Looking for some grade profile information

[dtrainBNSF1]

Hello all!

I'm in the middle of testing the revisions for the NKP mod on Horseshoe Curve. I've adjusted the weight, power, boiler, effectivity and various .csv files like I did with the Big Boy and refined the top speed in speed tests on TestTrak. Now it's on to testing for haulage capacity. I'm trying to replicate a feat by NKP 759 on Horseshoe Curve from several years ago: lift a 1150-ton train from Altoona to Gallitzin unassisted. So far I've made it around the Curve just fine, although very slow (which is expected after reading the account from the crew). The problem is actually just over a mile from Gallitzin station outside the tunnels. The line goes from 1.8% to a steep 2.3%. The loco naturally stalls out and I can go no further .

An increase from 1.8% to 2.3% in such a short distance makes me wonder however. Can anyone confirm if the grade profile for Horseshoe Curve is correct? Historically this should be possible but for whatever reason I can't make it happen.

[Bananarama]

http://www.multimodalways.org/archives/ ... harts.html

[dtrainBNSF1]

Okay so I'm looking at the 1983 report for the Allegheny A division. If I'm interpreting this correctly then between "Benny" and "SF" (which is aligned with "Allegheny" which I assume is the tunnel) there's supposed to be a 2.27% grade. Then-RSC did make this section slightly too steep but I get the feeling that dropping the grade .03% would not make that much of a difference.
Well, back to the drawing board then. I'll have to double-check my math.

[dtrainBNSF1]

Well I'm beat.

I finally got a train of approximately 961t. through the Gallitzin tunnels last night before bed but no matter what I do I just can't seem to get 1150t. up through the tunnels like 759 did. So far I've just made adjustments to the .csv file for t.e. vs cutoff. The speed vs cutoff file is just "1" all across the board since in essence the t.e. vs cutoff file performs that function anyway (I wouldn't have been able to get out of Altoona if the value was anything less than "1" - found that out on my first mod)

It seems that the only way to replicate the feat would be to take 15 G-TraX lightweights through the tunnel. I can't do much else - tractive effort is 64135lbf which translates to 64.135 in the simulation file. Increasing this value would be "cheating".

Of course that's figuring with 245psi...the 759 has a maximum working psi in real life of 245 psi but it's also true that it can sustain 250psi with all pops open if you try hard enough (from a crew member here: http://ogrforum.ogaugerr.com/topic/765- ... shoe-curve). I've already made adjustments to the psi in the loco and sim files based on what I found in this link. Perhaps those extra 5psi could make a big enough difference in tractive effort and maybe then I could replicate that historic run. Of course what difference could 5psi make?

What do you guys think?

[FourEightFour]

5 p.s.i. would not make that big of a difference in the real world. What is your T.E. vs Cutoff curve?

[dfcfu342]

Don't forget this is more an approximation than real life. Putting in real numbers and then wondering why doesn't work exactly like in real life is a bit daft. I learned that pretty well messing with car physics before learning that you may have to fudge the numbers a little to get it to feel correct and operate correctly in the game as they would in real life.

They never said that 759 flew over the top of the grade. You can probably add 5% more T.E. to get it to crawl over the top of the grade without affecting the rest of the simulation (approximation) too much. Keep at it until you get the outcome you want, you'll be quite pleased with yourself when you get there.

[dtrainBNSF1]

5 p.s.i. would not make that big of a difference in the real world. What is your T.E. vs Cutoff curve?

My t.e. vs cutoff curve starts at .45 at 10% cutoff and then continues lineray to 1.0 at 75% cutoff.