My loco instantly accelerates when I release the brakes

[JLD95]

Hi,

with scenario "The Rossington Run" provided with York-Peterborough route, I have a Class47 with 30 HAA Hoper. (I have AP Class47 Sound pack pro)
I brake gently and when I release the brake with no power on my Class47 and with a flat track, my speed train instantly accelerates from 20 to 30 mph !

It is possible to fix it ?

[rfletcher72]

Hi,

with scenario "The Rossington Run" provided with York-Peterborough route, I have a Class47 with 30 HAA Hoper. (I have AP Class47 Sound pack pro)
I brake gently and when I release the brake with no power on my Class47 and with a flat track, my speed train instantly accelerates from 20 to 30 mph !

It is possible to fix it ?

Bonjour Jean-Luc,

I think this a long standing bug which, to be honest I haven't seen myself for a while. I last experienced it on the S&C route and what I saw was that after slowing down, as soon as I released the train brakes the consist shot forward, gaining about 15mph in the process.

I gave up on the scenario at that point and have since then forgotten about the issue.

Not much help I am afraid, but hoping that others memories may be similarly jogged and a workaround posted ,

Bon chance,

[ttjph]

Previous discussions:

http://forums.uktrainsim.com/viewtopic. ... 1&t=126808
http://forums.uktrainsim.com/viewtopic. ... 2&t=135958

[ChrisBarnes]

That's a serious conservation of momentum bug deep within the core code, which I suspect is something to do with the repulsion of compressed couplings. One possible solution might be to tighten up all of the couplings used by the wagons in the train until there is negligible slack.

Another possible solution (which would make the brakes more realistic anyway) would be to script a very slow release of the train brakes on long trains, to minimize the surge. If, say, the control TrainBrakeControl was set with notches Release 0%, Direct >0-100%, and the player controlled the brakes via a VirtualBrake control, as the automatic brake valve (VirtualBrake) is moved to a release position, the TrainBrakeControl could be scripted to follow it at a rate dependent on train length and brake pipe pressure, so that the longer the train and the higher the brake pipe pressure, the slower the rate of release until the value of TrainBrakeControl matches the value of VirtualBrake. Similarly, you could smooth the brake application so that the higher the brake pipe pressure and shorter the train length, the faster the rate of application until the value of TrainBrakeControl matches the value of VirtualBrake, dependent on brake valve position (if the valve was put into emergency, you would want the rate of change to be much faster than just moving the handle through the self-lap position). Even better, as the value of TrainBrakeControl starts to close in on the value of VirtualBrake, decrease the rate of change. This would need to be done a per loco basis.

Chris

[JLD95]

thank you for your answers.

Problem solved by swapping Kuju HAA Hopper with WCML2 HAA Hopper: Keith M. Ross modified textures and physics