HO Module Standards
Mohegan Pequot Model Railroad Club

Mohegan Pequot Model Railroad Club HO Module Standards

Adopted: September 1981, Last Revised: September 2014

1.0 Preamble

This standard applies to all modules used in HO scale Mohegan Pequot Model Railroad Club modular layouts. This standard is subdivided into definitions, train control, benchwork, trackwork, and electrical sections. This standard is applicable to modules upon which construction has not yet begun at the time the standards are adopted. It is recommended but not required that old modules be retrofitted to this standard.

This standard is based on three fundamental principles. First, creativity in module design and construction is encouraged. Second, mainline trackage will be designed and operated to optimize the continuous running of several trains on each mainline. Third, the design, construction, and operation of trackage other than mainline trackage are at the complete discretion of the module builder.

2.0 Definitions

2.1 Module The minimum unit into which the railroad may be disassembled.

2.2 Module Group The minimum unit in which the railroad may be operated. A module group may consist of 2 or more modules which cannot be operated without all the modules of the set.

2.3 Directions Left and right when used in this standard refer to directions on the module when viewed from the inside of the module. Inside refers to that side of the module closest to the operators.

2.4 Main Line Trackage Two continuous tracks required on each modules.

2.5 Non Main Line Trackage All trackage other than mainline trackage.

2.6 Bridge Track 6 inch sectional tracks which are temporarily installed between two adjacent modules for the purpose of connecting permanent trackage.

3.0 Train Control

3.1 Mainline Control Control of mainline tracks will be through the use of Digital Command Control using a system supplied by the club. Modules shall be wired so that it is not possible to power one mainline with power from the other. Control of mainline track from a local source is not permitted.

3.2 Control of Non Mainline Track Control of trains on non mainline tracks which is connected to the mainline, must be controlled via the DCC system. Trackwork not connected to the mainline may be controlled at the complete discretion of the module owner.

4.0 Benchwork

4.1 Connecting Modules Module groups will be connected with C Clamps. Modules within a module group will be connected at the discretion of the owner.

4.2 Height The height of the roadbed will be 40” from the floor.

4.3 Height Adjustment Module height shall be adjustable from 39 to 41 inches. If bolts and T nuts inserted in the end of the legs are used for height adjustment, the bolts shall be at least 4x5/16 inches.

4.4 Length Module group lengths shall be a multiple of 2 feet. The length of each module within a group is left to the discretion of the owner.

4.5 Width The width of a module is left to the discretion of the owner.

4.6 Corner Modules Corner modules shall be 50-inches by 50-inches from the abutting module face to the opposite outside face. Both inside and outside protruding corners should be cut off to reduce the size and weight and present a more uniform appearance.

4.7 Materials Materials shall be selected to make modules which are sufficiently flat, strong, and stable to permit trains to run without derailing or uncoupling.

4.8 Depth The depth of the module from the railhead to the bottom of the end framing shall be between 4 and 6 inches.

4.9 Ends, Thickness, and Obstructions The thickness of the ends of the benchwork shall not exceed 1” at the points where C clamps will be attached. The framework shall be constructed so as to allow for the easy application of the C clamp.

4.10 Color Benchwork shall be painted a semi-gloss dark forest green (example Glidden Semi-Gloss Interior Dark Forest Green)

4.11 Plexiglass Holder A holder for plexiglass shall be installed on the front face of the module. It shall be constructed to be 1.5” tall and 1” deep with a ¼” round over to take off the sharp edges on the plexiglass holder.

4.12 Skirting Hook side Velcro, at least one inch in width, shall be attached to both the front and back side of the modules to allow the attachment of skirting.

5.0 Trackwork

5.1 Trackage Trackage shall be code 100 nickel silver commercial flextrack. Code 83 nickel silver commercial flextrack is permitted so long as a transition section to Code 100 track is completed within six inches of the end of the module set. Grades and/or super elevation (banking) are not permitted.

5.2 Track Spacing and Setbacks There shall be two mainline tracks. Within 6 inches of the end of a module group, track shall be straight with a spacing of exactly 2 inches on center. Track spacing elsewhere on the module shall be not less than 2 inches on center.

Tracks shall end between 3 1/32 and 3 1/16 inches from the end of each module group. The centerline of the outside mainline shall be set back from the front of the module at least 2 inches if a plexiglass barrier is used or 5 inches if no barrier is supplied. The outside mainline shall not be set back more than 15 inches. It is recommended that the outside mainline be set five inches from the front edge of the module and the inside mainline setback seven inches from the front edge of the module.

