Dodgy physics

[Kali]

I believe the handle for the loco brake goes left and right to apply or release the brakes, and can be pushed downwards to bail them off.

Well, don't know of any model with a handle like that, but if I can ditch the train brakes from the engine then just moving the loco brake would have to do - you'd have to put it in 0 and then the auto brake in 0 also to re-synch them. But procedures? anything special to do first?

[TrainMaster1]

I am loving this discussion as I am always interested in seeing people interested in running according to prototype. Great info that is spot on for minimum application pressure etc in your post Toripony. We teach that and much more in our Intro Events when people come to learn how to run in our prototype sessions. It makes a big difference in your enjoyment of the game when you are running correctly on a good route with actual consists from the 1:1 real world counterpart. That is what we will be starting very soon for RW in November. So anyone interested in prototype running and operations, I invite you to drop in to listen our session on 10/29. In this session, we will be running the CSX Kingsport Sub recreating many of the exact consists from May 5, 2011.

We can do this for any sim where the route is a faithful representation of the actual Class One route. Working with our RW members now at our forum to select routes, map them and have them ready to start sessions next month. If you are interested, and want to stop by on 10/29 (send me a PM and I will show you what you need to do.) Then if you like the session enroll in our November Intro Events and mini sessions for new road crews. This will allow you to run in our RW operating sessions. So come on and see what it is like to run on an actual railroad with correct consists, actual operating rules, live dispatchers, yardmasters, trainmasters and more. I can guarantee you will enjoy the experience and increase your enjoyment of the sim big time.

Thanks for reading,

Nick

[Toripony]

This might lend some support to "Point 1"... the difference in resistance with the train brake on changes drastically when one uncouples from the train. In other words, set 14 lbs of brake on a 10 car train, a 50 car train, and a 100 car train... disconnect your locos from the train with that brake still set... you take off running, right? Just anecdotal evidence, but I have wondered if I'm looking at the wrong culprit for this entire problem.

Interesting braking technique there on Donner Pass. I've looked many times but could never tell exactly how the Ronceverte pusher operated on the coal drags here; the couples are neither bunched nor stretched.

I think Adam is aware of this issue; I'll see if I can invite him to this thread. I want this not only for myself but because a lot of RW/TS players are missing out on one of the most important aspects of driving a locomotive.... braking techniques. None of us has experienced the cresting of a steep mountain that immediately descends on the other side and you have 80 cars of train pushing you, 80 cars still being pulled, and maybe pushers on the back... the speed limit is 10mph and you're trying to drop off your pushers and set 6 lbs of train brake without stalling and all this within 1 mile! (that's what they had to do at Alleghany) Actually, I have experienced it; it's fun and really hard. Harder driving than I want to do, to be honest...

[Toripony]

Thanks for adding to the discussion, Nick. Thinking about VRR running on the COA is another reason I hope this issue can get some attention. Personally, I would like to join one of your sessions just to listen and learn how it's really done. I know very little about the engineer's job or train dispatching. Knowing those things helps me design more realistic scenarios. Unfortunately, I will be offline a lot in coming weeks so I'll have to catch one of your sessions this Winter.

Btw, there's another rule about the eastern Alleghany grade in the books that's very interesting. Essentially it says if you stall the train going down the mountain, enough hand brakes must be set to hold the train. Once you release the train air brake, the pipe must be recharged for 45 minutes or to 50% of the pressure you had when starting down the grade at Alleghany but not less than 55 lbs. I don't really think I'd WANT to simulate THAT or we would never get to finish our scenarios... .

[TrainMaster1]

No problem, Toripony. In our sessions we use the actual rule books and TTs for every road and route we run. So when there is something special in terms of operations we do it. There is a quite similar rule on lots of the mountainous coal route in the east. Like the Pocahontas division on NS and its torturous brake test to get clear to move a train out of Bluefield towards Williamson. Lots of rules for number of handbrakes to set and holding the train in place with a service application before you get a clear from the DS.

