View Full Version : Dynamic Braking?

November 20th, 2006, 09:58 PM
Do they dynamics even work in Trainz? I've tried them on a few different locos, with no apparent effect. If there is, is there any way to maybe turn the power up? It would be nicer than riding the train brake all the time down a hill.

November 20th, 2006, 10:23 PM
I take it you drive in cab-mode, press "C" the "throttle" in the hud turns red, the you go up the throttle notches until you get the braking-force you want. However - not all loco's have dynamic braking, it depends on the engine-file.

Which loco's exactly have you tried ?

November 21st, 2006, 12:42 PM
Hi guys,

I tried this too, and discovered same thing. Im using cab controls witch mouse. I tried it on VMD WC F45 (cab aliased from UP DD40). Dynamic brake lever have three positions, I tried it with 2nd and 3th position (used throttle lever as brake), but no efect. I was on 2percent grade, 3 engines and 35 cars.
Im not sure, but real F45 have dynamic brakes I think.

November 21st, 2006, 01:18 PM
:cool: In the engine config file dot txt, there maybe a dynamic brake script.

Two percent is a dastardly grade...dynamic braking is not a stop on a dime thing.

Dynamic braking is limited to speed, which includes distance, and may be supplanted by air brakes-usually the locomotive brake is bailed off.

F45's did not necessarily have extended range dynamic electric braking...

Dynamic electric braking, has a subtle effect. It's like slowing the train down, instead of stopping, as with air braking.

November 21st, 2006, 06:34 PM
Yeah, subtle it is. On a 2% down-grade 35 cars is going to push on a lot. Depending on the weight of the cars, the train might even accelerate eventhough you have 3 engines on full dynamic braking.

F 45:s had potential dynamic braking. If the WC-one had I don't know, ask the fellows at trainzlocomotiveworks/wisconsintrainz. In CMP you can check the enine-file without open-for-edit by right-click and "view config file". Scroll down passed the throttle to see if it has dynamic braking. The left column is meters/second the right column is deceleration force.

November 21st, 2006, 09:15 PM
But in Trainz does more locomotives increase braking power?
Plus, 35 cars and 3 locomotives for breaking should be a piece of cake. On the CP Mountain Sub over Rogers Pass, 3 AC4400s take 100+ coal loads down the pass

November 21st, 2006, 10:42 PM
Yes it should but it depends on if the engine-file is prototypical or not even close. I've seen some engine-files that are completely of the scale. Also is the mass set correctly for the loco and cars in the config - seen some bad examples there too.

In the end this is just a sim and has its limitations as for accurate physics. The mass contra acceleration-force is counted for but become less accurate with very heavy locos/trains and needs to be compensated for. It takes trial and error to tweak these things but it's possible. Your own experience with real trains also helps ofcourse. Horsepowers and weight is not everything - tractive effort is more interesting but hard to translate to Trainz. Therein lies the challange.

Have you tried weevil's engine-files at DLS - called T3P kuid:9000 ?? If you don't want to make your own, try them out, they are very good.

November 21st, 2006, 11:07 PM
Most of my downloaded locos come with Weevil's engine files.
Anyways, thanks for clearing this up, if I plan to use dynamics on a run, I'll check the config file first!
Just one more question, so, if you have two SD40-2s (equipped with dynamics), and add another two, you will have twice the braking power? This also is modeled in Trainz?

November 22nd, 2006, 12:35 AM
Twice the braking force with 4 compared to 2 loco's ? I haven't tested that but since the tractive effort adds up (and so does the weight of the cars) I expect the same in dynamic braking.

I don't know if there's a limit of how many cars the game-engine can handle as for calculating weight and braking-action, but I suspect so.

The longest heaviest trains I pull are 25 50' tankcars, the train weighing in at around 2300 metric tons and I must say with 2 SD40:s the dynamic braking downhill is limited.

You can ofcourse make your own engine-file (I've done that for some I didn't find accurate.) then if it's considered a blesphemy or not - hey it's your sim your railroad. Remember - in order to protect the original engine/loco - always make a clone to experiment with first.


November 22nd, 2006, 04:16 AM
:cool: With USA railroads, a rule of thumb, is if the speed, downhill, under full dynamic braking exceeds one-half mph, it's time for a brake application.

The amount of application, is related to the weight of the train, the steepness of the grade, etc.

The dynamic brake is still used, however one must bail off the air on the locomotive brakes. Bailing off the engine brakes prevents wheel slide.

Trainz Engine Editor (http://www.stw.se/tee.html), is a tool used to tweak enginespec config.txt files.

A locomotive force calculator (http://www.alkrug.vcn.com/rrfacts/RRForcesCalc.html), is from Al Krug, a locomotive engineer with BNSF.

Years of experience, led Al Krug to post Railroad Facts & Figures (http://www.alkrug.vcn.com/rrfacts/rrfacts.htm), to explain in depth, how engineers handle tonnage, and horsepower, vs tractive effort...

And Ferngren is doing a great job of that too! If you need some of the material explained, please post! I so enjoy learning and sharing, because Knowing, & Sharing...Is The Only Way!

November 22nd, 2006, 09:42 AM
Thanks for those links! They are very neat. Anyways, that clears it up, so thankyou for helping me out.

I usually pull 50-85 car trains loaded and unloaded, and since the routes I run have no grades, I don't really need the dynamics, well, except on Crawford!

November 22nd, 2006, 10:28 AM
backyard: thank You very much for lots of info.....:)

im a long time user of MS Train Simulator, so I know about Dynamic braking (....Cajon Pass grade is my teacher...:)). But in trainz I m not so experienced, because I like to sitting in surveyor.

November 22nd, 2006, 12:33 PM
Thanks backyard for the links - invaluable information. Just for fun I tried out the difference between 2 and 4 loco's in dynamically braking the same train on the same grade and I must say the braking-force will double if not even more.

Unfortunately for me 4 loco's became to much for my old computer, the sound started to fade. Trainz is mucho-craving on hardware, wish I can afford a new one soon - with atleast 2 video-cards...