Running brake/Self lapped

[CockneyRebel]

Can any of you explain to me please. In real life on a steam loco you only have a running brake or so I have been informed. So why do we have a self lapped position in the game ?

[Smokebox]

Well, "running brake" doesn't actually make much sense. Typically you have either vacuum brakes (normal on British steam locos) or air brakes (in North America). Within those two broad groups there's some variety in the way they work.

With regard to Westinghouse air brakes in North America (which I know more about than vacuum brakes), "Running" is a position on the 6-ET or 8-ET automatic train brake stand that is used to maintain the pressure in the brake pipe, to ensure that brakes stay released but without overcharging the brake pipe (a situation that can cause the brakes to be applied in a way that makes it very difficult to release them again). Release connects the brake pipe directly to the main reservoir, but Running connects it via the feed valve (which is set to maintain the correct system pressure in the brake pipe), which avoids overcharging. It's the normal position for releasing the brakes and recharging the auxiliary reservoirs ready for the next time you apply the brakes.

The steam loco 6-ET and 8-ET automatic train brake stands also have Hold and Lap positions:

HOLDING: Recharges the brake pipe to the feed valve setting and releases the train brakes, but holds locomotive brakes, if set, applied.
 
LAP: Closes all brake pipe connections. Holds the brake pipe at the desired reduction, but does not maintain it against leakage.

The independent brake (more properly called "engine brake") in a NA steam locomotive is usually an S-6 or similar. It also has positions for Release, Running, Lap, Slow Application and Quick Application.

RUNNING: Normal position to carry the independent brake valve when running. Releases an independent application of the engine brakes, but not an automatic or emergency application.
 
LAP: Closes all connections in the valve and holds the selected application of the engine brake applied. Unlike the automatic brake valve, this position will hold the engine brake cylinder pressure constant against minor leakage.
 

[CockneyRebel]

Smokebox,

Thanks for that informed response but I am still a bit confused. I work on a steam railway in the UK and one of our drivers told me that they do indeed have a running brake position ( UK steam loco ). My question relates to a UK steam loco in the game that uses a self lapped position as well. Is it maybe that the games hud is just set up that way or am I being a bit thick with my understanding of things ( or not understanding things to be precise ).

[GeneralGeldenhuys]

Originally posted by CockneyRebel:

Smokebox,

Thanks for that informed response but I am still a bit confused. I work on a steam railway in the UK and one of our drivers told me that they do indeed have a running brake position ( UK steam loco ). My question relates to a UK steam loco in the game that uses a self lapped position as well. Is it maybe that the games hud is just set up that way or am I being a bit thick with my understanding of things ( or not understanding things to be precise ).

I assume you are familiar with vacuum brakes. Well, the information on the HUD can be misleading, but from running the brakes seems to only to release when the small injector is turned on.

[Smokebox]

Originally posted by CockneyRebel:

Smokebox,

Thanks for that informed response but I am still a bit confused. I work on a steam railway in the UK and one of our drivers told me that they do indeed have a running brake position ( UK steam loco ). My question relates to a UK steam loco in the game that uses a self lapped position as well. Is it maybe that the games hud is just set up that way or am I being a bit thick with my understanding of things ( or not understanding things to be precise ).

I've had a browse on various technical websites and they appear to be saying that for vacuum brakes, there should only be Release (also called Brake Off), Running and Apply (also called Brake On) positions. Perhaps the loco with a self-lap position is just wrong and self-lap does the same job as Running, but I can't be absolutely sure about it. Another possibility is that Running in the sim doesn't do what Running does in real life, which is to hold the vacuum, but instead releases the brakes. If that's the case, maybe they've added Self-Lapping in the sim to do what Running should have been doing. You're right, it's very confusing.

Which steam loco is it, by the way?

[CockneyRebel]

All my steam locos and they all have both self lapped and running positions

And thanks again for your replies guys.

Dave.