# Tight turns



## Smokestack Lightning (Oct 31, 2010)

Sorry if this is a repost guys. I was wondering what the tightest radius turn I can make in HO is.


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## aionta (Apr 9, 2010)

Hello Smokestack!

It depends on how long your engines and cars are.

Longer cars (unless they are articulated ) will require longer turn radiuses.

One of the members on this list makes some beautiful chopped down box cars etc that are very short so they would be able to negotiate some pretty small curves.

Hopefully someone else will have more info for you

Aaron


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## Smokestack Lightning (Oct 31, 2010)

I am running a 4-8-4 steam engine.


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## Smokestack Lightning (Oct 31, 2010)

This is it here


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## tkruger (Jan 18, 2009)

If that is the Bachmann one I think it is the minimum is 18r. I think >22r is recommended. That being said, just because it will run on 18r does not mean that it will go full speed on 18r. For example I have an Athearn DD-40 that will run on 18r turns but I cannot go over 40% throttle or the front truck will derail. On 22r it can go all out all day.


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## T-Man (May 16, 2008)

An engine that size is around 18 to 22 inch radius. Smaller, and you increase the risk of derailment and the length of what you want to pull. Nice unit!:thumbsup:


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## tooter (Feb 26, 2010)

All of my shorty engines and rolling stock all easily negotiate 10 inch radius curves...


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## T-Man (May 16, 2008)

Gee, if you really get bored, you can do that in N.:laugh:


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## Smokestack Lightning (Oct 31, 2010)

tkruger said:


> If that is the Bachmann one I think it is the minimum is 18r. I think >22r is recommended. That being said, just because it will run on 18r does not mean that it will go full speed on 18r. For example I have an Athearn DD-40 that will run on 18r turns but I cannot go over 40% throttle or the front truck will derail. On 22r it can go all out all day.


So 22" I'm assuming is for 1x90 degree bend. So for a 180 I'm looking at 44"?


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## tjcruiser (Jan 10, 2010)

Yup ... HO track is measured in RADIUS (rather than diameter), reference to the outside rail. So 44" diameter, measure at outer rail.

TJ


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## Smokestack Lightning (Oct 31, 2010)

Thanks guys. That's what I needed to Know:thumbsup:


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## tooter (Feb 26, 2010)

T-Man said:


> Gee, if you really get bored, you can do that in N.:laugh:


It's actually narrow gauge... 

...except the rails are farther apart.


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## derfberger (Jul 23, 2010)

the engine might be rated at 18 R and run fine but I've found that it will flip off cars, especially if the couplers have a stiff spring.

I had a 12 wheel diesel that made it around 18s but couldn't pull anything for very long before a derail. sold it for the same model in 8 wheel


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## tkruger (Jan 18, 2009)

Smokestack Lightning said:


> So 22" I'm assuming is for 1x90 degree bend. So for a 180 I'm looking at 44"?


When you measure the track placement on you layout do not only measure the diameter or he turns, remember to account for the overhang of the cars and locos. Some locos have noses that stick out over the outer rail while their mid section is way ove the inner (my DD-40 on 18 r is an example of this.) If anything is to close to the side of the track it will get hit. This is also true with the rolling stock. The distance between parallel tracks needs to be greater in turns than in straights.


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## Smokestack Lightning (Oct 31, 2010)

tkruger said:


> When you measure the track placement on you layout do not only measure the diameter or he turns, remember to account for the overhang of the cars and locos. Some locos have noses that stick out over the outer rail while their mid section is way ove the inner (my DD-40 on 18 r is an example of this.) If anything is to close to the side of the track it will get hit. This is also true with the rolling stock. The distance between parallel tracks needs to be greater in turns than in straights.


Nice tip:thumbsup: Is there a standard distance between parallel tracks?


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## tkruger (Jan 18, 2009)

Smokestack Lightning said:


> Nice tip:thumbsup: Is there a standard distance between parallel tracks?


I do not know what the standard is. I took the two largest items I had and ran them by each other in the worst possible situations. Then added a half inch. The additional space was for the occasional derailment, do not want to derail and hit an oncoming train.


