# Question about minimum radius



## CliffyJ (Apr 29, 2009)

I'm still in the planning stages on my short line (and short engine) model railroad, and have been working with a minimum radius of 5'. 
I've heard that 5' is a good minimum, so I've stuck with it -- even on hidden trackage.

Question: am I wasting space on hidden curves? And is this mainly an aesthics thing? Because if it is, I'd love to reduce to 4' min radius on hidden tracks (e.g., a helix and a couple loop-back tunnels). Or are there other issues at play? FYI, the biggest engines I'll ever use here are 4-6-0's.

Thanks for any insights anyone might give,
Cliff


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## Gary Armitstead (Jan 2, 2008)

My old outdoor layout was four-foot radius minimum. All LGB 1600 curves and flex. That's OK for an LGB Mogul and short narrow gauge cars and Bachmann passenger cars. It looks good and most equipment works on it OK. It doesn't matter if the track is hidden or not. You need the larger radius' for the equipment you're running. Five foot radius is the better choice. On my new railroad, which is 1/20.3 narrow gauge, my minimum radis is ninety (90) inches. Looks much better. Now I have 300 feet of LGB brass 332 in storage including 1600 turnouts!


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## Nohandles (Jan 2, 2009)

My old layout was all 5 foot radius accept for rail years. When I got the new layout going I decided after running the 1:20.3 K-27 and the Ariso Mallets that 10 foot radius would be a lot better. I had 4 boxes of 10 radius to use and for the rest I re radiused the 10 diameter stuff. It looks more real on the 10 foot radius curves.
I would go as big as you can afford.


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## Greg Elmassian (Jan 3, 2008)

Actually hidden curves is where you want MORE reliability, and wider radius, you don't want things going wrong when you cannot see them. I cannot tell you the number of people who started with smaller curves and WISH they had gone 10' diameter minimum. 

Regards, Greg


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## eheading (Jan 5, 2008)

I have to agree with others that the bigger the radius the better. I also certainly agree with Greg that for hidden track you want the best reliability you can get.

However, I have several areas on my railroad where I have 4' radii (8' diameter) and I have never had a problem with my Dash 9 running on the smaller radii. Suspect a Mallet or a Big Boy would have trouble with that sized radius, but since you are running smaller engines, I wouldn't think you would have any problem at all.

Ed


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## jmill24 (Jan 11, 2008)

Ed, I would run a Mallet on your 4 foot radius curves. I'll show you in September...................Jim


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## CliffyJ (Apr 29, 2009)

Thanks all for your thoughts. Sounds like it wouldn't be a great idea to run hidden trackage with 4'R. Bottom line is that sticking to the 5'R will eat a little but into the planned patio area... not a big deal for me, but it might be for my (very supportive) wife. I just wanted to make sure that I wasn't taking up too much room for something one wouldn't see, without any point, before asking permission for yet *more* real estate from She Who Must Be Obeyed.









Just wish it were a more exact science, but there ya go.

Cliff


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## Totalwrecker (Feb 26, 2009)

Hey Cliff, 
My 4-4-0 wants to climb my half circle of 4' radius track, while she sails through the 5' radius track with no problems. At 1/3 speed (15mph) she behaves much better. 
That's ok because my 4'r is an inside spur and is level. 
The helix should be as big as you can. 

Regards, 
John


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## eheading (Jan 5, 2008)

You're on, Jim!!

Ed


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