I have been an ho scale modeler for about the past 5 years and have made all the mistakes one can make. After 4 layouts and countless modifications, I have come to the realization to run the modern locomotives, autoracks, passenger trains, etc. that I like and based upon my space (9.5x15) I must go n scale.
With that said, I am wanting to construct a u-shaped single main line with passing sidings and with vision blocks spliting the layout into 4 scenes. I plan to use kato uni track and my question is what is the proper radius to run the above mentioned equipment? I know the 28 1/4 radius made by kato would be best, but I simply am not sure if I have the room to make the “loop” at the top end of the layout and still be able to walk between the two islands only having the 9.5 foot width discussed above. Also, if I have a passing siding on the “loop” and am going to run a double track at that point, which uni track radius work well together for that?
“but I simply am not sure if I have the room to make the “loop” at the top end of the layout and still be able to walk between the two islands only having the 9.5 foot width discussed above.”
You need to get some paper out and sketch up your room and try different shapes for your main line route.
9.5 feet wide - 2 foot isle leaves 7.5 feet. 7.5 /2 = 3.75 ft per side. 3.75 x 12 = 45inches. 45 inches - 4inches for scenery= 41inche diameter loop. divede that by 2 and 20.5inch radius is the max that will fit. however if you offset the loops you can go much larger. Or if you make the isle wider you need to go smaller, Etc. Etc.
Kato makes unitrack radius for your equipment. Use 15, 19, or 28.
15 has overhang when using Auto Racks, Superliners.
I use Kato track, I’m happy with it. But I’m going to use flex track when making curves. I would like a 19-22 inch so I don’t want to see the overhang, and long switches.
Would the superelevated dual track curves serve the purpose as well? If so, I know they offer a maximum radius peice in the 18 7/8" - 17 5/8" range; would that work?
28 1/4" radius in N scale is equivalent to about 52" radius in HO. That is very, very broad and certainly not needed for N scale to run well or look good.
As others have noted, a sketch of your space would help folks help you. Can you walk all the way around the 9.5’ X 15’ space? Or are one or more sides against walls?
Unitrack may not offer exactly the radii that you would like. The 19" radius equates to about 35" in HO, but there is no complementary radius for an inner curve on double-track. I believe that the next smaller radius is 15".
One often-used combination for double-track curves with Unitrack is 15" outside with 13 3/4" inside. But that smaller radius equates to about 25 1/4" in HO. Virtually any equipment made in N scale will easily run on that curve, but it might not look the way you would prefer.
For modern-era modelers, KATO makes double-track superelevated (banked) curves with concrete ties. One of those is 15"-16 3/8", equivalent to about 27 1/2" - 30" in HO. The only (modest) downside to this is that you need KATO’s easement sections to enter and leave the curves – and you might want to use the concrete-tie straights as well, which are somewhat limited in sizes.
Flex track (or Atlas Code 55 sectional track) would give you more flexibility.
Yes, forgot about that one. It equates to about 34 1/2" - 32 3/8" in HO. Again, these are superelevated with concrete ties and would require the easement sections to transition back to non-banked track for turnouts and straights.
With the super elevated track, how do the easements work; are they needed on both ends of the curve to get back down to level track? Also, is the “gap” between the tracks consistant upon transitioning back to single track or siding tracks or does one have to use “double track” all the way around the layout?
"Please note that all of these Concrete Tie Double Track pieces are 100% compatible with our regular double and single track Unitrack pieces and bridges and can be added into your existing Unitrack layouts!"
**“**in modern railroads, and before now they were complicated and finicky to replicate at model railroad scale level, but no longer! Kato UNITRACK makes it simple with modular easement and superelevated curves, available with modern pre-cast concrete ties”
Suggest you get track planning program that includes Kato track libraries to see what you can do. There are very good free programs available. I like XTrackCad lot of people really like SCARM.
One of the great things about Kato Unitrak is that the pieces are mathematically exact and completely interchangeable. Everything is based on degrees of arc. You do not need to make a complete curve entirely from the same radius pieces. For instance, you can start at the straight tangent using a 28.25" curve for 15 degrees, then attach a 19" radius piece for 30 degrees, then a 15" radius for 30 degrees, then a 13.75" radius piece, and so forth. The result is a perfectly smooth curve of increasingly tighter radius. Using the larger radius pieces at the starting and ending tangents make perfect (kinda perfect) transition easements. The other great thing about Kato is that if you have trouble with the math you can lay out the pieces and snap together to see what’s what. Good luck.