Dodgy physics

[arizonachris]

Last two US diesels I've run were the SD70ACe, which only has a working speedometer (nice bunch of green displays that say "n/a", tho) and the SD40's on Rich's new Ohio Steel 2 route. Was driving out of the cab on that one so didn't really bother looking at the gauges in cab. And, no offense, I really don't run British stuff, except the Tornado, The Dutchess, and the Flying Scotsman.

BTW, Rich says he didn't do anything to the physics on the DMU's in his new route, but with two SD40's in front of a rake of loaded coal cars, it's a very different driving experience that I have been used to, to say the least. Longer to accelerate, and longer to stop by far. Didn't really pay attention to pressure, I was having to learn how to drive again. Oh, and the dynamics! Don't even grab more than 10%. Funny, you can hear them "spool up" as they engage. Don't remember ever hearing that before. Or maybe it's the fans? I dunno.

[TrainMaster1]

You will be thrilled to learn that I own no sim but my son who works on the project with has TRS, RW and MSTS. So please forgive my question as I do not need to own the sim in order to fulfill my role in every session. So I never think twice about what it has or not. Thought if it had that display it sure we be useful in knowing what to do in the game to get your desired effect.

Also if 10% of DB is too much either the physics really are way off or you are using them on flat ground on a light train. It's either that or a guy in a cape with a big "S" on the back is slowing your train down. Report him to the proper authorities for trespassing.

Nick

[Bart35]

Kali...Just wondering if you ever got around to uploading the latest break file?
Thanks..

[Kali]

Have to finish it first; given it all needs to be scripted now it's considerably more complicated. Also need to work out the best combination of what we have to represent what we need; I am pretty sure I can make you run out of air but it won't be quite the same as how the drivers have described it, because I can't put the full amount you release into the pipe *and* delay the train brake release, because the reservoir reduction is linked to the release itself, obviously.

[GaryG]

A thought, perhaps quite impossible but it might be do-able.

We have the script that passes the prime mover RPM info along the train. Could it be possible to have this script also pass braking info along? Yes, I realize all the rolling stock definitions (locos and cars) would require changes but this could buy us a few things not attainable right now.

The info passing script could perhaps pause for a half second or so before passing a changed value to the next car. If possible, this would now give us a propogation delay based on the actual consist rather than a fixed amount for all consists regardless of varying lengths.

Loco brakes could perhaps also depend on a passed value as well and ignore train brake values if dynamics are enabled and even better, the independent might be useable on all locos instead of just the driven loco. Along with independents operating on all connected locos, any seperated locos would not have the independent brakes operate if the car script didn't pass the independent info along; this would be fully prototypical.

All we would be missing now would be the bail off function which might be attainable if a key command could trigger a full brake release on all locos via the loco/car script.

We have some intelligent people here so look for your thinking caps, or even better, your beanies with propellers ;-)

GaryG

[Kali]

Maybe with handbrakes, that was something I always intended to try and never got round to it - thanks for prompting me about that - and also until it gets fixed, by abusing the dynamics and making every car an unpowered engine ( which I mentioned up the thread somewhere and is really not a good idea ). No go with train brakes, the whole consist is one with those. If you check the SD40 script it already tries to individually set the trailing engine's independent brake and that doesn't work at all. I also tried making a loco air-piped so it had no effective train brakes ( for bail-off, that was what I originally set out to do ) and it ended up still having train brakes, but no independent brake! you get some fun twilight zone moments doing this.

I think I will try the handbrake idea, I'm not sure if you can set a car's handbrake from script yet or if you can partially set it. The engine handbrakes are tied into the indy/train brakes too tightly so I think we still can't use those for engine brakes to get bailoff ( bailing off in this case would use air as it's releasing the engine's train brake ).

[PatrickL]

Okay let's clear up a couple of items.

#1 In the real world Independent brakes only apply on the first locomotive. Some games may have figured out how to get them to go to all the locos. That is not prototype. So if you want to run right...first loco only.

Ignore, looks like you corrected yourself on this mistake.

[Kali]

I just came across something talking about the FRED being able to release the brakes? is this a common feature or just something that certain ones do? and would any caboose have had remote brake gear fitted?

And while we're on that has anyone modelled one?

[MadMike1024]

I just came across something talking about the FRED being able to release the brakes? is this a common feature or just something that certain ones do? and would any caboose have had remote brake gear fitted?

And while we're on that has anyone modelled one?

FRED is radio controlled, and can be fired from the cab to dump the main air line. It's usually only used in an emergency, but it does have the capability. A friend who is a BN engineer described the drill for a vehicle or person on the track was as follows; Fire the FRED to dump air from the rear forward, cab lever to emergency to dump the air from the front, then honk the horn two long, one short, one long until the collision.

I don't believe there ever was a main air valve in a caboose. There was a pressure gauge for the cab crew to monitor the brake lines in case of a failure or disconnect.

I saw a FRED model on TrainSim, but don't know if it worked

[Dan]

In the UK brake vans do have the ability to drop the air/vacuum from the train.

To take the MK1 coaches in RW as an example. There you have slam door stock. So say the train is leaving and the guard notices that a door is not such properly. He can drop the setter and bring the train to an emergency halt. Likewise, if you have a request stop and the driver has forgotten.

Also, if the train was speeding or the guard felt that the driver might have fallen asleep, died etc etc, then the guard would drop the air. There was one accident in the UK where the guard realised the train was going too fast and dropped the air.

In pre-radio days (and still where you have no radio communication) tapping on the setter is a way for the Guard to contact the driver.

[GaryG]

I just came across something talking about the FRED being able to release the brakes?

Nitpick ... I think you meant apply the train brakes. A FRED has no capability to pump air into the trainline to release them, it can only adjust the trainline valve to either lower or maintain the pressure, the loco(s) must supply any air to actually increase the pressure and cause a brake release.

GaryG

[Kali]

Yeah - I was thinking about releasing pipe pressure and got the phrasing all mixed up. If a tiny little device stuck on a car could release the brakes all by itself there'd be none of this messing around running out of pressure :)

Although why you don't start using radio controlled brake valves and keep the pneumatic system as backup - or even use them on on car in 10 - I don't know. Not really an issue with our train lengths ( plus you'd have to really abuse a euro twin pipe train to run out of air ), but even here we tend to use EP brakes for passenger trains now.

[Dan]

I don't believe there ever was a main air valve in a caboose. There was a pressure gauge for the cab crew to monitor the brake lines in case of a failure or disconnect.

This image appears to show levers/valves connected to the pressure gauge

[Kali]

Gauge test on the right, and that has to be a train air valve on the left. It wouldn't really make any sense to leave one out. I would imagine emergency use only though!

[Dan]

But it makes sense. If the job of the guy/girl in the caboose was to check for hot boxes, slipped loads etc etc, then you would on occasion need to make an emergency brake application.