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N Gauge Model Rail Track Layouts for Double Oval
Just because you only have a small space available—in this case, 2x4 feet—that doesn't mean that you can't enjoy N scale continuous running!
Many manufacturers make tight enough curves that a true double oval is possible in a 2x4 foot layout, with turnouts and on one level. Of course, interest can be added by creating a multi-level layout, but this may be out of reach for beginners.
This article examines the measurements and parts needed for Peco and Atlas N scale set track and fine scale to create a double oval that will fit into less than 1 square yard!
The On-Scene and Off-Scene Areas
This track plan shows a large off-scene area in grey. The reason for the off-scene is to allow extensions such as fiddle yards and rolling stock storage; it's tough to have to rip up scenery to put in extra track, and having a small on-scene area gives the modeler (and the audience) something to concentrate on.
Some limited shunting action is provided, too, although some may prefer to stick with passenger traffic and use the spurs as a branch line with a station.
Other uses might include an N scale yard (scrap metal, maintenance depot, etc.) or just sheds with a station in the foreground.
At each end of the scenic section, on the double tracks, there should also be a pair of bridges or tunnel mouths to provide a scenic break. More advanced modelers might even attempt to cover the off-scene section and use it to create a street or countryside cameo!
Peco Code 80 N Scale 2x4 Double Oval
Peco N-80 set track presents a choice. The ST-17 curves (45 degrees over 11.75 inches) actually will fit into 24 inches, but they don't allow for much of a border. The ST-15 curves offer 45 degrees over 10.37 inches and only take up 23 inches, including a 0.75 inch border.
Subsequently, the example here uses ST-15 and ST-12 curves (R1 and R2 equivalent), giving the following mix of Peco Code 80 pieces:
- 8 x ST-15, 45 degree curves over 10.37 inches
- 8 x ST-12, 45 degree curves over 8.98 inches
- ST-5 and ST-6 turnouts, 22.5 degrees left or right, 3.43 inches long
- Mix of ST-11 (6.85 inches) and ST-1 (3.43 inches) straights
In the case of this example, there are the equivalent of 3 x ST-11 and 1 x ST-1 on each straight section, giving 23.98 inches of straight.
Since the points (turnouts/switches) used are the equivalent length to one ST-1, the runaround loop contains 3 ST-1 and 1 ST-11, plus the turnouts, for the same length.
The overall dimensions are 23 x 47 inches, including the 0.75 inch border.
Peco Fine Scale (Code 55) Double Oval (Impossible)
In Peco fine scale, while there are curves that will fit into the 24 inch restriction, allowing a double oval to be built, it is nearly impossible, using N 55 set track pieces, due to the turnouts available.
The image here shows the closest that it is possible to get, without starting to cut the track to fit.
For those who wish to pursue this can create a 25 x 46 inch double oval with no crossovers or run around loops using the following pieces of Peco Code 55 track:
- 8 x ST-18F and 6 x ST-11F for the outer loop
- 8 x ST15F and 6 x ST-11F for the inner loop
From here, points will still need to be added to include runaround loops, or to allow trains to move from one loop to the other.
Atlas Code 55 N Scale Double Oval
The image shows a simple double oval with two places where trains can cross from the outer to the inner loop (or vice versa). Each crossing point uses two facing points (i.e. two right-hand turnouts or two left-hand.)
The track geometry is such that an Atlas Code 55 N Scale turnout (switch/point) is the same straight length as the #2002 6" piece of track.
Set track used in this double oval:
- 16 x #2010 22.5 degree curve, length 10"
- 16 x #2012 22.5 degree curve, length 11.25"
- 8 x #2002 6" straights
- 2 x turnouts #2052 (left) or #2053 (right)
The mix of turnouts (switches/points) used will depend on how the trains are to run—in the same direction, or in opposite directions. Other turnouts can be used to construct sidings inside the inner loop, to provide fiddle/storage space and operating interest.
The layout is 24 x 48 inches, when a 0.75 inch border is figured in all the way round.
Atlas Code 80 N Scale Double Oval
This double oval in Atlas N-80 set track is very similar to the Code 55 example, set up to provide a short run-around loop using opposing sets of points (i.e. left and right turnouts/switches.)
A single turnout (switch/point) in Code 80 has a 15 degree curve, and a straight that is the equivalent of a #2501 (4.88 inches.)
The following track pieces from the Atlas Code 80 range are used to create the double oval:
- 12 x #2510, 30 degrees each, 9.8 inches long
- 12 x #2520, 30 degrees each, 11.1 inches long
- Turnouts #2750 and #2751 - in this case 2 of each
- 8 x #2501 straight, 4.88 inches long
- 4 x #2509 straights, 2.5 inches long
The four small #2509 straights are there to make up the length to 46 inches, and may not be necessary if the runaround is long enough as-is. The exact dimensions are 24 inches x 46 inches, allowing for a 0.75 inch margin/border.
Atlas Tr2 (True Track) Code 65 2x4 Double Oval
The Atlas Code 65 fine scale, True Track range only has one curve that will fit inside 24 inches, and as such only a single oval is really possible.
However, run-around style loops can be added to provide sidings inside the loop, as per the picture.
To achieve this, the following Atlas N-65 track pieces have been used:
- 16 x #2410 22.5 degree curves
- Turnouts #2431 (right) and #2430 (left)
- 6 x straights #2401, 6 inches and 2 x straights #2404, 2 inches each
These are the only kinds of points available in the range, too, which limits the design still further given the restricted dimensions.
The final layout size is 48 inches long, and 24 inches deep, including a 0.75 inch border.
Bachmann EZ-N 2x4 Double Oval Attempt
The Bachmann N-EZ range of nickel-silver N gauge doesn’t have the appropriate curves to create a double oval. The smallest curve is 11.25 inches long for a 30 degree turn and exactly 24 inches deep.
This wouldn't allow for an inner-outer double loop, and even the single loop wouldn't allow any margin around the 24 x 48 baseboard.
It is, however, very high-quality track, and as such worth finding a little extra space. For example, 6 x 4 feet (72 x 48 inches) gives ample space to be creative, for the more experienced modeler.