For instance we were instrumental in developing the Horseshoe route for MSTS for layout, operating speeds and rules. It makes it so much more fun to run when it is done right. Right down to TOB ratings on The Slide and all speed zones on the hill. Still waiting for someone to do a version that goes from Conway to Altoona or even better to Enola. Then we could use that route in a session. Both the MSTS and RW versions are way too short and wide to make for a good session.

How long is the C&O route that you have? What era is it set in? How close is it to the actual prototype? Just looking to see if we can use it in an operating session at some point.

Nick

[Kali]

One more question, if anyone knows? does the loco brake handle as modelled on say, the SD40, work right? Is it really a lever that if you move it to say, 75% then the loco brake will come on until it hits 75% and sit there... or is it a lever that if you move it to 75% and leave it the loco brake will come on at half speed until it's on fully? ie, forwards - add pressure, middle - keep current pressure, backwards - reduce pressure.

[Kali]

Hmm, I declare a loss, unfortunately. It would appear the train brakes will control the engine brake cylinders no matter what - I have even set the train brakes to air-piped right now and with the engine on it's own and the engine-only brake locked at 1%, a full-service app will stop the engine very quickly. I guess we're going to have to put that in the "not working right" bucket with steam engine steam brakes for now. The irony of all this is I have no loco brakes at the end of it all!.

[bitchinbetty]

That is perhaps the reason these such engines have a bail off function do drop pressure on engine brakes while maintaining pressure on the train. Hence you can stretch the train out.

Not modelled in TS unfortunately.

[TrainMaster1]

There are three types of brakes on most US engines. All have two of the three. Here we go:

1) Independent Brake: operates only on the locomotives and is generally used in low speed switching. Although I have seen poorly designed engines in all sims that seem to have superman strength independent brakes that can stop a speeding train. The independent should work on all engines in the consist but on certain sims it only operates on the first loco and treats the other engines as if they were cars in the train. This brake does not directly apply air to the cars in the train.

2) Automatic Brakes: This applies air to the cars in the train and is the main brake you should be using while running. Note that frequent applications and releases will cause you to have to wait for the air to recharge so that the next application can be made. This is where engineers get in trouble in sims especially on downhill runs. Until you are at the bottom of the grade you should be running with a minimum application and pull against that where needed on short stretches where a grade levels off. When the downgrade resumes, reduce the throttle, set up your dynamics and get ready for the leg of the run.

3) Dynamic Brakes: This basically turns the traction motors into big fat resistors and creates drag to slow down the train. This process creates a tremendous amount of heat that needs to be vented away from the traction motors. That is why you see those fans and blisters at the roof line of many engines as this is where the heat created while in dynamic braking mode gets vented away.

To run correctly you need to know when and how to bunch slack to start upgrade, to start down grade and keep the train under control. Having run in both passenger and freight service, most sims do not always accurately portray this phenomenon virtually leaving many scratching their heads as to why an activity or can't be completed.

This is just one of many prototype items we cover in our Intro Events and operating sessions where we train you to run just like the 1:1 scale guys do. Not only will you enjoy working on a railroad but even when running on your own outside of a session you will have a much better understanding of what it is like to be in the cab of an actual locomotive.

Hope this helps.

Nick

[MikeK]

Since you mentioned dynamic brakes, I want to mention that we desperately need a notched "setup" position. That way you can go from applying braking force to basically "neutral" and back without having to go through the 10 second waiting period each time. Using either the keyboard or mouse, it is hard to reduce the dynamic brakes enough without accidentally going back to "0", then having to wait 10 seconds to add brakes again.

On a related note, I have noticed that when you save a game, it saves all the control positions, but doesn't save the engine rpm or force levels. So if you are coming down a hill with dynamic brakes applied, save the game and reload it, instead of it coming up with the dynamic brakes still applied, only the control position is correct. You now have to wait 10 seconds before the dynamic brakes start applying any force! On a steep grade you end up gaining a lot of speed before you can get the thing under control.

