[Traindude]

HI:

I recently downloaded a commuter cab car that I converted to make use of ORTS' new unpowered control car parameters. However, when I run a cab-car-first consist, I encounter a problem: When releasing the train brakes, the brake cylinder pressure reduces to zero, but the brake pipe doesn't get to maximum pressure. On the extended HUD (ALT+SHIFT+F5), the main reservoir pressure for the locomotive on the opposite end of the consist doesn't go below maximum, nor does the compressor kick in.

What am I doing wrong?

[darwins]

1. Are all the vehicles in the train set as "Air Twin Pipe"? This is important as the air needs to be supplied from the compressor and main reservoir to the commuter cab car. (If the brake system on the car operates only as a single pipe system use this setting:

BrakeSystemType( Air_twin_pipe )
ORTSMainResPipeAuxResCharging(false)


2. Be aware that control car code is still in development. Some things do not work yet.

[Traindude]

darwins, on 07 April 2023 - 12:06 AM, said:

1. Are all the vehicles in the train set as "Air Twin Pipe"? This is important as the air needs to be supplied from the compressor and main reservoir to the commuter cab car. (If the brake system on the car operates only as a single pipe system use this setting:

BrakeSystemType( Air_twin_pipe )
ORTSMainResPipeAuxResCharging(false)


2. Be aware that control car code is still in development. Some things do not work yet.

I'll try that, but IIRC, some cab cars (such as the Bombardier Bi-Levels here in North America) still use single pipe systems.

[darwins]

Weter, on 07 April 2023 - 12:01 PM, said:

That must be a workaround for now.
I wait for pure single-pipe option too!

Please explain how pure single pipe can work?

An actual brake valve in a control cab must be supplied with air from the main reservoir by a reservoir pipe in order to be able to release brakes.

The only other option I can see is for the control car to electrically or electronically operate the brake valve in the locomotive. In that case of course the brakes would always be released from the locomotive end first regardless of the direction of travel of the train.

[Weter]

This is very fair question, since it's quite hard to define: consider or not as a part of train brake system the main res pipe, connecting all main reservoirs of EMU train and supplying with air all equipment of the trainset, including brake valves, but having connection with brake pipe only in two points: in each cabs.
Most often, compressor and main reservoir itself are mounted on head cars of EMU, then - on each of cars (subway), or on trailing cars (commuter trains).

But I must admit here: I occasionally have pulled this discussion off it's topic, as it's not about push-pull trains, powered by locomotive on one of its ends.
In this case - no compressors on control cars are very likely (may be additional MR, though, as Laci said)
But main feature is still that MR pipe has nothing with WAGON part of brake systems: it is being not connected to distributors for direct filling auxiliary reservoirs or brake cylinders, so it's needed only in control part of the system - being connected to brake valve (controller) in cab.

In other words, design of brake system itself is single pipe, air supply of controller is always the pipe, connecting it to MR, either being on this unit, or no.