Hello engineers! Share your experience, I'm trying to lower a train of 95 wagons from the pass, towards Barstow. There are 4 locomotives in the head, 3 in the tail. I lower it on the dynamic brake - it works on all locomotives, I checked. I'm trying to keep the speed no more than 15 miles per hour. When the train reaches a slope of 3%, the speed increases inexorably, up to 60-70 miles per hour. The dynamics does not hold, when the automatic brakes are activated, and it turns off altogether. I've tried it several times already - what am I doing wrong??
Once your train brakes are up to pressure you need to bail off the loco brake so the dynamics come back
You may need to set the autobrake to 80-90% anyway, but the key thing is to bail off the independent brake each time you change the settings of the auto brake. If you are not doing that, the dynamic brake will not work at all and you really need that. Also, do not forget to turn banking comm on. If you forget, the rear locos will not help to brake.
That's right, the connection with the rear locomotive works for me. I checked through an external camera - the dynamic brake on them is working at full. Next, I activate the automatic brake on the train, while immediately releasing the independent brake. The fact is that the dynamic brake is then restored only on the head locomotives. The tail ones stop slowing down with dynamics.
As a result, I try to lower the train - the automatic brake is applied at 100%, the independent brakes are released, the dynamic brake works as much as possible, on all locomotives, head and tail (checked). Nevertheless, the speed increases, starting from 10 mph, slowly at first, then faster, when over 25 mph the efficiency of the dynamic brake drops, it grows very quickly. The locomotives in the composition are different, both EC44 and SD70. Perhaps this is the reason. I'll try to remove the add-on from SD70.
Do you have sd70aces as the rea rdpu? If yes, so they are broken in terms of restoring dynamics after bailing off independent brake (only solution is to manually (sic) by window baill off independednt brake in the rear leading dpu sd70ace to restore dynam.). Every freight loco in TSW are somehow broken (braking, length counter, EOTD, etc etc, - es44c4 is the least affected though and dynamics should work just fine in this loco)
Do not rely entirely on dynamic brake, you should combine both the automatic brake and the dynamic brake. An example of good practice bringing the train down the hill (at least from my experience & several online source) are: Try to maintain 25-30 mph; Use about 50-75% dynamic brake, do not exceed this number if possible (it's important to not use max dynamic brake since it is our last line of defence if something went wrong, imagine if you're already using max dynamic brake and full application of auto brake but the train still accelerating.); If the speed begin to creeping up again, apply initial reduction/minumum reduction on the auto brake, once you applied the auto brake, actuate your independent brake by holding the independent brake in bail-off position until the BC value reads 0, remember to do this on every reduction you make; Watch your accelerometer & your speedometer, see if any decceleration or acceleration take place; If your train still accelerating, try to make another auto brake reduction, usually 8-10 pound of reduction is enough to hold the train speed; If you sure the train is behave nicely & controlled, now you can regulate/adjust the dynamics as required to maintain 25 mph, Congratulations now you've mastered the beast and bringing it down the steep grade. I found this video is very useful and helpful, some of my advice come from this video:
https://www(.)youtube(.)com/watch?v=XoV7D_r-zLc&t=141s try to use this link. (Delete the brackets that surrounds the dot)
I suspect your problem lies in having SD-70s in the trailing MU; as mentioned above their dynamics are effectively useless, unless you bail them off manually. Tell me, is this a timetable service, or something from Scenario Editor? I can't imagine BNSF actually routes 95-car consists down the old 3% line.
DTG for some reason decided to route most of the Westbound traffic in timetable mode down the 3% grade, for probably "Gameplay" reasons. Though in reality BNSF if the line is available, would route most of their trains down the other 2 tracks. Of the few times I've been to Cajon Pass IRL, the only train I've ever seen on the 3% grade was a late running Southwest Chief.
Chapter "Ascents and descents", task G-HOULAC6-07. As a result, I removed the SD70 locomotive from the simulator and normally lowered the train from the pass. Only from ES44AC alone. The descent took place normally, provided that the speed was maintained, not exceeding 25 miles per hour. Otherwise, the dynamic brake loses its effectiveness and the train begins to accelerate.
After last update sd70ace seems to have improved dynamics as rear dpu, it is still loosing dynam. after applying auto+bailing off indep. but after few sec. dynamics rise/recover back (it takes few seconds so you loose almost half of the lbs on notch 8)
... Or it was like that all time , but no one waited long enough at rear dpu, to observe dynamics recovery... Im not sure.
I had a run today on ACe, actually the DP behaviour is still the same as always (not mirroring our air braking input). The dynamic brake works briefly when an uncommanded/unintended auto brake release at the rear of the train. The Rear BP indicator read a fluctuating value between 78-82 and make the auto braking not effective.
