Important note - while the standards below are accurate, they are presently incomplete. We are in the process of upgrading our single track modules to make them fully compliant with Free-mo in addition to remaining compatible with our own equipment. That information will be added as soon as it becomes available.

One of the two formats for module construction is the Northwest Trainmasters/Free-mo style. It is closely based on a format called Free-mo that uses a single track mainline. Some of the Free-Mo standards have been modified to adapt to our preferences and restrictions. One of the significant differences is the base rail height being set at 40" instead of 50". Another is setting the minimum mainline curve radius at 36" instead of 42". However, modules done in our format will still interconnect with standard Free-Mo modules if they're set to a 50" rail height. Additionally, we established our version of Free-mo style when Free-mo itself was still quite new. Free-Mo has continued to evolve and as a result our modules are without some of the features of a fully compliant Free-Mo module. Complete information about a fully compliant Free-mo module can be found at the website that inspired us, which is at : http://www.free-mo.org/.

Benchwork

• Mating ends of modules shall be 1"x6"lumber and are to be 24" wide. C-clamps will be the normal means of connecting modules.
• The nominal height to the top of the rail from the floor is 40". Minimum height of the rail is 40" and maximum height is 52".
• The module must be able to stand alone, and in most cases should have at least four legs.
• Legs will have capability for adjustment of ±1". The legs of the module may be constructed to provide the capability of adjusting the height of the module in 3/4" increments to align it with an adjacent module that includes an elevation change.
• Roadbed will be mounted on plywood or other rigid and durable material, braced to prevent sag or flexing.
• All exposed edges of a module shouldbe finished for appearance, as all sides are likely to be visible.

Track

• A single standard gauge mainline will be used. Club owned modules will use Code 83 nickel-silver rail for their mainlines and is the preferred code for member's modules.
• The mainline will be centered on the 24" end, and will be perpendicular to the end. It will run straight and level for a minimum 6" from the end.
• Rail will be cut 1" from the modules end, but ties, ballast, and roadbed will continue to the module's edge. A 2" piece of Code 83 rail with sliding rail joiners will be used between adjacent modules to connect the rails.
• MINIMUM radius of mainline curves is 36", with at least 12" of straight track between reverse curves. Transition curves are recommended to ease long cars in and out of curves.
• Grades in the mainline are permissible and are limited to 2.0% maximum. On modules with grades, the change in height between any two ends shall be a multiple of 3/4". Modules must always be capable of being adjusted to minimum height on the lowest end when an elevation change is present.
• Vertical curves (changes in grade) on the mainline must be appropriate for operation of long vehicles. Superelevation (banked curve) is not recommended.
• Turnouts (switches) on the mainline shall have #6 frogs or larger. All mainline switches and turnout controls should be clearly marked so that they can be operated in the module owner's absence.
• Both rails of the mainline will be electrically isolated from all other trackage on the module. Isolation gaps will be filled with an appropriate nonconductive material. No air gaps are allowed.
• For reliability reasons, sectional track and hand laid track are not recommended. Members who are skilled at hand laying track are not discouraged from using hand laid track, but should use their discretion as to where and when its use is appropriate.
• Club owned modules will have the MAINLINES ballasted with a medium gray, small size (N-scale) ballast that matches either:
  • a.) AZ Rock & Mineral's "Northern Pacific #130-1
  • b.) a 50-50 mix of Woodland Scenic's "Light Gray, Fine #785-74" and "Gray, Fine #785-75"
• Uncoupling ramps in the mainline should be electric or, if permanent magnet type, mounted to drop away or be easily removed.
• Powering of switch machines, building lights, etc., is the responsibility of the individual builder and should be separate from circuits which interface with other modules in a layout.
• Any trackage that is not mainline is not covered by Single Track Module Standards and is left to the discretion of the individual or group.

Wiring

• Wire used for power distribution in the mainline shall be #14 awg stranded or larger. Feeder wires shall be #24 awg or larger. Distribution wire will be firmly attached beneath the module and should terminate at each end in a terminal block.
• These terminal blocks will also retain a pair of two conductor Cinch-Jones type connectors, one male and one female. When facing the end, the mainline's right side rail will be connected to pin #1 (wide blade) of the female connector and to pin #2 (narrow blade) of the male connector. The left side rail will be connected to pin #2 (narrow blade) of the female connector and to pin #1 (wide blade) of the male connector. This arrangement will be repeated at all mating ends in order to permit the module to be installed in any orientation. The connectors should extend beyond the module's edge by an amount reasonable for interconnection of adjacent modules.

last update: 06 Mar 2009