# 6 ft diameter curves



## rcb (Jan 3, 2012)

While I have no interest in dropping the cash for a G Big-Boy, will 6ft accommodate practically any "G scale" engine? What's a safe radius? Again, no plans, just curious.


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## jmill24 (Jan 11, 2008)

MTH Bigboy - 8 ft diameter
USAT Bigboy - 16 ft diameter
other bigboys - 20 ft

10 ft will run a large selection of engines. 8 foot would be my absolute min. My out door layout is 12.5 min to 14 average. This has worked out good for me..............Jim


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## chuck n (Jan 2, 2008)

There will be a lot of comments here and you need to remember that " you pay for what you get". I would recommend a minimum of 10' diameter for any layout. The large engines need that much to look decent going around the curve.

My ultimate recommendation is to use the largest diameter that will fit into your space.

What type of trains and engines do you want to run? Big boys, Challengers, and any other high end mallet will require larger diameters. 


I have some USAt streamliners and while they run around my 10' diameter curves, they would look a lot better on bigger diameter curves.

The bottom line is what type of trains do you want to run. Long modern trains and engines will require large curves. Narrow gauge logging and mining railroads can be done on smaller diameter curves.

Chuck


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## Semper Vaporo (Jan 2, 2008)

Be careful here! Remember the difference between DIAMETER and RADIUS! I fear some of these comments have confused the two.

My Aster Mike (2-8-2) is spec'd at 2 Meter RADIUS... i.e.: about 6 and a half ft RADIUS, or 13 ft DIAMETER. Running very slowly, it barely made it around a 5 ft RADIUS (10 ft DIAMETER) curve. With any speed at all it would derail coming out of the curve... the wheel on the inside of the curve on the lead truck would lift completely off the rail in the curve and with speed it would come down outside of the gauge, but when running slowly it might fall back to the rail.


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## jjwtrainman (Mar 11, 2011)

If your running anything short of a pacific in length, you should be fine with most engines using 6 ft diameter curves. But why would you want to do something that tight? I would spend as much money on large radius curves as possible. For me, I can only afford 4ft diameter curves, but I don't need anything larger. So the right diameter curves depends on what I see are three things: What you are running on the tracks, what you find the most appealing, and how much space you have. Obviously though, if you have a 24' wide spot to put a railroad, you don't need 24' diameter curves, 8-12 would work fine.


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## rcb (Jan 3, 2012)

Yep, that was my fault on the title. I MEANT 6ft radius. 

IF we end up doing this, we know about where we want to put it. Later this year we will be putting the deck/sitting area and I am just trying to get an idea of how I might want to set it up. My goal is have the track about chest level when people are seated. This all sits on a hillside, so as curves wrap around, I wanted to think of how I will grade it. 

Thanks for the info though to be certain. sounds like 8-10 ft radius curves would be plenty. 

Ideally I think I would like to run a GP30 (my favorite diesel) maybe an SD40-2 (one of my wife's favorites... our first train ride was behind an SD40-2) to SD90/43s and certainly a steam engine or two. Though it doesn't appear that the MACs are available in plastic, I bet that will change perhaps even by the time we might do this a couple years from now.


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## cape cod Todd (Jan 3, 2008)

Hello RCB 
Do go with the widest diameter you can fit into your area the trains will look and run better. On my RR I have from 5' - 10' diameter curves most are 8'. The diameter being measured all the way across, radius is measured from a center spot to the edge of the curve. Most engines with 4 wheels per truck will make it over the 5' curve but I think you will find trouble when you ask a SD40 to do it. Recently I bought a bachmann 2-6-6-2 and all the wheels are flanged vs say a big hauler that is not. I need to rework several spots on the RR come spring to accomodate this larger engine. I also have a USAT GP38-2 and that will make it around without a problem. If you plan on running long passenger cars you will also need curves of 10' diameter or larger due to them looking ridiculous with the over and under hang. 
Building into your hill will be a challenge due to the grades. You will need to keep your track grades to a minimum of 2% if you want to run long trains. 
good luck


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## rcb (Jan 3, 2012)

So, something like this would be ok? (it's a 5 foot grid) I hope this works.The blue lines are the track. The grid is 5 foot.


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## Totalwrecker (Feb 26, 2009)

Track plan looks fine... 'cept reverse loops can be tricky ... depending on your power source. With track power the loops create a short circuit where the right rail comes around to touch the left. 
Battery power and no worries, DCC and there is a power module that eliminates the short. Conventional track power and you'll need lots of wires and switches to avoid the shorts by reversing polarity in sections of isolated track. That makes it harder to run 2 trains at the same time...for example you might reverse the polarity under one train while throwing switches for the other train exiting a r loop. 
Peraps it's time to investigate your power wants/needs. 

Happy Rails 
John


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## rcb (Jan 3, 2012)

I am set on battery power, but likely AirWire. though I run NCE for my N and the wife's HO, but I really like the stand alone unit for Airwire. Seems to be pretty simple. I like the programmability of DCC to be certain.

Of course this is just a theoretical. We still haven't decided precisely where we are putting the spot at or how long our walking path will be, but just getting an idea. Likely it will feature more organic curves but I do want a bit of track frontage near our sitting area.


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## jjwtrainman (Mar 11, 2011)

If you only want 1 or two trains to operate at a time, which is what most people end up doing anyway, the plan you've got would be fine, except I would still include another passing siding just so that you can be more "flexible" when running trains.








But if you want to run more than a couple trains, it would still be a good idea (at least the way I see it) to have the track plan be a dogbone plan. Then you can add cross overs in several places so you can run multiple trains. After discussing on the forum a while back about running multiple trains on 1 mainline, I feel like the best solution is to have many passing sidings along the route so there is plenty of places to pass a train, go around it, or park one. I love to read about other's railways, so please [email protected] url(http://www.mylargescale.com/Provide...ad.ashx?type=style&file=SyntaxHighlighter.css);@import url(/providers/htmleditorproviders/cehtmleditorprovider/dnngeneral.css);


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## Greg Elmassian (Jan 3, 2008)

15 foot diameter curves are great.. You have a bit of an "S" curve where you end your passing siding and hit the other switch. If you are using #6 or greater switches it will probably be ok 

Put #8's in there, will match your nice large curves better. 

greg


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