In other words, the only time you can save the game and expect to come back in and pick up exactly where you left off is when all the controls are at "0"! If you were under power you have a few seconds while the engine spools up to get back to where you were, and if you were in dynamic braking you have at least 10 seconds until it gets back to where you were. This kind of defeats the purpose of being able to save at any time.

[Kali]

Notched dyna brakes I can do, I think. How many notches would you like? ( for a SD40 still, given that's what I'm messing with ). Saved games I don't think I can do anything about, it only saves the positions of controls ( if you see them or not ).

[GaryG]

Hi

Just a thought about the Dynamics being only effective in the Player loco (I've read, not confirmed).

Would it be possible to set them up to pass the variables info along the train using the same method used to pass the throttle setting to all locos?


As for how many notches - I looked at an online SD40 manual and in that manual a control seperate from the throttle had a DB position. When set it modified the throttle action to control the actual dynamic braking amount; when in DB mode, notches were disabled.

The seperate DB control we are used to seeing in MSTS/RW might have been an added option or later version.

GaryG

Note:
The manual I looked at was: http://www.kirara.co.uk/info/SD40%20-%2 ... %20Manual/

[TrainMaster1]

On most locomotives with a control stand the same number of notches (8) are the same for the dynamics. So you would have 12% in notch one 25% in notch two if you are trying to do it realistically. This is done on a loco by coming down to power notch zero, then either hitting the selector or dynamic set up and notching out accordingly.

Desk Top controllers also have a combined power handle in many cases and the 8 notch rule still applies. So if you are wanting to run accurately that is the way to go. It is your choice but that is how it would work in the real world.

Just remember DB only works on the engines and on steep grades you will still need air behind you to control the train. This gets easier if you have DPU on your train (Distributed Power Units) which are controlled by the lead loco. This makes starting, stopping and controlling trains on any kind of grade much easier provided the physics are done correctly on the equipment.

I also know in MSTS that DB works on every engine regardless of placement so every loco goes into Dynamic mode at the same time. Not sure about RW though.

Nick

[Kali]

Hi

Just a thought about the Dynamics being only effective in the Player loco (I've read, not confirmed).

Would it be possible to set them up to pass the variables info along the train using the same method used to pass the throttle setting to all locos?


As for how many notches - I looked at an online SD40 manual and in that manual a control seperate from the throttle had a DB position. When set it modified the throttle action to control the actual dynamic braking amount; when in DB mode, notches were disabled.

The throttle is passed along automatically. The dyna brake handle is set up to do that already anyway but if it's not working then it might perhaps be worth having a go at scripting it by passing the value along like we used to do for RPM, and then attempting to set the brake with it. Note that this is all new RW3 ground so I have no idea what will happen... it may be that trailing units simply don't have dyna brakes whatever you do.

Combined power/brake control is possible, actually; the dyna handle would have to be reused as an on-off switch and it's a bit big for that really, but it's certainly doable.

I will attempt to give the handle however many notches the power controller has,then.

[Kali]

Okay, got a few things installed - I will probably have another go at some stuff when I can read the manual properly ( like the switchable power/brake handle version ).

File attached.

* Notched dyna brake handle - I'm pretty sure someone asked for this but now I can't remember! it's an option anyway.
* I did attempt to set the trailing unit's dyna brakes in script, I'm totally unsure if it's worked! seemed to slow my test consist slightly more, but I could just have been seeing things.
* Auto brake has no min reduction & a much bigger range of movement, so you can add just a few PSI.
* Dynamic smoke out of my old stock script that depends on power rather than TE ( which is a daft thing to use for smoke ). Colour needs work but not relevant.

There's a new SD40 Black Dynamod, so if someone with time could play with combinations of it ( and the default units also ) and dyna brake settings to see if it did make any difference in multiple, I'd be pleased to hear results.