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BNSF_EMD
August 20th, 2016, 11:25 AM
Yesterday I created a route with a fairly severe grade (2% ruling). This route has less severe grades than, say, Tehachapi Pass. And, as is the point of the program, I decided to drive some trains over the line.

I began with five of Jointed Rail's Demo Dash-9s, with 60 Hungarian gondolas attached. The grade involves two horseshoe curves within a mile or two, and I had just cleared the first of these when I received a warning that my locomotives' traction motors had "reached short-time," and were shutting down to avoid overload.

This puzzled me. I was under the impression that DC traction locomotives could, under certain circumstances, maintain full throttle for far longer than I had before reaching their short-time rating. But I hadn't been looking at my ammeter, so I figured I had done something wrong and thought little of it.

Then I tried something else: AC traction locomotives. The purpose of AC traction is, primarily, eliminate short-time ratings, so I thought I couldn't fail. That's reasonable, yes?

Nope. Even though I started from higher up the hill, I received a short-time rating notice, my traction motors shut down, and I started to stall--with three AC traction locomotives, at least one of which was of Jointed Rail origin and should, in theory, not be afflicted with this problem.

So how, I ask you, can I get rid of this system? Or, at least, make it actually follow the laws of physics? Is it a problem in the scripts of the locomotives themselves, or is it endemic to the game?

cascaderailroad
August 20th, 2016, 11:30 AM
Try adding 2 more helpers shoving on the rear ... 2% is a pretty steep grade

BNSF_EMD
August 20th, 2016, 11:35 AM
2% is indeed a steep grade--but surely with a horsepower-per-ton ratio of 3 and three AC traction locomotives I should at least make it three miles? And that still doesn't solve the main issue; AC traction locomotives do not have short-time ratings! Why did I receive short-time rating warnings on AC units? It's extremely inaccurate, and very frustrating.

Enzo1
August 21st, 2016, 05:14 AM
2% is indeed a steep grade--but surely with a horsepower-per-ton ratio of 3 and three AC traction locomotives I should at least make it three miles? And that still doesn't solve the main issue; AC traction locomotives do not have short-time ratings! Why did I receive short-time rating warnings on AC units? It's extremely inaccurate, and very frustrating.
You left out a lot of details here. How much exactly did the train weigh?
I'm not sure how inaccurate it really is, it would be hard to say. I assume that you probably operated said unit in the red for too long, and just like any other traction motor would go into burn up mode and shutdown. It would be more interesting to hear from a real engineer or somebody who knows about how it works, input on the topic.

hiyo
August 21st, 2016, 06:14 AM
Try using JR locos with all JR rollingstock. Here's a related thread I started a while ago

http://forums.auran.com/trainz/showthread.php?116714-Numbers-of-locomotives-required-for-mountain-routes