve radius (in metres), and y represents the amount of superelevation on the curve (in metres). As many pairs of values can be entered as desired.

So since we're specifying the super-elevation as a length here, and ORTSTrackGauge is specified in wagons/locomotives, doesn't that make things a bit weird? We also have the experimental super-elevation gauge option which I'm not sure interacts well.

A slightly related question; if I specify ORTSTrackSuperElevation in a route, but do not turn on the experimental super-elevation option (i.e. leave level set to 0), does the super-elevation in the route still take effect? Which gauges does it use?

[Csantucci]

I think that superelevation used for these calculations and visual superelevation should coincide.
In other words: if the ORTSTrackSuperElevation parameter is not used the visual superelevation is derived from the value inserted in the existing Superelevation level parameter within the experimental options;
if the ORTSTrackSuperElevation parameter is used the visual superelevation is derived from such parameter.

[burgerbern]

I have been trying this out on a couple of routes and i am not sure it is working, if i set the experimental one to 1 i get some movement on curves of a certain lean, if i then turn the experimental up to 10 i am surpriosed that the engine does not tip over as the angle is quite marked, but on 0 in experimental nothing happens, in all cases the ORTSTrackSuperElevation parameter was in place in the openrails folder in the route named as per the routes trk name, the tree dissapearing worked but the superelevation did not seem to override the experimental at any time, the open rails include file for the TRK file is set as follows

include ( ../WP3.trk )

ORTSUserPreferenceForestClearDistance ( 2 )

ORTSTrackSuperElevation ( 0.0 0.00 50.0 0.0 300.0 0.025 400.0 0.025 500.0 0.050 1000.0 0.075 2000.0 0.100 10000.0 0.100 )

in the absence of details of how it should be used i had to experiment, but it seemed to me that the experimental setting has to be greater than 0 for anything to happen but never saw the lean in curves to be what was in the include folder it always seemed to be what the experimental part was set to, i was using X3374

EDIT: after re reading the first post i now see that it did not apply to the visual aspect only to the forces involved, so i have been beating a dead horse trying to see a change in the visual.

i was at first excited as it seemed a good idea in my mind to be able like the tree clearance to set up supelevation visually for different routes rather than having to switch it on and of for each one manually, which is why i tried it but now i see it does not include the visuals i will pass on testing as i cannot define any results i get.

[steamer_ctn]

James Ross, on 14 December 2015 - 04:30 AM, said:

So since we're specifying the super-elevation as a length here, and ORTSTrackGauge is specified in wagons/locomotives, doesn't that make things a bit weird?

The track gauge is still better off in the wagon, as a route may support rolling stock with different track gauges.

James Ross, on 14 December 2015 - 04:30 AM, said:

A slightly related question; if I specify ORTSTrackSuperElevation in a route, but do not turn on the experimental super-elevation option (i.e. leave level set to 0), does the super-elevation in the route still take effect? Which gauges does it use?

The superelevation for the visual item i), and the curves forces and speed (items ii) and iii) ) have always been independent, so setting the level to 0 stops the visual, but not the other two. The two tick box options in the Simulation TAB ("Curve dependent resistance" and "Curve dependent speed limit") turn off the superelevation associated with items ii) and iii).

The change in #3374 does not change any of the base functionality in any of the superelevation features, but merely allows the user to override the default superelevation values for items ii) and iii).

Csantucci, on 14 December 2015 - 10:03 AM, said:

I think that superelevation used for these calculations and visual superelevation should coincide.

I agree that it would be good to align them.

I have tried to contact the original developer of the visual superelevation to seek some input. I have also had a quick look at the code for it, and I am still trying to work out how to change if without "breaking" it.

It appears that the method of applying the superelevation values is different betyween the features. The visual method appears to adjust the value of superelevation to allow for a constant route speed, which is probably more applicable for more modern mainline routes. On older and secondary routes track design often allowed for curves to have different speed restrictions.

[Genma Saotome]

Q: How can I get the mathematical effect of SE w/o also turning on any feature that tilts the train? I run late steam era routes (max 65mph) and all I want is enough SE to avoid problems on tighter curves when running at 25-65mph speeds.

[steamer_ctn]

Genma Saotome, on 14 December 2015 - 01:28 PM, said:

Q: How can I get the mathematical effect of SE w/o also turning on any feature that tilts the train?

I am assuming that you do not wish to have the visual effect, and only have the curve resistance and speed limit working.

If this is the case, do the following:
i) Turn the visual superelevation off on the Experimental option by setting the level to 0.
ii) To have the curve resistance and speed limit working ensure that the two tick box options in the Simulation TAB, "Curve dependent resistance" and "Curve dependent speed limit" are ticked.

Genma Saotome, on 14 December 2015 - 01:28 PM, said:

I run late steam era routes (max 65mph) and all I want is enough SE to avoid problems on tighter curves when running at 25-65mph speeds.

If the standard default values of superelevation already in OR are not considered appropriate for the route that is being used, then the following approach could be used to override them with "more relevant" values:

i) Identify the relevant speed limits for the various radius curves on the desired route - for example, the Australian Victorian Railways used the speed limits shown in the table on this web page. This information is often in working timetables, etc.
ii) Use these tables as an approximate guide to determine the superelevation required to support the curve speed limit desired. The amount of unbalanced superelevation will need to be selected and entered into the relevant wagon and loco stock. Based upon the curve radius, unbalanced superelevation (cant deficiency), and and the desired maximum speed, the amount of superelevation can be calculated for various curve radii.
iii) Use the parameter described in the first post to enter the relevant values into OR.

[Genma Saotome]

Thanks Peter, I've give that a try.

[James Ross]

Csantucci, on 14 December 2015 - 10:03 AM, said:

I think that superelevation used for these calculations and visual superelevation should coincide.
In other words: if the ORTSTrackSuperElevation parameter is not used the visual superelevation is derived from the value inserted in the existing Superelevation level parameter within the experimental options;
if the ORTSTrackSuperElevation parameter is used the visual superelevation is derived from such parameter.

Just an FYI: I'm working on this at the moment. There's quite a bit of interconnected code involved in the visual super-elevation, cab vibration and some bits of the simulated curve speed stuff, but I'm slowly getting it in to a (hopefully) better state.

[Aldarion]

When will it be allow to enter a 1668mm gauge in the experimental feature?