! From my experience about sd70ace as rear DPU behavior: 1) Auto braking is broken (es44c4 is good example of how it should work at least) 2) Dynamic brakes drop after applying autobrakes+bailing off BUT, they recover few second later (still having the autobrakes applied) IRL DPU is able to mimik everything except independent brakes, so Ace's are broken in terms of Automatic brakes - rear DPU locos dont activate BP, their brakes, they behave as usual cars (es44c4 does thought) Conclusion: DTG should make es44c4 braking physic as a common standard for all US freight locos, then we would have some consistency in game experience. For now it is just a huge mechanical/physical mess between us freight dlc's.
I remember reading somewhere that dynamic brakes were broken on some US train a long time ago. Around Marias Pass, I think. Haven't bothered with them since. And I find their behavior, that is, them getting weaker as the speed goes up, to be annoying. Finding a sweet spot is like balancing an upside-down pendulum. Requires constant and frequent correction. So, without Dynamic Brakes, here's my advice on what to do on a steep downhill. This is probably bad IRL practice, but let's put that aside for videogame reasons. As the train gets into the downhill portion, slowly increase the independent brake in such a way that the speed stays more or less constant. When the independent brake is at "Full," carefully increase the automatic brake, similarly maintaining speed. Don't forget that the Brake Pipe (which is what actually stops the train) changes very slowly to match the Equalizing Reservoir (which is what you control), so look at both numbers and at the "Rear" display, and don't overdo it with the autobrake. At any point, if you find that you've applied too much autobrake and the train starts to decelerate too rapidly, release a bit of the independent brake to fix that, then re-apply it first, before going back to increasing the autobrake. When the train is fully on the slope and the speed is stable (or slightly decreasing), you now have the ability to release/apply the independent brake as needed and use it as a relatively responsive acceleration control, since the independent brake doesn't need to be fully released to be re-applied. Obviously, don't put it into "Bail Off" at this stage. The downside to this is that the Independent brake gives limited control, so you have to be pretty on point with the autobrake application. Otherwise you'll just find yourself with a slowly stopping train, and it's not like you can just release the autobrake. You can, of course, correct that by applying some throttle, but that's probably bad IRL practice as well. In case of G-HOULAC6-07, I ended up with 74 PSI in the brake pipe during the first portion of the drive, and then was able to just use the independent brake for the rest of the descent as a means of adjusting braking force, as the slope changed slightly. I probably could've applied a tiny bit more autobrake, as the independent one ended up only moving between 70% and 95% on the 3% gradient, but that only goes to show that the control it gives is enough. Conveniently, as the 3% changed to 2%, and the autobrake had to be released, the speed limit increased. So I released all brakes, allowed the system to recharge a bit (so that I wouldn't run out of autobrake on the next application), and repeated the procedure. I've not driven a heavy freight service on CJP in some time, so you can see me being a bit too cautious at the start.
You don't apply independent brake when running a heavy freight train and certainly don't control your train speed with it. It is very very prohibited action to apply independent brake at main line speed.
There are 2 places in the post where I say that these probably aren't good IRL practices. This was done specifically to try to preempt people jumping down my throat regarding proper train-operating procedures. Oh well.
Jest checked Cajon Pass, Ihad sd70ace as rear lead dpu unit, so it is broken: dynamics vanish after applying autos and dont recover with bailing off independents, only manual bailng off through window (sic) works (remaining dpu es44c4 lost dynamic too, mimiking ace). pity old loco - new route - broken experience... Thats why it is difficult to establish downgrade speed with broken aces in squad. Temporary solution (until DTG fix it ;D): NO sd70ace as rear lead DPU loco.
Sorry for resurrecting this old thread. The recent announcement of the BNSF SD70 being necessary for the new MBTA route got me interested in her. Is this issue still present or was it ever fixed? If it’s still there, are there any good workarounds to get the dynamics working or are trains with the SD70 as an MU/DPU just not feasible to run properly?
do not come up on top of the hill/mountain at full speed make sure you are not above 25/30 mph once the train is above 40mph it is really hard to slow the train down
I attempted several times myself doing downhill runs on cajon pass but always ended up with a runaway and i've tried descending it around 15mph from the summit but the Dynamics on the SD70 do not work whatsoever
You also need to use the train brake, but do not forget to bail off the loco brake when you change the train brake settings. I did not play the SD70 for a while, so I am not sure if it is working properly.
I tested it and dynamics are working as the should. The only thing I can think off, did you put the throttle in idle? If you don't, the dynamics will not work.
