Page Revised 6/1/2015
Module Standards
Standards Revised 4/6/2009 -- Rev 2C
The purpose of these pages is to establish a uniform set of standards and specifications for the construction of modules suitable for an HO gauge model railroad club. These standards should be a helpful aid to the beginner, as well as being guidelines for the club.
In these documents, any paragraph which starts with a pound sign (#) is a requirement.
Module Concept
- Expandable in all directions.
- All modules are fully portable.
- All modules are relatively equal in size.
- Large radius curves
- Realistic operation with prototype length trains. Constructed from readily available materials and quickly assembled for operational display purposes. Two continuous loops that will allow the normal two loop operation or a more elaborate switching operation.
- Designed for:
- Individual home layouts where mobility is a factor.
- Club members to gather together to set up a temporary layout.
- Regional meets where large spaces are available.
- Provide a basic foundation for all modelers, regardless of skill, to display their likes and talents.
- Flexibility to change with new innovations and developments.
Drawings will be continuously revised and updated to reflect changes.
Radically new designs must be discussed with the Standards Committee.
Construction Guidelines
The following requirements have been separated into six groups.
Each topic is a step in the construction of a module.
Each step is listed in the order of its occurrence.
# Anything not built to standards must get a variance from the Standards Committee.
The club members desiring help in the area of construction of a module may call on the Standards Committee.
Finished modules are to be provided with the necessary 6" connecting tracks, metal rail joiners and 3" c-clamps, which will be provided by the club .
# Modules shall be a multiple of 2’ long and 24" or 30" wide.
Woodworking
The module frame can be of 1"x6" construction grade or better wood, straight and solid material, free of excessive knots and selected for strength and appearance.
# The module surface shall be constructed of any of the following materials:
- Oriented strand board (OSB) of 7/16" thickness, min.
- Plywood type A/D grade or better, 1/2" thick covered by Homasote of 1/2" thickness.
- Sheet foam insulation of 2" thickness recessed so that surface is recessed level with top of module frame. Gussets mounted 2" below top of rail frame will be required for foam support. (See: Figure #1 - Standard Straight Module1)
The hardware indicated on the drawings is available at most hardware stores.
Provide sufficient data for assembly so that persons other than the builder may assemble the unit.
Skyboards are optional. They should be removable except if they are a permanent part of the diorama scene on the module.
# The sides and legs shall be painted black. Paint shall be provided by the club.
Gusset plates are to be attached to the tops of the leg clamp areas (see: Figure #1 - Standard Straight Module, Figure #2a - Corner Module, Figure #2b - Corner Module, Figure #3b - Corner Construction) This will prevent pushing foam bases up and causing tracking problems.
Trackwork
# The mainline tracks shall have 0% grade and a constant elevation of 0 inches (except on the permanent layout). Other tracks have no grade or elevation restrictions.
# Curved tracks on corners shall have a minimum easement of 1" of straight track at each end to eliminate derailment problems. (See: Figure #3a - Small Corner Module)
#The spacing of mainline track is 2 inches centerline to centerline at the end of a module, and must have a 2 inch minimum spacing throughout. All other tracks have a 2 inch centerline Eastbound mainline track must be 5 inches at centerline from edge of module.
# Mainline tracks must be code 100 nickel silver and can be either pre-assembled on plastic ties or hand laid on suitable wooden ties. Other tracks have no restrictions.
# Turnouts used on the mainline for crossovers or passing sidings must be Peco "long" at the minimum. For sidings off the mainlines, there are no restrictions on turnout types or size.
# The only uncoupler that may be used on the mainline is the Kadee electromagnet type mounted under the track. Other tracks have no restrictions.
# The rail ends shall be securely fastened to the roadbed for positive alignment. Provide access to all trackage for maintenance purposes.
# Mainline track shall end 3 inches from each end of the module. Two 6" Atlas Snap Track modified sections shall be used to connect the mainline tracks together. These connecting track sections are adjustable to help with warpage.
