If HOn30 runs on 9 mm track

you can Google for OO9 which is the UK version, from what I can see in a quick browse radii start at 6" (!)

edit: http://hon2jeff.blogspot.nl/

cheers, Leo

HOn30 = N scale

Track wise HOn30 is N scale track width. So any thing that N scale can run on so can HOn30.

I've been playing around with my lime stone quarry part of the layout and plan on using HOn30.

Bernd

Industrial or main line

Industrial lines can have much tighter radius than Mainelines.  I'll be modeling a small piece of the Maine 2 footers, with 8 wheel cars and 2-6-2  and 2-4-4 locomotives, but if you're using really short, industrial trains, you should be able to go really tight.  My sketch has radii no less than 10"

Absolute minimum

Does anybody know what an N scale 0-4-0 can manage?  I would guess it would be in the 4" radius range, or less.  I've seen small HO mechanisms run on curves as small as 6", so surely an N scale mech. would do better than that!

Lot's of info here:

http://www.carendt.com/

cheers, Leo

Track radius is a factor of car length

Track radius is a factor of car length and also what you're trying to achieve ... namely:

- Smallest radius things will run on reliably regardless how toylike it looks
- Smallest radius where things look halfway decent
- Smallest radius where things will couple reliably (important for yards)

All these points are covered in MRH issue 1's Curve Radius guidelines article. These guidelines are scale independent, since they're derived from car length.

Absolute minimum

Ken, I took an Atlas Davenport 0-6-0, and removed the middle drives.  I used this on a 12" diameter over-under folded loop diorama.  I had to get the radius at 4", and it worked fine.  It does, however, look a little odd as even the short engine overhangs the track a lot.  That said, it works and runs fine. I also printed single truck cars to pull behind it, and printed a shell for it.

Thanks!

Since what I'm thinking of would resemble the little industrial lines, or possibly even traction, tight curves and the associated overhang wouldn't bother me.  In fact, I'm considering something inspired by the likes of Malcom Furlow, though possibly with an eastern theme.  Whatever it might be, it would be fun and cute rather than strictly prototypical.

Kent, that's exactly the sort of data I was hoping to find.  Did you get the feeling that 4" was the minimum the Davenport could handle, or do you think it could have gone even tighter?

Dear Ken, For Maine and other

See also......

....  http://www.hon30.org/

by Frary & Hayden, the very ones that started this craze...

Also: http://hon30.com/LC/index.html

There's a yahoo group also:

http://groups.yahoo.com/group/HOn30/

Google " Carrabasset and Dead River "

Jose.

Yosemite Short Line

I use a 7 inch radius curve which works with a Joe Works Shay and home-built flat cars.  The 1:1 Yosemite Short Line had curves that would scale out to 12 inch radius.

Ideas are forming

On a related note, what sort of grads can most small HOn30 equipment handle, and how much vertical separation would you typically need between overlapping tracks?  I usually shoot for 4" in HO, but I'm sure it could be less in HOn30.

Min radius

What I have in mind

Here's roughly the plan I have in mind (I do now, anyway - made it up this morning):

HOn30, 1'x2', 4" minimum radius.

That's a standard gauge 30' hopper parked underneath, by the way.  The general idea is to have a mine (maybe coal?) on the right side, and unload into S.G. cars on the left.  The spur in the lower center would be an engine house.  I'm even thinking of trying to arrange a platform and crane on the longest dump track, so that equipment can be brought up to the mine.  I could even squeeze in a couple tiny passenger stations along the bottom of the plan, to bring the miners up and back home, especially if I shift the track up about another inch.

Equipment would be VERY tiny, obviously.  All 4 wheel cars and 0-4-0 locomotives, though perhaps a diesel might sneak in, or even a small Shay if I could make it run on the curves.  The layout could be operated point to point by not entering the tunnels (they caved in years ago, though there's just enough room to switch the unloading tracks inside tunnel #2), with random cars being loaded and requested to require plenty of switching.  With 2" between the levels and 28" run between the points where the tracks cross, that's a 1 in 14 grade, or a little over 7%.  That ought to test a little tea kettle's mettle!

WOW 1 in 14 on a curve !

and I thought I was stretching it at 1 in 20   Did you make a test run / setup ?

cheers, Leo

Test? What's that?

Now why would I do anything silly like that?

I haven't built a thing yet.  I'm just daydreaming, sitting in the hotel waiting for my train back home.  If I actually get inspired to tackle something like this, I'll pick up a little N scale model and see what abuse it can handle.  It might be fun to limit the train length to 2-3 cars on that grade!

Just for fun, I drew some structures and added some rolling stock:

It might be neat to make this part of a Free-Mo module, perhaps with the main line tunneling beneath the layout.  Then I could put a station on the main line and build stairs up to the little tram station above, and of course the loading track would be a spur off the main.  I'll bet it would get a lot of attention at shows!

made by a 14 year old girl:

http://www.nproject.org/nl/minidiorama/chantal-%E2%80%93-alles-draait-om-treinen.html

Height?

While we're on the subject of absurdly tight restrictions, what's a reasonable maximum height for HOn30 rolling stock?  At a first guess, I'd say 10' above the rail, but I'd love to hear what some of the available or common HOn30 models measure.

More than 10 feet, I think

I seem to recall some of the Maine 2 footers are a wee bit over ten feet tall, as near as I could tell by looking at them.  Your line wouldn't need them that tall, though.

...

Max height would all be based on the height of your tallest piece of motive stock and a person sitting on it...just be sure to include tattletales before and after ever bridge!!

Minimum radius is more than the tightest curve for a loco

On my first layout I had one industrial spur that had a 15 inch radius coming off of the diverging route of an Atlas snap switch.  I had no intention of working that spur with anything bigger than a Gp9, or sw1200.  I did try out an Athearn SDP 40 for fun.  The loco would make the curve, but if a car was coupled to the loco, the extreme over hang would cause the car to lift up on one side of the trucks with the other sides in the air.  As it came out of the curve, the car would drop back on the tracks.  This was an Sd40 coupled to a 40 foot boxcar in ho scale.

103 mm--just over 4"

Tomix makes n-gauge power units that can rn on 103 mm track  http://www.ebay.com/itm/Powered-Motorized-Chassis-Tomix-Tomytec-TM-TR01-N-scale-/200890639167?pt=Model_RR_Trains&hash=item2ec603e33f

and also makes 103 mm track.  That's extremely tight-scales to just 29 feet.  That would work for some critters in industrial use--but WOW is it tight--streetcar-type curves.