[Csantucci]

First interventions:
- with x.3930 the bug in the calculation of the MSTS-like dynamic brake force table has been corrected, and parameter DynamicBrakesEffectAtMaximumFadeOut is taken into consideration
- with x.3931, only if the option "Correct questionable .eng parameters" is checked, parameter DynamicBrakesDelayTimeBeforeEngaging is set to 2 seconds if the locomotive is electric and such parameter was > 4; again only if such option is checked, parameter DynamicBrakesMaximumForce is set to 0.5 of MaxContinuousForce if it had a too low value in comparison to MaxContinuousForce (as the one of the HHP8). In fact very often such value is set to 20000, because it is the suggested value in the original MSTS Eng_and_wag_file_reference_guidev2.doc document, and such value is too low for the majority of locomotives.

Further interventions are foreseen.

[hroch]

Hi,

eugenR
Comparison of traction force versus dynamic force is in my post 17 c) at the bottom of the page http://109-e.wgz.cz/...-tech-parametry

[Csantucci]

To reduce the problem of having low dynamic braking forces during bailoff, attached is a patch file for x.3931 that performs autobailoff only if the max dynamic brake force at that speed is higher than 60% of DynamicBrakesMaximumForce. Pls. comment on it. In my opinion it is a step forward driveability.


27/8/17: attachment deleted because patch uploaded in x.3934

[eugenR]

Csantucci, on 24 August 2017 - 01:30 AM, said:

To reduce the problem of having low dynamic braking forces during bailoff, attached is a patch file for x.3931 that performs autobailoff only if the max dynamic brake force at that speed is higher than 60% of DynamicBrakesMaximumForce. Pls. comment on it. In my opinion it is a step forward driveability.
Orts.Simulation.dll.zip

Salü Carlo,
I have tested it works. I have tested with and without Brake-Option, no differences, correct?
one speed area is suprizing:
I start up to 50MPS, pull the brake to 30%, then the dynamic brake will be activated until the speed is down to 15MPS, then it switch back to the Trainbrake, and that with this low force dynamicbrake of the Original-Eng-File ?
DynamicBrakesMaximumForce( 20000 ), the same if I reduce this to 10000 kN edith: and to 100 kN
can you see any reason?

regards
EugenR

[Csantucci]

Eugen,
in my patch the check whether to use the dynamic brake or not in case of autobailoff is not based on an absolute value of the dynamic brake force, but, as said in my previous post, on the comparison of the dynamic brake force at that speed with DynamicBrakesMaximumForce * 0.6. So reducing DynamicBrakesMaximumForce does not change the comparison, because also the dynamic brake force at that speed is reduced proportionally.
The check is done so because it is intended that DynamicBrakesMaximumForce has a reasonable value. If it doesn't, the "Correct questionable .eng parameters" has to be used.

In case of the HHP8, if you don't check "Correct questionable .eng parameters" you have two effects: DynamicBrakesDelayTimeBeforeEngaging will stay at 10 seconds and the dynamic brake will have less effect, because DynamicBrakesMaximumForce will stay at 20000.

[Csantucci]

I've further checked the original code. Such code has introduced one new (I suppose barely known) optional parameter: OrtsDynamicBlendingForceMatch: if this parameter is set to 1 (true) in the .eng file, the code seems to automatically adjust the Dynamic Brake force to the desired brake force value. The default for this parameter is 0 (false). In fact this parameter is commented as follows in the code: "if true, dynamic brake blending tries to achieve the same braking force as the airbrake would have." Do real locos behave this way? Would it maybe better if the default for this value was 1 (true)? Nice if someone could check the effect of this parameter.

hroch, on 22 August 2017 - 11:56 PM, said:

https://youtu.be/6Ua7T_GRjCM
Sigle pipe, when dynamic brake stops working, brake cylinder is not filled up air. If he applies brakes again from, the pressure in the brake cylinder doesn't increase anymore. It stays on 0 bar. This doesn´t work corretly in OR. Because the pressure in the brake cylinder grows up and then goes down. Time 0:55s.

