Hi; I'm having a problem with some "enginespecs" of as many locomotives, in particular those of the SD70M/MAC, SD9043MAC, C40-8/W and occasionally also of the SD70Ace: the problem is that using them with heavy trains on lines with very demanding climbs (such as the Donner Pass of Jango) they tend to slip too frequently once they reach 20-15mph, which did not happen with the old engines with kuid :1.
Can you suggest a solution? Should I delete the new enginespecs and go back to the old ones?
Hi; I'm having a problem with some "enginespecs" of as many locomotives, in particular those of the SD70M/MAC, SD9043MAC, C40-8/W and occasionally also of the SD70Ace: the problem is that using them with heavy trains on lines with very demanding climbs (such as the Donner Pass of Jango) they tend to slip too frequently once they reach 20-15mph, which did not happen with the old engines with kuid :1.
Can you suggest a solution? Should I delete the new enginespecs and go back to the old ones?
There is no need to edit config.txt files to update or change your engine specs.
In the session editor, CTRL+right-click on the locomotive to open the properties panel.
Click on enable editing.
You will see the engine specs used and you can choose another.
In real life, Donner Pass is extremely steep and requires multiple diesels to pull the long freights over the Continental Divide.
Nah i have to disagree, he is right here. Tractive effort is just weird in trainz, has nothing to do with what spec you use or how many engines. No matter what, ~ 150k lbf seems to be the practical maximum the sim allows to be applied to the rails on a 6 axle engine.
I tried changing and editing that a few times, especially for SD70ACEs that are used on 0.6/0.7 HPT (Horespower per ton) 20.000t coal drags that DO creep up hills like that at 10-15mph. In trainz, once you get low speed enough to get over that ~ 150klbf limit in N8 or N7 (About 12mph) - the wheels immediately slip and Tractive effort reduces to about 33k lbf instantly. You then have to reduce 3-5 Notches (not just one!) to stop them from slipping, then increase back to N6 below 150k lbf to keep going at all. Else you come to a stop pretty quickly, cause what is ~ 33k lbf on a steep incline?
Completely ridiculous from real world experience. Not even in rain does TE reduce THAT much, yes the wheels will occasionally slip and overspeed, but a.) can that be remedied by applying a bit of independent brake to arrest them, and b.) does Sand have an immediate effect to stop it or at least increase your TE back up to a reasonable amount.
Which it doesn't in trainz, like at all!
You will still have to reduce your power to near 0 and then increase it up again to stop the slip, even with Sanders active. I've been driving real freight trains half my life at this point, and this is just completely wrong - and sure enough will stall your heavy train on a grade, even if your HPT is more than enough and it never would in real life. Maybe if some TM Ground relays trip, but not due to slip or tractive effort in itself
I have to say however, this doesn't seem to be a JR problem, and i've always had problems like that in trainz with any heavy train & in any version from TS12. It's a hard coded, N3V game engine/physics related issue IMO
Oh and lets also not forget the ear splitting and extremely annoying wheel slip sound straight out of idk, UTC? That is still used
Guys, everything is fine with physics in Trainz. It's just that those who write traction do not want/cannot thoroughly understand the issue. And this issue is not as simple as it may seem at first glance. Or they are not interested in it. And if all the components of the traction/resistance process are set correctly, everything will go as per books and graphs. And the more accurately all the components are set, the closer to the desired result will be. And not only will it be, but it has been going as it should for a long time.
In summary, Trainz engine physics is crap since at least TS12.
You could try modifying your own using the Test Track if that's still available. I can't remember if it's still part of TRS19 and the TRS22 products. The last time I saw it was in T:ANE and it was still unfinished.
Interesting expression... true, meaningless, without specifying the conditions under which such a dependence can be observed. Is such a ratio valid for an ascent, descent or on a flat surface? And so it turns out that this locomotive always and everywhere carries a ton of cargo, using 0.65 hp. flusi737, can you comment ?
Comment on what? It's a unit used by US railroads - not by us in germany, we use kn (metric k-lbf) - to decide how much power a train needs to have for a given grade. I agree it is rather stupid, as it doesn't really correlate to the tractive effort and possible adhesion in different environments, but eh it's what they use and give us.
A "20k" coal / bulk train, with lets say 3x SD70MAC has a HPT of 0,645 - 4,300HP x3 / 20.000t gross weight. The grade this (better 2-3 of them are ACEs or ES44ACs) can "make" is 0.80 % up in this case, at about 12-15mph in N8 in the real world. That is, with AC Units - the HPT for DC Units needs to be higher as they are not as efficient and do not produce the same TE output as AC engines (one of the flaws of the HPT System, as the HP is the same, the TE is not but it doesn't show that, you have to know it)
Nah i have to disagree, he is right here. Tractive effort is just weird in trainz, has nothing to do with what spec you use or how many engines. No matter what, ~ 150k lbf seems to be the practical maximum the sim allows to be applied to the rails on a 6 axle engine.
