[copperpen]

You don't really need the engine brake BC to show, just the percentage of brake applied and it should show at all states of brake position. What is needed is the separation of the train brake from the engine brake in that the train brake BC should only reflect the train status, excluding the engine, but including the tender.

[steamer_ctn]

copperpen, on 18 March 2016 - 03:51 AM, said:

You don't really need the engine brake BC to show, just the percentage of brake applied and it should show at all states of brake position.

IMO, for consistency, either BC or percentage should be used for both lines (train and engine brake).

I would prefer BC as this is a pressure value, and more reasonably aligns with the values that a driver would be used to working with rather then percentages.

[atsf37l]

copperpen, on 18 March 2016 - 03:51 AM, said:

You don't really need the engine brake BC to show, just the percentage of brake applied and it should show at all states of brake position. What is needed is the separation of the train brake from the engine brake in that the train brake BC should only reflect the train status, excluding the engine, but including the tender.

No, that's not exactly true. I'm talking about an application of the train brake without any direct application of the locomotive brakes. When you bail off the driver brakes - engine and tender brakes as the software is currently configured - the only indication you get on the locomotive brake line is "Release." "Bailing" flashes momentarily while you are actively bailing off the engine brake, but the percentage of the engine brakes applied by a train brake application is not shown there, only in the train brake line. Only if you apply the locomotive brakes separately do you get a percentage display but normally the loco brakes aren't applied, only the train brakes and when you bail off you get no such separate percentage.

[copperpen]

As the locomotive independent system takes air direct from the reservoir at full pressure, the BC pressure is controlled by the independent brake handle and is therefore a percentage of the handle movement. Looking at the screenshots provided by Peter, it seems like there is a bug in the code as running position should be showing 0 BC not 14psi. In fact, should there even be a Running position on an engine brake, after all, it is either on or off, nothing inbetween.

[Genma Saotome]

What Herb says.

One thing I'm curious about... all of the .eng files I look at say there is a triple value on locomotives. I know that's not right for steam... I dunno about diesel. Has anyone removed that item from their .eng file? What happens?

[gpz]

Genma Saotome, on 19 March 2016 - 09:43 AM, said:

One thing I'm curious about... all of the .eng files I look at say there is a triple value on locomotives. I know that's not right for steam... I dunno about diesel. Has anyone removed that item from their .eng file? What happens?

Do you mean "triple_valve" in Wagon(BrakeEquipmentType()) ? It doesn't make any difference in OR.

[Genma Saotome]

gpz, on 19 March 2016 - 10:35 AM, said:

Do you mean "triple_valve" in Wagon(BrakeEquipmentType()) ? It doesn't make any difference in OR.

Yes I do. Why does it make no difference in OR? Seems to me the lack of that equipment on a steam locomotive would make a huge difference when the brake cylinders begin to release.

[copperpen]

With my test train looking at the train braking info page while applying the brakes, the cars say apply in the triple valve column, while the engines say Lap. That is with or without the Triplevalve references in the eng file. The engines will have exactly the same BC as the rest of the train up to the max brake pressure of the cars. In my case this is with 70% of the brake applied. Full engine BC is reached at full brake application (100%)
This puts the engines BC at 70 and the train BC at 50. When releasing nothing happens to any BC until the brake reaches 38% at that point the engines release a BC of 34 with train BC still at 50. Continuing the release, engine brake BC gradually comes down to 13 at 2% brake when the train triple valves go into Lap with BC still at 50. At 0% brake all start to release with the engine brakes coming off first.

[steamer_ctn]

copperpen, on 19 March 2016 - 02:25 AM, said:

In fact, should there even be a Running position on an engine brake, after all, it is either on or off, nothing inbetween.

The brake system that is modeled in the screenshot is based upon an A-6-ET brake system, which is described on this page. In particular, the Westinghouse publications describe the valve positions for the brake(s) control valve, and brake valve position diagrams are shown midway down the page. The publications indicate on this type of brake valve both the train and independent brake had five (5) operating positions, and suggested that it was possible for the engine brake to be set to specific values.

As has been agreed (?) by most participants there appears to be a need to differentiate between the pressures applied to the train brake and the engine brakes.

[Genma Saotome]

steamer_ctn, on 19 March 2016 - 01:58 PM, said:

As has been agreed (?) by most participants there appears to be a need to differentiate between the pressures applied to the train brake and the engine brakes.

Yes.

What seems tricky tho is what Herb has been nudging into the conversation: Apply the Automatic brake and watch the BC on ALL UNITS apply. Hit the bail off and the locomotive brake cylinders will vent to the atmosphere w/ apparently no effect anywhere else. Release the automatic brake to return everything to normal... now hit the Independent Brake. The locomotive's brake cylinders take on pressure and apply the locomotive brakes. No effect anywhere else. Straight air... apparently no triple valve here. Apply the automatic brake... all down the train line cylinders kick into action. Here is where it is not clear to me: if the Automatic brake is applied to a greater extent that the Independent, will the effect creep into the locomotives brake system? I think so but I do not understand how given the locomotive does not have a triple valve.

Herb? Help.