# Mainline switches ending 6 inches from the end of a module require a 3 inch track section be added to the end of the switch. The switch and the 3 inch track section must be securely fastened to the roadbed to accommodate the 6" Atlas Snap Track jumpers between modules.
# Insulating gaps shall be used at all crossovers and at any track connection to either of the mainline tracks. The location will vary with the type of control and the individual design of the trackage of the module. If insulating rail joiners are not used, the cut rail shall be held in gauge with epoxy or equivalent cement and the gap filled with insulating material.
#Crossover switches should be of the trailing point installation wherever possible on modules. (See Figure #6 Trailing Point Crossover)
# The corner module curves shall be of 38" radius for the inner (Westbound) track and 40" radius for the outer (Eastbound) track. Transition curves may be used in place of the circular arcs.
Use of the "bent stick" method to establish a template for corner module curves is recommended.
# The sidings off a curved mainline shall be accessed only with the use of a Peco curved turnout. The long minimum applies to these turnouts.
Wiring
# For analog(DC) operation, each module must supply its own electrical power for any of its diorama trackage, if operation is planned. Module power must also be used for any accessories and turnout actuators. Mainline power can be used to power a siding only if a siding track POWER On/Off switch is installed and appropriately marked. The module power cannot be used to control the mainline tracks. (See: Figure #4 - Module Wiring)
# It is required that #14awg minimum stranded wire be used on all connections with the exception of the power connection to the rails, where a lighter gauge wire may be used. Solid wire is not to be used.
# All electrical connections shall be soldered or fastened with approved crimp style connectors.
# All wire splices shall be soldered and taped or covered with heat shrink tubing, however, crimp style insulated butt splices may be substituted.
# Wiring using crimp connectors shall be closely inspected by the Standards Committee for compliance with club standards. (Proposed)
# All wiring shall be securely fastened to framing material. Provision shall be made to secure all cable ends above the bottom edge of the module frame for transportation. Method used is optional. (Velcro straps suggested)
Cable all wiring whenever possible and protect all wiring from damage.
# The four terminal color-coded Anderson Power Pole hereinafter called APP connectors shall be used for mainline track power to insure uniformity.
# The female socket APP connector shall be used on the West end of the module and the plug type APP connector shall be on the East end of the module. These are available through the club.
# Color coding of the connectors and wires in the cable shall be as follows:
Track Pin Color
Outside Main,
Outside rail 1 White
Outside Main,
Inside Rail 2 Red
Inside Main,
Inside Rail, 3 Brown
Inside Main,
Outside Rail 4 Yellow
A color-coded track diagram should be provided on the back of the skyboard or on the control panel.
# An electrical wiring diagram must be made available for troubleshooting purposes. When numbering tracks on a module, the Eastbound main track becomes the No. 1 track and the track numbers increment sequentially toward the innermost track (viewing side). Any tracks located outside The Eastbound main track are numbered sequentially from the highest numbered inside track. The main lines are labeled as Eastbound (No.1 Outside) and Westbound (No. 2 inside). (See: Figure #4 - Module Wiring)
# All switches and controls shall be clearly labeled and keyed to the track diagram. The diagrams should be easily understood by anyone and should allow them to operate the modules unaided.
# Minimum size wire for rail drops shall be #22awg stranded. Connection to rail drops using #18awg wire must be soldered and taped or crimped with approved terminals.
Track Switch Wiring
# Peco switch machines shall be wired in accordance with the following method. (See: Figure #5 - Peco Switch Machine Wiring).
- Connect a red 22awg (min) wire to terminal "A"
- Connect a green 22awg (min) wire to terminal "B"
- Connect a blue 22awg (min) wire to terminal "C" with a blue short jumper to terminal "D"
- All leads to be at least 18" in length.
NOTE Red lead terminal "A" faces outer straight rail side of track switch. Green lead terminal "B" faces outer curved rail side of track switch.
Scenery
All main lines and sidings should have ballast. It is recommended that the track be fastened with the bonded ballast method. The ballast on the main lines should be a mix of fine and medium texture so as to blend together with adjacent modules. Ballast on all other tracks should be what is scenically appropriate.
