# Math People!



## 05Slowbalt (Dec 19, 2011)

So I am now building my Helix. Well I am dropping 5" in 182". Whats my grade %? Ready go!

Thanks.


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## golfermd (Apr 19, 2013)

2.7%. Very steep.

Dan


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## Davidfd85 (Jul 4, 2011)

What is the diameter of the helix? I'm not 100% sure but me thinks that might make a difference.


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## 05Slowbalt (Dec 19, 2011)

Thanks golfermd


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## 05Slowbalt (Dec 19, 2011)

Davidfd85 the helix is huge. The track is 6' from center to center then center to center. So a half circle is 36". It is not overly large but the turn is not tight. There are only to lines on the helix so the inside will be a little smaller. I am hoping it will work. I could make it drop less inchs if needed but what I have it at right now is what I would prefer. Do you think with the turn and % grade it will be to much?


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## Brakeman Jake (Mar 8, 2009)

The 2.7% is indeed quite steep though manageable in a straight line with good tractive power.Add a curve to this and the real percentage equivalent climbs real fast.I can't come up with a precise number but I'd say you'll end up with something like 4 to 5% climb.Be sure you have good horses.....


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## cv_acr (Oct 28, 2011)

05Slowbalt said:


> So I am now building my Helix. Well I am dropping 5" in 182". Whats my grade %? Ready go!
> 
> Thanks.


(Rise / Run) X 100%.

Pretty easy.


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## gunrunnerjohn (Nov 10, 2010)

Davidfd85 said:


> What is the diameter of the helix? I'm not 100% sure but me thinks that might make a difference.


Actually, he gives you that information in an indirect way. If 182" of track in a circle is the circumference, the diameter is 58", or close to five feet.


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## Carl (Feb 19, 2012)

I sure hope you can work out a 2% slope. After all the time design the thing and then to build it and then find the engines have difficult time on the HELIX.......

This link seems to address the HELIX and it maybe of benefit to you:

http://modeltrains.about.com/od/layoutconstruction/ss/Building-A-Helix-For-Your-Model-Railroad.htm


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## golfermd (Apr 19, 2013)

Carl said:


> I sure hope you can work out a 2% slope. After all the time design the thing and then to build it and then find the engines have difficult time on the HELIX.......


Even the Union Pacific Big Boys struggled going up grades that were were just a tad over 2% coming out of Cheyenne.

Dan


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## 05Slowbalt (Dec 19, 2011)

I think I am just going to start my Helix over and readjust how I am running my lines. If I take two of the main lines on the ground level and make it into one line then that gives me a little play. The reason I was trying to drop 5" in 182" was so the upper level of the layout would be flush where the ground level is. Once there together they then drop to the lower level under the table where there is staging.


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