N Scale Module Construction Journal

Ottertail Creek Bridge (free-mo N, mini-mo)

Wesley Steiner

Last Updated: 22 Apr 2005

This document attempts to capture the design, construction and development of my Ottertail Creek Bridge free-mo N scale module. The Ottertail Creek Bridge is a 120 ft. steel girder span over the Ottertail river in central British Columbia, Canada.

A mini-mo is a free-mo module designed to extend the distance between the main free-mo modules (yards, towns or industries) as quickly and cheaply as possible. They are usually only 12 in. wide, incorporate a slight turn, have a single main line w/o turnouts and do not have permanently attached legs. These features make them inexpensive and quick to build. I like to add at least one main scenic feature to my mini-mos so in this case it will be a model of the Ottertail Creek Bridge over the Ottertail river in central British Columbia, Canada.

Here the basic module frame has been completed and the foam sub-roadbed surface has been rough cut to shape. The module has an approximate 32 degree turn. As you can see most of the module is built up from foam and the two wooden end-plates. This construction technique results in an extremely light weight module for ease of transportation and handling during set-ups.

In this photo the foam surface has been shaved with a foam rasp to near final shape.

Foam is being added to support the river basin. I use Liquid Nails for Foamboard to glue the foam pieces together. This photo also shows how the end-plates are constructed. Longitudinal support will be provided later with the addition of fascia material and stringers if necessary.

Final shaping of the curved module sides is complete and a rough outline of the landscape topography has been sketched out from the prototype photos. Also the roadbed has been glued in place in preparation for shaping the landscape.

This photo shows the module after rough cutting the lanscape with a utility knife. An extra piece of foam has been glued to the top for a small hill area. Most of the contours have been rough cut to shape and the bridge area has been removed.

Here final shaping of the landscape is complete. I use a foam rasp and sandpaper to get as close as possible to the final countours.

... stay tuned here for progress updates ...