# All tracks must be fastened down securely and only the connecting tracks may be removable.
# Area above main line tracks must be clear for a minimum of 25 scale feet (3.5 inches) to clear double stack and other excess height cars.
# Permanent scenery elements must not extend more than 12 or 24 inches above the bottom of the module so that the module can fit into the trailer racks without interference or damage. Scenery elements above this height must be made removable for transport in the club trailer.
There are no other limits on scenery except for height above track level. (Check Diorama and NMRA Clearance Specs.)
Protection
It is recommended that each module have a plexiglass front to provide protection from viewers’ hands.
Layout
# The mainline tracks shall be continuous and form two unbroken loops of track. The inside track is the Westbound track and will operate in a clockwise direction. The outside track is the Eastbound track and will operate in a counter-clockwise direction. North is the operating side of the diorama and South is the viewing side. (See: Figure #4 - Module Wiring)
An operating manual will be published to cover the Normal and Switching operations.
Non-Standard Modules
Non-standard module shapes must meet the same Standards requirements in all other areas and require the Standards Committee approval.
Module Registration
The purpose of the registration is to provide a record of compliance. It also provides information regarding the industry on the module, the size of buildings, if any, and if the module is a standalone unit or requires one or more other modules.
New modules will be inspected by the Standards Committee for compliance with club standards. When the inspection has been passed, the module will be issued a number and entered into the club registry.
A database of this information will be kept to assist in assembling modules for club shows.
Rolling Stock Requirements
# The minimum weight of a car shall conform to NMRA standard weight. The NMRA formula is one ounce plus one-half ounce per inch of car length.
| Car Length (inches) |
Car Length (Scale Feet) |
NMRA Weight (Ounces) |
|---|---|---|
| 3 7/16 | 25 | 2.75 |
| 4 1/8 | 30 | 3.12 |
| 5 1/2 | 40 | 3.75 |
| 6 7/8 | 50 | 4.38 |
| 8 1/4 | 60 | 5.12 |
| 9 5/8 | 70 | 5.75 |
| 11 | 80 | 6.3 |
Additional weight may be added, but too much weight could damage the trucks especially plastic trucks.
All equipment must be provided with Kadee compatible couplers. The exception is for "unit trains" e.g. coal trains, auto racks & roadrailers. In this case, each end car must have Kadee compatible couplers.
Permanent Layout Module Specifications
CONSTRUCTION
- Make each framework section moveable while meeting the needs of the Club. Sections should be not more than 8 feet in length.
- Special sections such as multiple track sections should be designed to be removable separately if a Club move or layout changes are made necessary.
- UP5 units will be added to new construction as the need arises.
ELECTRICAL SPECIFICATIONS
- Mainline feeders should be a minimum of 14awg copper wire using existing standard modular colors. (See Page 6 Standards)
- Terminations should be made using barrier strips at each end of the section. Jumper wires will be used to connect each section to the other. An alternate to the jumpers would be short cables using connectors such as Anderson Power Poles.
- Track feeders must be no more than three (3) feet apart, maximum.
- Special electronic modules may be installed to facilitate remote operation from the Club computer when required.
TRACKWORK
- Main Lines shall be code 100 rail using ready-made track or hand laid.
- Main line switches shall be Peco long or greater radius or length, unless hand fabricated. There are no restrictions on siding switches.
- Sidings may be freelanced with any size commercially available rail.
- No restrictions on track elevation other than train capability, preferably no more than 2% grade.
Diagrams
Figure #1 - Standard Straight Module
Figure #3a - Small Corner Module
Figure #3b - Corner Construction
Figure #3c - Corner Dimensions - Top View
Figure #3d - Corner Dimensions - Side View
Figure #5 - Peco Switch Machine Wiring
Figure #6 - Trailing Point Crossover
Figure #7 - Wiring Peco Turnouts
Figure #8 - Traveling Layout Wiring Schematic