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## derfberger (Jul 23, 2010)

2 inches center to center. i have kept mine to a minimum of 20 inches R and still i don't run the 12 wheel passenger cars.

With 18 in it helps to have a transition


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## mr_x_ite_ment (Jun 22, 2009)

Hey Smokestack...Yea, I would be shooting for the biggest radius you can have. I would certainly try for the 22" radius if you can swing it. Like tkruger said, it may go through an 18" radius, but it may not necessarily be pretty. There is nothing worse than a curve that is too tight for certain loco's. Many loco's have minimum radius recommendations, but in my opinion, ALL TRAINS do better on bigger, broader curves. I would even add on to a 4 X 8 sheet of plywood if I had to in order to get the radius to be what I want. Good luck!

Chad


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## tjcruiser (Jan 10, 2010)

Smokestack Lightning said:


> Nice tip:thumbsup: Is there a standard distance between parallel tracks?


Smokestack,

The NMRA (National Model Railroad Assoc.) has a wide array of published standards ... track layout, clearances, electrical guidelines, etc.

You should check 'em out ... quite helpful for someone setting up a layout:

http://www.nmra.org/standards/sandrp/consist.html

Cheers,

TJ


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## pete m penn (May 16, 2010)

Guys allways use largest radius turns you can for space you have avaible. Short wheelbase engines & cars look real good on big radius turns & you can run the bigger engines &cars with out them looking stupid. Exampel 4 by 8 about as big as you can go is 22 inch radius. If you have a spare room say 9 by 12 . Go around the walls type layout bacman E/Z track gray roadbed has radius at 26&28 inch. Also 33.5 & 35.5 inch. And ofcourse there is allways flex track. Many good books out there atlas & bachman EZ track layouts come to mind first, atlas books are called model railroads YOU can build. And there are others. BTW that 484 you have will take 22 inch radius. Sorry about being long winded Hope that helps..


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## Smokestack Lightning (Oct 31, 2010)

tjcruiser said:


> Smokestack,
> 
> The NMRA (National Model Railroad Assoc.) has a wide array of published standards ... track layout, clearances, electrical guidelines, etc.
> 
> ...


Cool link. Thanks:thumbsup:


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## Smokestack Lightning (Oct 31, 2010)

pete m penn said:


> Guys allways use largest radius turns you can for space you have avaible. Short wheelbase engines & cars look real good on big radius turns & you can run the bigger engines &cars with out them looking stupid. Exampel 4 by 8 about as big as you can go is 22 inch radius. If you have a spare room say 9 by 12 . Go around the walls type layout bacman E/Z track gray roadbed has radius at 26&28 inch. Also 33.5 & 35.5 inch. And ofcourse there is allways flex track. Many good books out there atlas & bachman EZ track layouts come to mind first, atlas books are called model railroads YOU can build. And there are others. BTW that 484 you have will take 22 inch radius. Sorry about being long winded Hope that helps..


I find this stuff all extremely helpful:thumbsup:


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## tooter (Feb 26, 2010)

derfberger said:


> 2 inches center to center. i have kept mine to a minimum of 20 inches R and still i don't run the 12 wheel passenger cars.


I do... 









...as long as they have couplers in the middle. 

Greg


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## derfberger (Jul 23, 2010)

i have one deisel that kept jumping the track.. I thought it was because too tight a radius.

Took it to the local Hobby Shop and they checked the width of the wheels with a gauge.

One set was too narrow.

i bought a gauge today and will be checking everything as i also have a few switches that cause problems


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## MadCS (Nov 1, 2010)

*>Radius = >Reality*

Choo Choo...
Sorry for off topic, but I love those shorties... are they custom or the Walthers "Oscar" units from a while back?

Back to topic, I've operated on a local layout using >= 32" min radius and it tracks beautifully, very realistic.


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## tooter (Feb 26, 2010)

MadCS said:


> Choo Choo...
> Sorry for off topic, but I love those shorties... are they custom or the Walthers "Oscar" units from a while back?


Yes. They were Walthers joke cars.  
The observation car is called "Oscar", and the pullman car is called "Piker". They were first released in 1961 as wooden kits, and in later years a few were offered for sale as plastic RTR.

Greg


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