[Csantucci]

I have noticed that on our italian DMUs, that use EP brakes, braking stops the train very, very slowly, and much slowlier than MSTS. So I tested the standard Kiha31a DMU, and got the same effect. Has someone other noticed this effect? May I have a comment from the OR developer of this function (maybe Matej)?

[Matej Pacha]

Hi,
I'm afraid I'm not able to answer. The brakes code has not been changed for a while and the author is passive/consultant now. I can see some issues in the braking system, like:
- if you uncouple some cars, every uncoupled car would have the braking line disconnected and would start to brake, while the player-connected cars would continue as if nothing happened.
- every car has a single-ended brake pipes, what is not correct, since every car has front and rear end
- the player locomotive brake system is always full when you connect hoses

Unfortunately, my time is very limitted these days. What more, the only information I have on how it should work is the Manual 2.0 by Rudolf Richter with many questions not answered.

Cheers,

Matej

[Csantucci]

Matej, thanks for your time. I have decided to change brake type for the DMUs, using more the more standard standard generic single pipe type. This solves my problem

[Lindsayts]

Csantucci, on 16 March 2014 - 01:07 PM, said:

Matej, thanks for your time. I have decided to change brake type for the DMUs, using more the more standard standard generic single pipe type. This solves my problem

Twin pipe braking was working OK last time I tried it (V2084).

Lindsay

[jtr1962]

I think the issue here might be that blended braking isn't set up. I recall the same issue in OR with some EMUs. I remember setting them up in MSTS with blended braking and also making the air braking values low. Dynamic braking provided the bulk of the stopping power. The reason I did this was to get a variable deceleration rate like the prototype (i.e. 1 mph/sec at 70 mph or above, increasing to 2 mph/sec at a lower speed). Air braking provided only about 0.5 mph/sec. I varied the dynamic braking curve so it increased from ~0.5 mph/sec at 70 mph or above to 1.5 mph at lower speeds. Unfortunately since blended braking isn't implemented yet in MSTS these EMUs decelerate very slowly.

One workaround I did on units with combined controllers was to make the braking portion of the controller control dynamic braking instead of air braking. I then adjusted the dynamic brake curve to apply ALL of the needed deceleration.

And yes, twin pipe works OK for me as well.

[disc]

How EP brakes are connected to blended braking? Totally different problems.

[jtr1962]

disc, on 17 March 2014 - 01:26 PM, said:

How EP brakes are connected to blended braking? Totally different problems.

Blended braking and EP brakes are sometimes used together. The EP brakes in the Series 2000 work fine for me. They do apply a bit more slowly than in MSTS, but I ultimately end up with similar deceleration rates. That's why I'm thinking maybe the problem here is related to blended braking.

[Csantucci]

I found out the critical parameter for OR EP brakes: it's TrainBrakesControllerFullServicePressureDrop( ) .
This parameter is used by OR as the the maximum pressure that can be applied to the brake cylinder (or of it's equivalent?), and in fact it's the value I see after BC in the HUD display when at full braking. Due to the fact that in standard trainsets, like the Kiha, this parameter is set to 26, that is much below BrakeCylinderPressureForMaxBrakeBrakeForce( 70 ), the trainset brakes very, very slowly. Increasing TrainBrakesControllerFullServicePressureDrop( ) up to the other parameter did the job.
I wonder if it is correct that OR uses TrainBrakesControllerFullServicePressureDrop( ) this way.

By the way I'm not an expert in braking systems, but I don't see relationships between the EP braking system and the double-pipe system that someone mentioned above.

[PA1930]

It depends on what trains have it equipped like that, Carlo.

For instance, the Portuguese renewed Sorefame cars and Corails use twin pipe system as well as EP braking, though only with a loco that has EP available (and if EP isn't available, the trains are limited to 140km/h instead of 200km/h of their regular speed).
What happens is that all the consist can apply the brakes quickly as soon as the train driver applies it on the locomotive with the EP system. If this isn't available, to give an example, the last car might not brake as much as the first ones do because of the air distribution takes some time to provoque that "different balance" on when taking out air (in air compressed braking, I mean) from the braking cylinders.

Disclaimer, I might have said something wrong so if anyone has a better explanation, please correct me! :) But that's what I know from memory. Hope it helps a bit... :rotfl:

[dennisat]

Csantucci, on 19 March 2014 - 06:51 AM, said:

I found out the critical parameter for OR EP brakes: it's TrainBrakesControllerFullServicePressureDrop( ) .

I've found that raising this value until realistic braking effect is obtained in OR doesn't seem to affect the way that the braking in MSTS responds.

Dennis