I've checked this, and in fact it should be corrected.

[eugenR]

Csantucci, on 24 August 2017 - 05:55 AM, said:

Eugen,
in my patch the check whether to use the dynamic brake or not in case of autobailoff is not based on an absolute value of the dynamic brake force, but, as said in my previous post, on the comparison of the dynamic brake force at that speed with DynamicBrakesMaximumForce * 0.6. So reducing DynamicBrakesMaximumForce does not change the comparison, because also the dynamic brake force at that speed is reduced proportionally.
The check is done so because it is intended that DynamicBrakesMaximumForce has a reasonable value. If it doesn't, the "Correct questionable .eng parameters" has to be used.

In case of the HHP8, if you don't check "Correct questionable .eng parameters" you have two effects: DynamicBrakesDelayTimeBeforeEngaging will stay at 10 seconds and the dynamic brake will have less effect, because DynamicBrakesMaximumForce will stay at 20000.

Seen, but I use the following conditions:
X3931+Patch
unchecked questionable Brakeparameters
DynamicBrakesMaximumForce( 100 ) !!
Start to 50MPH
Train Brake 30%

After 10s switch to dynamic Brake, but with reasonable brake force good so but why, has you that planed???

[Csantucci]

Eugen,
the logic is: OR uses in good faith the parameters present in the .eng files. If they are garbage, they should be corrected or the "Correct questionable braking parameters" should be checked. This is so also with the other braking parameters that are handled by the "Correct questionable braking parameters" option.

[eugenR]

Csantucci, on 24 August 2017 - 06:55 AM, said:

Eugen,
the logic is: OR uses in good faith the parameters present in the .eng files. If they are garbage, they should be corrected or the "Correct questionable braking parameters" should be checked. This is so also with the other braking parameters that are handled by the "Correct questionable braking parameters" option.

Carlo,
Then the above is also OK.
Now this new Parameter OrtsDynamicBlendingForceMatch( 1 )
for me it works perfect. In the F5 Force Information the TOTAL is showing the same Valor if set to 1 independent of the working braketype, until the Engine has stopped.

Yes I think also this parameter should be default = 1
In modern Trams the driver set for a Stationstop the Wheel on Brakeposition 2 and the car is bracking with the same force until stop independent of the used Braketyp. this I have also seen some days before with older releases.

And a new detection:
If the Engine has more than 65 MPH and I set the Brake to 30% the dynamic brake will never be activate until the engine has stopped??
This I have also seen some days before with an older release.


Regards
EugenR

[Csantucci]

The OR problem described by hroch is following one: suppose a locomotive with autobailoff is running at 130 km/h, and that the autobailoff is active between 30 and 80 km/h. A locomotive with double-pipe airbrake behaves as follows: when starting braking the brakepipe reduces pressure, the triple valve goes to Apply for short time (it goes to lap state then), the auxiliary reservoir maintains its high pressure, the brake cylinder increases pressure and the locomotive brakes. When arriving at 80 km/h the BC reduces pressure down to 0 and the dynamic brake starts operating. When speed is down to 30 km/h the triple valve shortly goes to Apply again (because the brake pipe pressure is lower than the auxiliary reservoir pressure), the brake cylinder increases again pressure and the loco brakes again with its air brake down to 0 km/h.
With a single-pipe locomotive instead, when starting braking the auxiliary reservoir reduces its pressure together with the brakepipe pressure; this is not a problem until the speed is down at 30 km/h. At that pont the triple valve isn't able to go to Apply, because brake pipe pressure is not lower than the auxiliary reservoir pressure, and so the brake cylinder doesn't increase again its pressure, and the locomotive decelerates very slowly down to 0 km/h.

So my question is: how should the above single-pipe loco brake parameters behave in this process, so that the air brake intervenes again increasing pressure in the BC when the dynamic brake force fades out?