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  • Atlanta Interlocking Model Railroaders

    By David Butts
    Photos by the author

    Modular model railroading is a great way to get involved in the hobby of model railroading, as shown by the photographs in this article. A module is an interchangeable section of railroad built to certain standards — NMRA, FREMO and/or other. Building a module helps a modeler to develop skills and learn techniques. Moreover, in a club environment, such as Atlanta Interlocking Model Railroaders, modular model railroading allows for fellowship and the ability to pool resources to accomplish more than one person could normally accomplish alone. Modules can become the nucleus of a home layout and, because they are portable, can be displayed individually or combined to make display layouts at train shows and other functions. If that is not enough, building a module is not an overwhelming task. Modelers can have a sense of completion sooner, as each module is finished, than they could achieve if they were building a basement empire.

    CNW 4323 switches out loaded covered hopper at cement plant. R. Schaefer module.

    The Club

    Randy Schaefer and Norm Wizner formed Atlanta Interlocking Model Railroaders (AIMR) in 2001. Randy and Norm felt that there was a need in the greater Atlanta area for a HO modular train club committed to excellence. The goals of the organization are to display a visually pleasing, viewer friendly, modular train layout at train shows such as the Greenberg Train Show and GATS (Great American Train Show); have nicely detailed, consistent scenery; facilitate prototype operations; and provide a forum to promote the hobby. For the past two years AIMR has also participated in a local train show sponsored by Smoke Rise Baptist Church in Stone Mountain, Georgia. This event normally takes place in late July and is a combined effort with other modular railroad clubs in the region.

    CNW locomotive works the paper mill. R. Schaefer module.

    A trademark of the club is that it displays new modules and layout configurations at each show. So there is never the same layout at two consecutive shows. Moreover the club is not limited to rectangular layouts but has the capability to set up reverse-loop-to-reverse-loop layouts thanks to the incorporation of junction modules. The modular layouts can range in size depending on the space available but usually occupies a 40' by 40' space. The train show season runs from November through March and between train shows a modular layout is set up in Randy’s basement for operating sessions.

    CNW locomotive sets out gondolas with loads at pipe manufacturing plant. R. Schaefer module.

    Member Profile

    Currently the club has ten members, Charlie Crawford, David Butts, Gary Farino, Don Gabler, Pat Parker, Joe Schaefer, Randy Schaefer, Barry Schumacher, Trey Washington and Norm Wizner. The club is informal and has limited rules with the exception that all members must have a minimum of 10' of modules and be participatory in train shows. Members are encouraged to be scenically creative with their modules and most of the modules are designed with prototype operations in mind. As a result many of the modules are industry oriented and have sidings and crossovers to facilitate car forwarding and train meets.

    The membership has a wide range of prototype interests from the early 1900s to the present. Train models from Amtrak, Boston & Maine, CB&Q, Central of Georgia, Chicago & North Western, New York Central, Santa Fe, Burlington Northern, Southern and Union Pacific are represented. Normally during a train show the club tries to run equipment of the same era so there will be periods during the show where steam, transition era or modern-era equipment is run.

    Farm scene complete with irrigation system. On the road next to the field are US Army trucks returning to the post.

    Module Construction and Track 

    Module design loosely follows NMRA standards. Tracks are laid 5", 7" and 9.5" from the outside edge of the module. Members have modules ranging from 2' x 2' to 2' x 10' though the average size is 2' x 6'. Normally half inch plywood sheeting is used for the top of the module and dimensional lumber is used for the sides and framing. Modules are glued and screwed together for rigidity. Leg pockets are made out of 2x4 lumber and the legs themselves are made from 2x2 lumber with eyebolts and T-nuts or rod couplings added to the bottom of the legs to facilitate adjustments. Layout height is 40" from the floor. Code 100 flextrack from Atlas with Peco code 100 turnouts is in use. However, some of the members are gravitating toward code 83 track that requires the use of conversion tracks to make all of the modules interchangeable. One of the members, Don Gabler, has even built modules with handlaid track on stained wooden ties.

    Northfield Flour Mill is worked by the company RS3 locomotive. N. Wizner module.


    NYC 1219 switches boxcars at the building supply warehouse. D. Butts module.

    The Modules

    AIMR has approximately 600 linear feet of modules at its disposal. This includes straight sections, curved sections and specialty sections (return loops, junction modules, and FREMO interchange modules). Individual members own all of the modules. Most of the modules are either double-track or triple-track with quad track or more in the heavy industrial areas. Some of the members have become interested in single-track railroading and modules reflecting this have been built. Scenes on the modules encompass towns, heavy industrial areas, rural/farming, lumber mills, petroleum tank farm, grain facility, asphalt plant, and other types of industries.


