Our Module Standards.
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The oNeTRAK module system is based on the NTRAK module system, but using one rather than three main tracks to more accurately represent typical North American Railroading. We have taken these standards and slightly altered them for our standards


i). Light weight, simple to build modules, especially for beginners or those with limited transport capability.

ii). Provide an alternative to a permanent layout, that will allow everyone to build a section at their own pace and be brought together for lots of fun!

iii). Provide a more prototypical operation which will involve main line and switching duties.

iv). A system that will allow different formations of boards and will allow easy expansion without having to alter anything already done.


1. HEIGHT OF TRACK - The base of the track (bottom face of sleepers, top of roadbed) will be 40 inches above the ground at the end of the module where it will attach to adjoining modules, what you do in the middle is up to you. To allow for variation in floors, you will need to fit adjustable feet to all module legs (available from SB group).

2. FRAME SIZES - Frame lengths are in multiples of one foot (usually 4 foot). Twelve inches are the minimum (preferred) width. This width may be increased up by another one foot, front or back for a total maximum width of three feet. Our basic standard module will be 48 inch (4 ft) x 12 inch (1 ft), modules of a different dimension are welcome though to add variety, however, the module geometry must confirm so that modules are in line with other mating modules. Please ensure all framework is square and especially that the vertical surfaces at the end of modules are in deed vertical so as to not leave any gaps when clamped to another module.


3. MODULE INTERFACE - The end of board dimensions are to be 12 inches wide, the adjoining boards are connected by G clamping. A 5 inch section of Peco track (cut from code 55 flexitrack) is used to join between the modules. To accommodate this, track must end 2.5 inches from the end of the baseboard. The frame on the module end is 1" x 3" timber or plywood equivalent. Modules are joined in a layout by clamping with two "G" clamps, one at the front and one at the back of the modules and inserting a 5" sections of Peco track. For connections between a dedicated pair of modules you may use butt joints if you wish. The joiners which will be used to connect the track, one set must be insulated to break the circuit and the other set need to be normal joiners to carry the current to the joining section of track, this is so as to make sure the only thing carrying the current across joins is the wiring underneath. If the join is between dedicated modules you can use 2 sets of normal connectors if you want to. Please ensure that there is enough clearance at the track end so that the rail joiner can slip easily into the mating track.

Important note: Leave plenty of space under the module ends so that clamps can be easily fitted, keep all wiring away from this area.

Clamping configuration

4. TRACK - Peco Streamline Code 55 track is standard.

The main track, which is mandatory, is the one 2 inches (measured from center of track) to the front edge of the baseboard and accommodates the 5 inch connecting tracks by finishing 2.5 inches from board end. Projections at front or rear are permitted. Double or triple track should have 1.5 inch center spacing at the module interface. All measurements are to the center of each track.

All turnouts should be the largest available on the mains, passing loops and interchange tracks. Medium turnouts are encouraged in yards, i.e. minimum - medium radius, preferred - large radius. Small radius should be avoided as these will cause long bogied wheelsets to derail.

All pointwork should have power routing applied to the frog so as not to rely on the switching blade to make contact and carry the current.

All track will be painted a weathered track colour and rails painted rust colour or similar (no shiny rails or plastic sleepers.)

5. MINIMUM RADIUS FOR CURVES - is 18 inches with appropriate easements. To prevent binding the minimum length of tangent between all reverse curves must be 5 inches.

6. CORNERS - Standard corners can be 30 by 30 inches, 3 ft by 3 ft (our preferred size) or 4 ft by 4 ft, etc. On a standard comer the track should be set back 2 inches from the nominal front edge. This makes layout design with inside corners easier. On a 30 by 30 inch comer there is ample room for the 18 inch radius curve and easements.

7. CLOSING LOOP LAYOUTS - Due to the wide variety of frame sizes and locations of tracks, some gaps may develop in a loop layout. Most large loops should be flexible enough to close a gap by "scrunching" the modules together.

8. JUNCTIONS - The smallest recommended junction is 3 by 4 feet.

9. GRADES - 2 percent maximum across a dedicated set of modules. Grades on other modules can be created with shims under legs of modules. Grades suggest addition of a helper district and helper engine facility.

10. END TURNS - Modules that include a 180-degree curve in the track. They should be a minimum of 3 by 4 feet to allow the 18-inch minimum radius and easements. The distance between the ends of tracks on an end turn must be three feet or more in even foot increments.

11. ELECTRICAL - Three electrical supplies are required on each module.

The SB group have a supply of free issue cable in the 6 designated colours for members building modules.

We recommend using Tapin Splice (Squires code CC0165) connectors to splice the buss cables to your layout.

i) DCC - this consists of two wires. One will be Red, the other White.  The wire nearest the front is the rail A feed and has the red connector. The wire furthest from the front is the rail B feed and has the white connector.

ii) 16v AC - Two wires for auxiliary equipment such as points motors. This can be arranged how you wish but must run the length of the module, even if you do not wish to use the supply yourself.  The wire colours will be blue and green, with blue nearer the front.

iii) 12v DC - supply for equipment such as signals, UP3/5 supply.  As with the 16v AC the wires must run the length of the modules and you can tap in as you wish. The wire colours will be yellow and black, with the yellow nearer the front.

