Hey folks I’m fairly new to the hobby and I’m in my design phase right now. I’m looking at Modeling a frelanced Modern day layout in N scale. and was curious what should be my minimum radious for my layout? I’m looking at running intermodal trains, passenger trains and large 6 axle locos.
Also another question that has been bugging me, might sound like a newby question well thats because i am a newby. but how do you measure the radious to determin that minimum radious?
Also any online articles that out their that may help me with would be greatlly appreciated or books that you would recomend.
Many model RR booklets (good ones available from MR) give guidelines on track radii, clearance between parallel tracks, etc. Suggest also look at some of the NMRA standards and recommended practices here as they can be enlightening:
You might also look at some of the equipment you desire on manufacturer’s website where they often describe a minimum radius that the item will negodiate.
I’m recently back into HO. Many consider 22" radius a minimum, with 18" ok with some equipment from a tracking standpoint. But how things loook is another matter. Long 85’ passenger cars barely negotiate my 25+" curves, for instance, where 30" is probably a much better plan as a minimum. Articulated steamers may negotiate 22" curves, but not look too realistic. You will note that actual RR mainline curves, scaled down, are pretty big, so it’s about compromise. Consider also what turnouts you will use, which have a radius on the divergent route that the equipment must handle.
If you can, use “broad” curves on your mainline. In HO, I think that’s 30" radius, but many folks in HO can’t do that if their layout width is limited.
The minimum radius ‘rule of thumb’ that Cuyama mentioned is real good. If your minimum radius is equal or greater than 3 times the length of your longest car - You should have no operational issues. Of course, appearance will be another matter! Since you want to run large 6-axle power, and long cars, you should keep your curves no smaller than 18"-21" radius as a minimum of operational reliability.
For example, if your longest car is about 80’(6 actual inches), then your minimum radius should be in the 18" range. Larger is better!
I model in HO - and my minimum radius is 30". 40’ & 50’ cars look real good on these curves. My 85’ passenger cars will reliably run around the curves, but sort of look ‘toy-like’ when viewed from the outside of a 30" radius curve.
My first HO layout had 22" radius curves - OK for 4-axle GP’s and 40’-50’ cars, but I did not run passenger cars!
On my last N scale layout i used 19" minimum radii curves.
the reason bieng is the Bmann Acela would NOT run on any curves smaller than that, otherwise it ran ok it ran best on broad curves.
now for 6 axle locos, My Kato SD70M ran like a champ on the 19s also the SD90 ran pretty good too…
so make your minimum 19, anything less in N is just goofy…
BTW I’d look into using Kato Unitrack. It’s going to be a lot easier to use than doing flextrack and cork roadbed etc. It also allows you to test out track plan ideas before making them permanent. There are a lot of track pieces, bridges, etc. available in their line.
There is also “the good 'ole eye it up trick” based on simply observing your car overhang. If it doesn’t look good, and you have the layout room to make a bigger track radius, then that adjustment is probably in order.
A smaller car overhang means you have literally used a greater radius – And vice-versa. In other words, is it pleasing to your sight?
Modern cars like intermodals are now commonplace, whereas, if you are modeling circa 1950s, the only cars then approaching longer length of today’s freight cars were passenger cars.
I read in Model Railroader that 18" rad curves make modern day rolling stock look great. They’ll run on sharper curves, but the unrealistic overhang makes the cars look bed. In general, the wider the curve, the better.
Actually last time I checked, there are no 18" radii curves in N scale, so you might want to go with 19" curves instead, both Atlas and Bachmann produce 19" curves, not sure if Kato does or not, and either way long freight cars locos and passenger equipment (as i said before) look great on 19’s.
But if you want 18, flex-track might be your option that and flex track when done properly in any scale looks better for Modern era’s due to most Class 1 RR’s use welded rail, and Flex-track typically looks like welded rail.