    Digitrax DCC is used to power the modular layout. Members use both radio and traditional, non-radio Digitrax DCC throttles, DT400s, DT300s and UT1s. Digitrax UP3s or UP5s are installed on modules to provide throttle ports for walk-around capability for non-radio throttles. Normally the layout is divided into three power districts, each with its own booster. Reverse loops are controlled using auto reversers from MRC and Tony's Train Xchange. Automotive-style plugs and sockets are used to provide electrical continuity between modules. The wire buses are made from 16- or 18-gauge wire. Most of the turnouts are thrown manually with ground throws by Caboose Hobbies though some of the members have employed stationary decoders from NCE and switch machines (Switch Master or Tortoise) to automatically throw turnouts.

    Scenery and Structures

    In order to have consistency, all of the members model the spring or summer for their modules. Thus the coloration of the modules tends to be various green, yellow and brown blends. The ballast used is Woodland Scenics medium grit in the gray blend. Foam board is preferred for use in making terrain contours, rock cuts, hills and mountains as it is lightweight and flexible.

    Structures run the gamut from kits, kitbashes, to scratchbuilt. Many of the members are keen on building scratchbuilt structures because it allows them to custom tailor a structure for the location. Plastic structures are most common, but some of the members are adept at using wood and foamcore board to built theirs.

    Motive Power and Rolling Stock

    Diesel locomotives are the dominant form of motive power in the club, though some members focus on steam. Most of the diesels are plastic products from Atlas, Athearn, Proto 2K, Kato and Spectrum. Some of the members custom paint and superdetail their locomotives. The steam locomotives range from brass to plastic products.

    Rolling stock is mostly plastic products. Further, several of the members custom paint, superdetail and even scratchbuild their rolling stock. In particular, Charlie Crawford and Randy Schaefer have scratchbuilt specific rolling stock based on the prototype from photographs and actual designs.

    NYC Ten Wheeler crosses bridge on the Michigan Central with way freight.


    The operations goal at a train show is to have the maximum amount of trains moving for the audience or viewing public. DCC facilitates train volume and typically six to eight trains are moving at any given time. To stimulate member interest, car forwarding is factored into the session. To keep it simple and eliminate paperwork in a show environment, trains, primarily way freights, are staged in the yard and set out and pick up like cars from the industries on hand and return to the yard. For instance, one of the members, Charlie Crawford, has modules representing a complete lumber mill facility, and log cars are loaded at the log pond and the loaded cars are transported to the lumber mill. This has really proved to be a treat for the viewing audience as they get to watch trains operate as opposed to just running in circles.

    Example of module wiring, power bus, drops, terminal strip, automotive socket, 2x4 leg pockets and Digitrax UP3 installed.

    Freight trains are the current focus, but the members are moving toward including passenger-train operations in the scheme of things. Several members have modules with online passenger stations. Gary Farino has built an 18' long set of modules depicting an Amtrak station in Northern Virginia based on Walthers kits. Moreover, under construction by Pat Parker is a stub-end style passenger terminal with a turntable. This scene will be in excess of 20' and be able to service complete train sets.

    In the basement environment at Randy Schaefer’s home operations are more comprehensive. The track layout using modules and permanent pieces is pure point to point, with a transfer yard in the center of the layout and two staging yards, one at each end of the layout. Car forwarding using a car-card system, waybills, track warrants and CTC is employed. Randy designed a working signal system using toggle switches to facilitate train movements under CTC with searchlight and other signal types. Two-man crews are the norm, engineer and conductor/brakeman. Train operators communicate with the dispatcher and each other using walkie-talkies or radio headsets.


    If you are in Atlanta during the fall or winter when the Atlanta Interlocking Model Railroaders are participating in a Greenberg Train Show or Great American Train Show please stop by to see us. We enjoy providing a viewer-friendly modular train layout with lots of action and nice scenery. And we love talking to fellow model railroaders and model train enthusiasts. In conclusion, modular railroading is a great way to get started in the hobby of model railroading. They don’t consume a lot of space, can be built on a workbench, are portable and can provide the nucleus of a home layout. Special thanks to Bill Ello and Peter Youngblood for their help and technical support.

    Module under construction, size 30” wide by 4’ long, track installed and painted, wired, and foam board terrain started.

    Article Details

    • Original Author David Butts
    • Source Model Railroading
    • Publication Date July 2004

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