[SetiRich]

I've noted that when I connect the entire consist to my engine(s), the train line comes up to pressure quickly, but the aux & emergency reservoirs seem to take a while to come up to brake line pressure. Is there a restriction on the charging rate for the two car cylinders? I would think they'd all come to the same pressure as the entire train line came up. Why the delay?

[R H Steele]

Okay, I'm going out on a limb here, I am still learning brakes...are you using any of these ORTS parameters?

ORTSMainResChargingRate ( 0.4psi/s )
    ORTSBrakePipeChargingRate ( 200psi/s )
    ORTSEngineBrakeReleaseRate ( 38psi/s )
    ORTSEngineBrakeApplicationRate ( 34psi/s )
    ORTSBrakePipeTimeFactor ( 0.003 )
    ORTSBrakeEmergencyTimeFactor ( 0.1 )
    ORTSBrakeServiceTimeFactor ( 1.009 )
 	ORTSAirBrakeMainresvolume ( 28.35ft^3 )

Additionally are you aware of this document by Joe Realmuto posted here at ET >>> Guidelines for setting Open Rails Brake Parameters

[Genma Saotome]

I don't know much about charging, other than it is slow, but i do know a thing or two about what controls the rate and that is the size of the orifice that air passes thru, something that AFAIK is very, very small. Per the New York Air Brake Company, they describe the charging orifice on a #8 distribution value (in the locomotive; I assume the orifice mentioned here is to charge the air pipe on the train) as a #62 drill hole. That is a 0.038 inch diameter... a very tiny bit larger than 1/32 inch. If I am right about what's going on here then all of the air going thru this value goes thru that tiny hole.

Off hand I do not have any answer to how long it would take to charge a train line given that tiny hole (an answer would involve calculus as the rate would decrease as the line pressure goes up and I don't know how to do calculus, and besides, the length of the train line depends on how long it is so the total amount of air under pressure, in cubic feet (or some other UoM) will vary from train to train. I imagine a google search would turn up some useful information but I'll leave that to others.

The source I have in-hand (literally) says the AB brake valve "brake valve supply" orifice is 0.25 inch which gives another hint but that's possibly between the supply reservoir and the piston and not the brake line and the reservoir.

Another caution is that my source is perhaps 70 years old. While the physics of air under pressure has remained the same the length and weight of trains has not and so very modern equipment may require something different than whatever was right back in the day.

All the data I have from NYABC has been forwarded to Peter Newal of the OR team.

[Weter]

Quote

the rate would decrease as the line pressure goes up

That's why BP overcharge needed.
As far as We didn't have this capability in MSTS, the cheats in form of increasing release rates counter real values took place.
Good news: at unstable version the experiment of introducing overcharge token was commited.