I tried changing and editing that a few times, especially for SD70ACEs that are used on 0.6/0.7 HPT (Horespower per ton) 20.000t coal drags that DO creep up hills like that at 10-15mph. In trainz, once you get low speed enough to get over that ~ 150klbf limit in N8 or N7 (About 12mph) - the wheels immediately slip and Tractive effort reduces to about 33k lbf instantly. You then have to reduce 3-5 Notches (not just one!) to stop them from slipping, then increase back to N6 below 150k lbf to keep going at all. Else you come to a stop pretty quickly, cause what is ~ 33k lbf on a steep incline?
Completely ridiculous from real world experience. Not even in rain does TE reduce THAT much, yes the wheels will occasionally slip and overspeed, but a.) can that be remedied by applying a bit of independent brake to arrest them, and b.) does Sand have an immediate effect to stop it or at least increase your TE back up to a reasonable amount.
Which it doesn't in trainz, like at all!
You will still have to reduce your power to near 0 and then increase it up again to stop the slip, even with Sanders active. I've been driving real freight trains half my life at this point, and this is just completely wrong - and sure enough will stall your heavy train on a grade, even if your HPT is more than enough and it never would in real life. Maybe if some TM Ground relays trip, but not due to slip or tractive effort in itself
I have to say however, this doesn't seem to be a JR problem, and i've always had problems like that in trainz with any heavy train & in any version from TS12. It's a hard coded, N3V game engine/physics related issue IMO
Oh and lets also not forget the ear splitting and extremely annoying wheel slip sound straight out of idk, UTC? That is still used
Those are modern units with electronics (not solid state like the old pre 1970's units) so I'm going to rule out the series/parallel transition... or am I giving our content creators a bit much credit for realism. For those of you who don't know, the motors in diesel-electric (and I assume regular electric) locomotives have the traction circuitry changed back and forth between series and parallel to apply the correct torque and rpm so as to not over heat the motors. That "transition" affects the output and can change the tractive effort (particularly on 40+ year old worn out locomotives).
My guess is there is a limit in the code somewhere, I haven't personally run into it as I run primarily steam (although I will maybe see about a double header with a helper in the old N&W style with 100+ hoppers [maniacal cackling]).
I agree it is rather stupid, as it doesn't really correlate to the tractive effort and possible adhesion in different environments, but eh it's what they use and give us.
A "20k" coal / bulk train, with lets say 3x SD70MAC has a HPT of 0,645 - 4,300HP x3 / 20.000t gross weight. The grade this (better 2-3 of them are ACEs or ES44ACs) can "make" is 0.80 % up in this case, at about 12-15mph in N8 in the real world.
In this example, the questionable speed is the assumed speed... it's pretty high. At lower speeds, yes, maybe in the 10 mph range.
In the meantime, what can we have in practice in trainz. At the moment there is only trainz TS12 3.7 build 61388.
The initial data on SD70ACE that could be found, as they differ in different sources :
- EMD 12-1010J Tier-4, 4400, 45000, and sometimes 4600 hp
STE 200000 lb, CTE 175000 lb, DB 105000 lb
Weight 420,000 - 432,000 lbs. As for the continuous mode speed, the situation is generally deplorable - there were literally a few mentions, and all of them were different, from 14 to 14.9 km/h.
I decided to take the middle option for testing, T3.
N8
A 2.5% slope of 12 km was built, a 20,000-ton train was assembled, 168 cars weighing 119 tons each, 8 locomotives, each weighing 196 tons. Without any additional settings, purely by default, such a train could move on this climb at throttle position 8 only with sand constantly on, at a speed of 15 km / h, or 9 miles per hour. At the very limit of slippage. If this were not a straight path, the train would not have pulled through. At throttle position 7 there was no slippage, but the speed was lower.
What else can be done to increase the slippage limit with such a locomotive weight?
1. In the locomotive config, write the max-tractive-effort tag, indicating the required traction force. And with sand it will be just beautiful.
2. Use the "Vehicle physics" rule in the session, where you can set the slip limit, traction drop, and sand efficiency. At least in TC12 there is such a rule. It seems like you can customize it for a particular locomotive, but I haven’t tried it.
3. Script.
I added the max-tractive-effort 800 000 tag to the locomotive, and the train began to behave quite confidently on the 8th throttle position on the climb, without fear of slipping.
Total.
By default, with such settings, training allows to realize 700 - 720 kN of traction force. The manufacturer's declared starting traction forces of 820 - 890 kN are in the area of non-guaranteed adhesion, and therefore, in my opinion, are not required to be realized by the game's calculations. And trainz provides several options for realizing greater traction force, everything depends on the understanding of the developer, or the player himself.
So will it work or not? It will work.. All other questions relate to the settings of specific models.