5.3 Passing Track An optional passing track can be installed three inches on center from the inside mainline towards to inside of the module.

5.4 Track Curvature The minimum required radius of curvature on the mainline is 35 inches.

5.5 Turnouts Turnouts shall be Peco, Shinohara, or MicroEngineering. Other turnouts may be permitted upon request to the HO Module Coordinator.

5.6 Turnout Size When the diverging route in a turnout is used as mainline, turnouts shall be #6 (or Peco long) or larger.

5.7 Right of Way Clearance Any scenic, structure, or detail features (such as hills, overpasses, rock cuts, structures, signals, etc.) shall be installed to provide minimum horizontal and vertical clearance from the track centerline and railhead as provided by guidelines set forth from the National Model Railroad Association. Based on these standards, it is recommended that features be kept clear at least 2” horizontally from the centerline of mainline trackage as well as 3” vertically from the railhead on mainline trackage.

5.8 Insulated Rail Joiners Use The use of insulated rail joiners is required where electrical isolation is needed; air gaps are not permitted. Insulated rail joiners shall be used where necessary to prevent electrical short circuits. All points of intersection between the inside and outside mainline and either mainline and any local tracks shall have an insulated rail joiner on each rail.

6.0 Electrical

6.1 Track Voltage Service Each module shall have electrical service to transmit track voltage to the next module as well as to mainline trackage. Breaks in these conductors shall be minimized. Where broken conductors shall be joined with a plug, e.g. section 6.32 or a solder joint.

6.2 Track Voltage Service, Plugs Plugs (male end) shall be 9-Pin Tyco CPC Connector 1-211768 with Tyco CPC Cable Clamp 1-206070-8 or equivalent. Receptacles (female end) shall be 9-Pin Tyco CPC Connector 1-211769-1.

6.3 Track Voltage Service, Wiring Size Wiring for the transmission of power between modules shall be of at least 14 gauge. Wiring for local use within a module group shall be of at least 20 gauge.

6.4 12 Volt DC Service Each module shall have 12VDC service consisting of a +/-12VDC. The wiring shall be included in the same harness which provides the track voltage service. 12 Volt DC wiring shall be 22 gauge stranded copper wire.

6.5 Wiring Harness Wiring harnesses constructed in accordance with sections 6.0 will be supplied by the club at the module owner’s expense.

6.6 Control Panels Each module which is equipped with a removable control panel shall be wired such that the module may be run without the control panel.

6.7 Mainline Track Power Bus The Mainline Track Power Bus is a six wire bus which provides power for all module trackage from the command station. It shall be constructed of 14 gauge electrical wire with the following color scheme: red, gray, green, yellow, black, white. The wires shall be hooked up to the module trackage in the following configuration:

6.7.1 Red wire – Outside mainline – front rail

6.7.2 Gray wire- Outside mainline – back rail

6.7.3 Green wire – Inside mainline – front rail

6.7.4 Yellow wire – Inside mainline – back rail

6.7.5 Black wire – All local tracks – front rail

6.7.6 White wire – All local tracks – back rail

6.8 Twisted Pairs The following pairs of wires for each set of connections need to be twisted – red and gray, green and yellow, as well as black and white.

6.9 Power Bus Wiring Scheme The wires will be connected between modules using connectors specified in 6.5. The following pin numbers shall be used for the wires:

6.9.1 1 – Red wire-14 gauge (Outside mainline – front rail)

6.9.2 2 – Purple wire-22 gauge (+12VDC)

6.9.3 3 – Gray wire-14 gauge (Outside mainline – front rail)

6.9.4 4 – Black wire-14 gauge (Local tracks – front rail)

6.9.5 5 – Orange wire-22 gauge (12VDC Ground)

6.9.6 6 – White wire-14 gauge (Local tracks – back rail)

6.9.7 7 – Green wire-14 gauge (Inside mainline - front rail)

6.9.8 8 –Brown wire-22 gauge (-12VDC)

6.9.9 9 – Yellow wire-14 gauge (Inside mainline – back rail)

6.10Cab Bus The cab bus is a CATV cable that runs along the back of the module. RJ-12 plugs and receptacles shall be used with the receptacles attached with standard electrical boxes. The wiring pattern for the plugs and receptacles shall be clockwise from left to right as follows:

6.10.1 Blue

6.10.2 Blue/White

6.10.3 Orange

6.10.4 Orange/White

6.10.5 Green

6.10.6 Green/White

6.10.7 Do not use Brown and Brown/White