Track Work Standards

Mainline Specifications

Track code

Both mainlines are required to use Flex or sectional Atlas, Peco, Shinohara, or Micro Engineering track, either (nominal) code 80, 70 or 55 rail. All of which are available through your local hobby dealer. All have been proven to work reliably in the past. Neither of the two mainlines shall be hand laid track, thus reducing the chance of variation in the gauge and assuring more reliable operation for everyone in a group setup.

If you wish to use code 55 flex track, you will need to use a small stretch of Atlas sectional track approximately 1" to 2" in length at the ends of each mainline. Don't use a piece of flex track for this as the rails will be loose. Sectional track will keep the rails held securely in place and in gauge even if it is only 1" to 2" long, 2" being recommended. This short piece of Atlas track is needed because code 55 track is thinner overall and won't join properly with the connector tracks which are Atlas 5" straight sectional track (code 80). The use of this section will allow the joiner track between modules to mate with track that has the exact same profile. By using cardboard shims to gradually raise the code 55 track, the rail heads can be made flush with that of the Atlas section at the ends of each mainline. Also, Micro Engineering and Atlas will not join directly with a rail joiner without a noticeable mismatch in the elevation of the top of the railhead. This is separate from, but in addition to, the tie thickness difference. Also refer to the "Tips and Techniques" page  for joining code 55 to code 80 rails

Mainline Placement

Position of the tracks is as follows: Mainline #1 is the main farther from the center of the bench work and Mainline #2 is the main closer to the center of the bench work. To position the mains at each end you first find the center of the 2 foot wide module (if the module is built to the minimum 2 foot width) and measure out both directions 8 1/2" to the center line of main two and 10" out to the center of main one. This should leave 2" from the center of main one to the front edge of the module. If the end of the module is built wider than the 2 foot minimum, the common centerline does not need to be placed at the center of the wider module. It may be shifted to one side or the other as long as there is al least 2" between the edge of the bench work and the center of mainline #1.

PLEASE RESIST THE TEMPTATION to measure 2" and 3 1/2" in from the outside edge of the module to locate the track centerlines. We have found the chance for error in alignment of mainlines from one module to another is GREATLY REDUCED by measuring out from the centerline of the module. This is because the centerline, as a common point to align all mainlines from, prevents slight module width variations from becoming mainline alignment errors. One module's centerline will match another module's centerline even if the width of the two modules varies slightly. If this seems to be making a mountain out of a mole hill, please realize that you can't slide a module sideways to improve track alignment on one side without creating a misalignment on the other side if the mainlines were not located properly to begin with. Just a little care in the track laying stage will prevent any significant shimmy as a train crosses from one module to the next.

Mainline Clearance

The 1 1/2" of space between the two mainlines may be widened within the confines of the module to accommodate more track such as a yard or other scenery, but should not go below this minimum in order to insure proper clearance between equipment anywhere on the system.

If tunnels, bridges or any structures extending over the mainline are to be used, make sure that there is easy access in order to retrieve any derailment which might occur. There should be sufficient clearance for high or wide equipment such as double stack containers, long 90 foot "flats", 85 foot "hi-cubes" and passenger cars. Please note that double stack container cars are taller than passenger cars, hi-cube box cars and TOFC's (trailer on flat cars), and will need more height clearance than what is normally considered adequate, keep this in mind if you have any members who model the modern era.

Joiner Track

The track starts 2-7/16" in from the end of the module to allow for an Atlas 5 " straight section as a joiner track between modules. An Atlas 5" straight section is actually a little less than 5" long. This is why your mainlines should come a little closer to the end of the module than 2-1/2". That is why we have specified 2-7/16" from the end. After positioning the mainlines, nail in place at least 2" of straight track before any curvature of track begins. This will allow the track to remain straight, without a kink, when the joiner tracks are installed between modules. See FIG. #8. Extra track nails used in additional holes that you can drill in the ties are a big help in keeping the 2" minimum straight track in alignment if you use flex track all the way to the end. The best method though, is to use a short piece of rigid sectional track before the start of the use of flex track.  Also refer to the "Tips and Techniques" page for the tip on "break away tracks"

Mainline Radius

Track radius of mainline one or two shall not be less than 14 1/2" anywhere. Note that for outside curves the minimum radius for Main #1 is 16", and Main #2 is 14 1/2" to keep 1 1/2" track centers. For inside curves, Main #2 is now 16" and Main #1 is 14 1/2" to keep 1 1/2" track centers. See FIG. #8

Cork Roadbed

The use of cork roadbed is recommended, starting the roadbed at the end of the module and continuing across to the other end so that the roadbed stretches clear across the entire module. We have found that gluing at least the first 3" helps it stand up better to the increased ware and tear it will get from being at the end of the module.


Mainlines shall remain flat and level with no grades. No restrictions on any other tracks. If other tracks cross the mains, crossings should be level and true to the mainlines.


All turnouts that are a part of the mainlines or are used to diverge away from the mainlines shall be only Peco, Shinohara, Micro Engineering, or post 1994 Atlas Standard Line or Custom Line turnouts. The diverging route of the turnout should be a nominal #5, #6, or #8 for good rolling stock performance. Note: If a Peco #4 ("sharp") turnout is to be used on the mainline, then only the straight leg is to be on the mainline. Don't use the #4 Peco for crossovers between mainlines. The curved leg, being approximately 8" radius, is too tight to accept some equipment. All these turnouts are usually readily available. Peco, Micro Engineering, and Atlas Standard Line (with manual or powered switch machine) have points which snap and hold in place, thus reducing the chance of wheels picking the points and derailing. Shinohara and Atlas Custom Line (no switch machine) require the use of a ground throw or some kind of underground switch machine. Peco seem to be the preferred turnouts for most modular systems in N or HO that we have seen.

Crossings on Mainlines (Diamonds)

Atlas, Peco, or Shinohara crossings may be used. No hand laid Crossings.


Crossovers are not required on the mainlines, but we urge you to include at least one on one side of your module for future operational uses. Crossovers can use either a #8 (large), a #6 or #5 (medium), or a #6 Wye turnout (all are standard sizes in Peco brand), or equivalent sizes in the other brands. Do not use turnouts sharper than a #5 for crossovers as they may not handle all equipment. After the track has left either main you can use any size radius or brand of turnout that you wish. Turnouts and crossovers on mainlines may be powered if you desire, but are not required.

Scenery Track

Scenery tracks are defined as any track other than the mainlines, such as industrial spurs or yards.

Track Code

Scenery tracks may have any type of commercial track that is available. They may also be hand laid, if so inclined.


There are no radius restrictions on scenery tracks.


There are no grade restrictions on scenery tracks.


Turnouts used on scenery tracks can be any type of commercial turnout that is available. Scenery track turnouts may also be hand laid, and may have any radius or size.


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