[Weter]

Hello.
Discussing different standards of contact wire height inside the same routes and rolling stock pantograph's accommodation problem, we have touched this kind of problem.
Here I would describe real-world facts and thoughts about their (possible/perspective) implementation in ORTS.

First: there are many standards of electrification, that route builders modeled in their projects for us.
Furthermore, significant part of modeled routes are combination of electrified and not electrified parts, or combining different electrification systems, or include tram/metro/streetcar/narrow gauge pieces as well.
Second: we have different rolling stock models. Sometimes we would like to ride over any route with our favorite locomotive.

[Lamplighter]

That implementation in OR already exists. The OpenRails CZ / SK 1.5 fork, which has already been mentioned several times, can do it. The Czech programmers of this fork have succeeded and can use traction system switching while driving.

from manual:
Overcurrent, undervoltage and anti-slip protection
For the needs of the division of single-system and multi-system locomotives, new functions were created, defined by new ones
entries in the Engine () section. This division defines the behavior of the locomotive during resuscitation, breakdowns and recurrence
commissioning.

New features in the Engine section:
MultiSystemEngine (0) - value 1 indicates a multi-system locomotive *)
MaxCurrentPower (1250A) - maximum indicated current at which the overcurrent protection responds **)
MaxCurrentBrake (650A) - the maximum indicated EDB current at which the overcurrent protection responds
SlipSpeedCritical (40km / h) - the maximum difference between the forward speed and the "speed" of the axles at which it reacts
anti-slip protection ***)
EDBIndependent (1) - the value "1" will enable the EDB function even in a voltage-free state, but only for a limited time.
Suitable, for example, for locomotives lines 350 and 131. The value "0" is suitable, for example, for series 150, 151, 162, 163, 362 and 363,
which need voltage on the filter to excite the EDB and the filter can only be charged with voltage from the contact wire.

* Single-system locomotive: It is necessary to turn on the main switch first, then it is possible to lift the pantographs.
Switching off HV (manually or by means of protections) also drops the collectors.
Multi-system locomotive: It is necessary to lift the pantograph first, after voltage detection it is possible to switch on HV.
In the power-free state, the pantograph can be lowered and lifted without opening the HV, but after opening the HV with the
the collectors can no longer be switched on in the de-energized state HV. HV shutdown (either manually or by intervention) does not match
collectors.

** This is not the real current of the traction motors, but the converted value of the instantaneous traction force. He doesn't have a simulator
motor excitation shunting and motor group reordering have been implemented so far. The current indication is therefore
realistic only for DC series motors without shunting, the simulator also counts only one fictitious
"big" traction motor.

*** Forward speed = locomotive slide speed, indicated in the HUD or in the track monitor.
"Axle speed" = axle speed, converted to circumferential wheel speed. Indication indicated by the speedometer in
cabin.

It follows from the above that they have solved multi-system locomotives, various types of protection and drive chute.
The translation from the manual is machine, it may contain linguistic inaccuracies.

[Weter]

Here are some known examples with or without illustrations:
Case 1. The route is partially electrified.
http://www.elvastowe...ttach_id=108317
You can see 3kV DC electrified station and doubled contact wires, allowing to increase available current for powerful locomotives.
http://www.elvastowe...ttach_id=108400
And at the distant end of the station, electrified part of the route ends (you can see the black sign, prohibiting any further advance for electrified rolling stock, saying:
end of katenary !
If we define the route as unelectrified, we won't have any chances to see electric rolling stock in activities there.
If we will use auto-generated wire, it will follow all of tracks along this route and will look unprototypic, being single and thin.

Solution used: lifting of auto-generated wire to significant height (usually 500m) to make it "invisible"
Minus: electric rolling stock will be able to operate everywhere around the whole route.

[Weter]

Case 2. The route combines two or more electrification systems: 3kV DC, 25kV AC and, in future releases, AC 10(6) kV for quarry branches.
Saying about quarry tracks, it needed to note, that in addition to more lower voltage (powerful excavators and draglines are powered with AC 10(6) kV cables too there)
the contact wire placed with significant shift from the track's center line to allow cars loading by excavators or other mechanisms (e.g. stationary feeders)
For this reason, quarry electrohaulers have additionat devices for drawing current from such shifted contact wires. Or tractive aggregates are used (the MU, combining diesel-generator and power transformer-carrying sections along with motorized dumpcars in consist, suitable for autonomouse functioning on very steep And unelectrified quarry grades)
The south-west end of the route is at the station, electrified with 3kV DC
http://www.elvastowe...ttach_id=108439
The north-east end of the route is merged to mainline, electrified with 25kV AC
http://www.elvastowe...ttach_id=114001
That's why I mentioned, that it's nonsense - to put DC locomotive here, but in game, that's possible anyway.

As in previous case, the route is defined as electrified, the autogen-wires are lifted, any type of electric loco can go anywhere.

[Weter]

Case 3. Switching system routes.
To be honest, I haven't seen any of them, implemented in MSTS.
https://www.google.r...IWLJQapB0tvWrTO
The transition between different types of electrification in real life are made in two approaches, as far as I know:
- at the stretch.
For that, multi-system locomotives are used, and they are switched on-the-fly to different voltage/current type.
Some of them, by the way, are equipped with different pantographs for each of systems.
They can be used for the whole train ride, or for connecting two stations, which are the ends of parts, electrified in different standards.
- at the station.
For that, special stations are built, where contact wire above each of tracks can be connected manually or remote(by dispatcher-operator) to one or to other power supply.
So, it's obvious, that locomotives are being changed at such stations for continuing the journey of the train.

[Weter]

Another solution for case 1:
Author uses auto-generated contact wire, but performs the kind of cheat, replacing track sections of unelectrified part of his route with static objects.
This way, the wire over that "static" sections is no longer displayed, but the sections themselves are no longer "interactive", which means, the switches are no longer being animated.