Width of Circle

[Anonymous]

Being newly retired, and finally planning on building my first layout in N scale, how wide will reverse loops at each end of my plan be with 24 radius curves?

[JCasey]

Hi Jerry,
Welcome to the forum. If memory serves correctly, radius is half the diameter of the circle, so 24" radius would make the loop 48" minimum. Don't forget to leave some room for easement.
Good luck, and have fun, John

[NZRMac]

24" R curves will be fabulous in N scale!!

Ken.

[Anonymous]

[#ditto]

Yes, will look great, and you can run long cars and locos.

I think you know well enough that 24" radius means a 48" diameter circle, but where is that measured? According to NMRA it is the centre of the track.

Therefore to the outside of the track would be another 1/2" or so (12mm). But then we need to take into account clearances. See NMRA S7.

As I see it you have 48" plus 2 x 19/32" which gives 48 + 1 3/16 or 49 3/16".

I don't know how your track leads into the circle, but do not forget lead-in or easement.

Does that confuse or clarify?

http://www.nmra.org/standards/

[Anonymous]

Thanks for all your help. It's been a looooooooog time since I was in school !!

[Anonymous]

Me too. A long time out of school that is. Good luck on your retirement. A bit of time for trains! [:D][:p]

Half your luck.

[Anonymous]

It's probably minimal for a 24 inch radius in N, but if you plan to run long passenger cars, the ends will overhang a bit. Not a problem unless you're right up against a wall or something else fixed.

[Modeloldtimer]

If I remenber correctly N scale has a min radius of 9" inches.
Therefore a radius of 24" in N scale is great. Most of us in HO if using a 4X8' base have to a use 18" to 22" min radius. A 48" oval of HO track will not fit on a 4X8' base.

[Anonymous]

Listen there bush9245; if he's not confused I am!!!

The answer to the question is this: twice the radius plus the track gauge. N-Scale has a track gauge of nine millimeters or .35433 inches - call it 3/8ths of an inch.

24 X 2 +.35433 = 48.35433 inches - call it 48 and 3/8ths inches.

By the time you add a healthy four inch clearance on each edge (for scenery and security) your going to need 56.35433 inches - call it 56 and 3/8ths inches.

[BR60103]

QUOTE: Originally posted by rtpoteet
By the time you add a healthy four inch clearance on each edge (for scenery and security) your going to need 56.35433 inches - call it 56 and 3/8ths inches.

Why not call it 56 1/2 inches? Then it will just fit inside a standard gauge railway track. [:D]