See the wiring diagram at end for a visual configuration of wiring.

12. SCENERY - Any realistic scenery is permitted. Round down hills on the ends of modules so the view from an adjacent flat module looks like scenery. Do not use diorama dividers. Woodland scenic scatter material should be used to ensure that the modules blend with each other to a certain extent.

All scenic grass at module ends where it could attach to a different module at anytime, should be blended to match with Woodland Scenic T1349 green blend, this will allow modules to flow across joins.

Ballast for the main line will be Woodland Scenics Fine Ballast (gray blend) (B1393).

13. SKYLINE - Sky boards or vertical scenery flats (backboards) are required.  Backboards should be 9 inches high above the baseboard and be coloured with a sky blue colour, Dulux Jewelled Creek 4 30BG660975C6 matt emulsion. All members are requested to purchase their own tins to provide a good supply.

14. NON-LAYOUT TIMBER - All bare frame, surfaces and legs will be painted or stained black. This includes back of backboards and end of modules. A simple rule is if you can see it whilst 'playing trains' it must either be scenic or black.

15. PASSING SIDINGS - To enhance operations most or some layouts should include several passing sidings. A standard passing siding is a set of two 1 by 4 feet modules with turnouts at each end of the pair and double track connecting the turnouts. The resulting passing siding is about six feet long. Double or triple track modules can be used to extend these sidings.

16. OFFSET MODULES - These provide visual variety and should be in one foot increments. Observe 18 inch minimum radius and tangent track between reverse curves standards. Please remember you may have to make two of these to bring the layout back in line.

17. NEW MODULES - A basic sketch of your proposed modules should be submitted to members so that the group have an idea of your plans and may kick start another member into adding a complementary industry eg Cattle ranch goes with a Meat packing plant.

18. OPERATIONS SCHEME - Although a stated purpose of our standards is to provide a venue for more prototypical operations, no operational scheme is specified. Some times it will be operated with a dispatcher and/or a yard master. All public exhibitions which we are requested to attend will be operated and organised by a dispatcher.

19. MODULE DESIGN - oNeTRAK modules have proven very flexible in layout design both as part of a NTRAK layout or when standing alone, so we will use their basic designs for our modules.

Module layouts

20. WIRING DIAGRAM - Wiring Diagram for underside of each module. All modules should have all six wires under them feeding from one end to the other, whether you feed off the wires or not. All boards should have the common connection plugs and sockets as well, colour coded as below. The terminal blocks in the middle of the modules can be done away with providing another method of fixing is used, such as holes drilled through the framework and the wires fed through them to keep the wires separated.


Left Hand
Right hand
Wiring plan

DCC Rail A connection Min 1.3 mm

Accessories + (16V ac) Min 1.3 mm

UP3 Panel + (12V dc) Min 1.3 mm

UP3 Panel - (12V dc) Min 1.3 mm

Accessories - (16V ac) Min 1.3 mm

DCC Rail B connection Min 1.3 mm

Terminal Block–6 way 6 amp (minimum) rating

21. ELECTRICAL CONNECTORS - We will use 4mm diameter jacks and corresponding sockets (10 Amp rated) for connecting the various bus bars and common wiring, these can be obtained from the SB group. These will be colour coded to match the colour convention used to identify the wiring. Length of tails should be set at 15cm (6”). Please ensure that any exposed wire/soldering will not cause shorting.

“Male” connectors are to be provided at the LHS looking from the front of the module and “female” connectors provided at the RHS.

Female socket
Male jack

22. LOCATION NAMING - All module locations to be given names so as to ease the job of a dispatcher and when operating, it is easier to know where a train is going to, i.e Frysville grain facility.

23. DCC INTERFACE - Modules should have available on them a means to interface with the DCC system, this can be done via use of UP3 and UP5 jack points. To avoid using the built in power supply of the command stations these UP's should be wired into the system using the available 12v common wiring. Where practicable these should be mounted in pairs, one front and one on back of module to allow easy use and connected with a small connecting LocoNet cable to ease setup.

Please fit Cup hooks on the inside edge underneath your modules, this is so any cabling, i.e. loco-net, extensions or power feeds, can run the length of the layout and not rest on the ground where they may stood on or cause a tripping hazard.

24. DCC SYSTEM - We will use Digitrax as our main DCC system. All DCC components where possible will also be Digitrax for compatibility reasons and experience.

25. LOCOMOTIVES - You may use any chip manufacturer you like but we would like all chips programmed to correspond to the loco's number, 4 number programming, for ease of operation and also that they be altered to give a more authentic running performance. Once loco's are chipped and programmed their details should be forwarded to the locomotive database holder for entering into the database.

26. POINT OPERATION - Any method of turnout operation may be used but bear in mind it might not be you using it, so please make the method easy and simple to understand for other operators to use.

27. BRIDGE MODULE - If this module is in operation, use the following procedure

A - Ensure no trains are approaching

B - Fit the two barrier blocks

C - Remove the lift-out section

D - Replace the lift-out section

E - Ensure track is aligned

F - Remove the two barrier blocks

Please remember to take care when operating the bridge as trains cost money!

That's all for now.
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