Minimum radius 14" curve recommendations pls

Discuss park gauge trains and large scale miniature railways having track gauges from 8" to 24" gauge and designed at scales of 2" to the foot or greater - whether modeled for personal use, or purpose built for amusement park operation or private railroading.

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ChipsAhoy
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Minimum radius 14" curve recommendations pls

Post by ChipsAhoy » Mon Jul 26, 2021 7:44 pm

If a person were looking for property to run this, What is the tightest radius curve that an engine like this take, and what would those in the know recommend for the best tight radius one should use and still provide a comfortable ride.... no super, but will incorporate spirals into and out of the curves.
Circa 1950, 14" guage Hurlburt park engine.

Disclaimer, I do not own, nor am I purchasing this engine, but I do know it is for sale. I do not own this photo, it has been lifted from a sales add.
(Glenn, I know that you know why I ask, please do not share that because it may not be true.)
Scotty
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Glenn Brooks
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Re: Minimum radius 14" curve recommendations pls

Post by Glenn Brooks » Tue Jul 27, 2021 1:07 am

Scotty, fine looking loco. The Hurlbut’s were well made equipment, and enjoy a nice reputation. This one looks like it has been cared for over the years. Is this the one at the MLS museum, by chance? If not I’d be curious to know where it is located and more about its operating history.

Iam guessing the 4-4-4 wheel arrangement would likely require a minimum mainline radius of 45-50’. Depends on the length of the wheel base and how the leading and trailing trucks are connected. These Atlantic style engines require a bit more turning radius that the more short coupled 4-4-0’s...

Any damage to the MLS layout out in the floodplain at the park?

Glenn
Moderator - Grand Scale Forum

Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....

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ChipsAhoy
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Re: Minimum radius 14" curve recommendations pls

Post by ChipsAhoy » Tue Jul 27, 2021 7:20 am

I haven't been out to the track since the last rainstorm two days ago, but haven't heard of any flood damage yet.
That loco in the picture is for sale in So. Cal. I just grabbed the photo as a rep of what I was inquiring about. I think the link below will get you there.
50', not as bad as I thought. I dug thru a couple of threads here on one 14" gauge being built, but he hasn't gotten that far along yet. Hoping someone who actually operates one could give a little input.
Scotty
https://www.google.com/url?sa=t&source= ... VcW1IDsYeD

STRR
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Re: Minimum radius 14" curve recommendations pls

Post by STRR » Tue Jul 27, 2021 5:49 pm

OK, Let's see if I can get this to work. You will have to click the link, then open the file to have the calculator work properly. It may or may not work from this post.
Minimum Radius.doc
(44.5 KiB) Downloaded 70 times
I hope this works and helps you out.

Good Luck,
Terry

rkcarguy
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Re: Minimum radius 14" curve recommendations pls

Post by rkcarguy » Wed Aug 04, 2021 6:37 pm

The trend seems to be about 5 times the scale in inches, in feet of minimum radius. Subject to be larger if you want to run larger steamers or 6 axle diesels. If I was building track to suit an existing locomotive, I'd build a test section first and make sure it's going to work ok.

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ChipsAhoy
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Re: Minimum radius 14" curve recommendations pls

Post by ChipsAhoy » Thu Aug 05, 2021 2:02 pm

So if I follow... 14" guage X 5 = 70'.
What we are seeing is some existing curved Track panels and we don't know their radius yet. Knowing your "Rule of Thumb" gives a starting point. If they are all say 35', then there is some dickering to be done. If they are 80' plus, we're in the chips!!!
Thanks for the suggestion, I'll get my tape and go have a look.
Scotty

rkcarguy
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Re: Minimum radius 14" curve recommendations pls

Post by rkcarguy » Fri Aug 06, 2021 12:39 pm

It's somewhere to start at least. Glenn is right though, the way the locomotive is constructed with any axle end play, the way the leading and trailing trucks pivot, will all define how tight a radius it can handle. Sometimes you can get everything to work only to find out it will lift a wheel and jump the tracks as soon as you hit a rail joint on a curve.
Another thing to keep in mind, when track transitions from a curve in one direction to another with minimum radius, there needs to be a straight piece in between at least as long as your longest locomotive/rolling stock or the couplers will bind up and actually lift the lighter piece off the track.

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