[disc]

Today the modern EMU trains using regenerative (dynamic) brake as the main brake, by complemented with airbrakes if it's needed, but this method have been widely used on trams too, since very long time (since 1940s-50s)

These combined controls look like this: In one way it controls throttle, other way brakes, mainly dynamic brake. But as dynamic brake isn't capable to completely stop the train, airbrakes automatically used when the train is slowed down below the effective speed of dynamic brakes (below 5 km/h for example), to make it stop.
Is this possible now in OR? Or it will be implemented?

[jtr1962]

What you describe is called blended braking. It's implemented in MSTS, but the implementation isn't the same as how it works in real life. In real life the engineer calls for a certain amount of braking with the brake lever. The braking control system then determines what mix of air and dynamic braking to apply. Usually, there will initially always be a brief very small amount of air braking just to keep the brake shoes and wheel treads clean. After that, if the amount of braking the engineer wants can be provided only by the dynamic brakes, then the air brakes will be off. If more deceleration is needed than can be provided by full dynamic braking alone, then the air brakes will also come on. At low speeds the dynamics start to fade so the air brakes will come on more. In some cases they will also release slightly just before a stop to prevent jerking. For emergency braking ONLY the air brakes come on.

Of course, what I described is just a guideline. Every blended braking system is different. Modern equipment with AC motors can actually use just dynamic braking under normal circumstances. With DC injection you can even brake the train to a standstill and hold it in the station. The big advantage of blended braking, besides saving wear on the brake shoes, is twofold. One, in some cases regenerated power is fed back into the catenary or third rail and used to power other trains. Two, there is much greater braking control. You can increase or decrease braking force virtually instantaneously with dynamic braking. This makes precision stopping at station platforms much easier.

[captain_bazza]

Thanks for such a clear explanation how such a system works.

Cheers Bazza

[disc]

I knew this, but the question was is this possible in OR?

[jtr1962]

disc, on 21 April 2013 - 05:53 AM, said:

I knew this, but the question was is this possible in OR?

I don't believe OR has been programmed for blended braking yet.

[gpz]

Just a note: there is a bug report already submitted about this problem: Bug #1160292

[cjakeman]

gpz, on 22 April 2013 - 04:27 AM, said:

Just a note: there is a bug report already submitted about this problem: Bug #1160292

Bit hasty, Peter :-)

This Bug Report is about combined control (where throttle lever also controls braking), rather than blended braking which jtr1962 describes so well.

I have finished coding a fix to this bug but still have some testing to complete.