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How to Build a Model Railroad Track Bed

A model railroad track bed consists of a sub-roadbed, a raised bed of cork upon which the track is laid, ballast spread over the track (the simulated gravel between the ties and around the rails) and cork to complete the grade. The sub-roadbed could be a flat 4 foot x 8 foot sheet of plywood, or it could be cut strips of plywood positioned on inclines in an open benchwork to create elevation in the layout. In recent years, extruded foam, found in home improvement stores as 4 foot x 8 foot sheets of pink insulation, has become increasingly popular as a base for track and scenery because it's light, easy to shape and easy to work with.

Things You'll Need

Extruded foam
T-pins
Hot-wire foam cutter
Liquid Nails adhesive
White glue
Rubbing alcohol
Water
Ballast

Instructions

- 1
  Place a layer of extruded foam directly on the plywood surface of your layout's benchwork, and layer more foam pieces on top of it as you build elevations for your layout. You can glue the base layer to the plywood, but it's best not to glue the other pieces down until you're satisfied with the plan. Using foam inclines available from Woodland Scenics is an easy way to increase a track bed's elevation with accurate grades that are not too steep. A 4 percent grade is the highest you should go. Less is better.
- 2
  Position the track loosely, using long T-pins to temporarily place the track as you fine tune your layout plan. Shape foam pieces as necessary using a foam hot-wire cutter available from hobby stores. Mark the placement of the foam pieces and track until you're satisfied with the look. Mark track placement with a felt tip pen by placing dots between the ties and halfway between the rails.
- 3
  Remove the track, and glue the foam pieces directly to each other using an adhesive such as Liquid Nails. Make sure the placement of inclines between elevations is accurate before gluing.
- 4
  Place cork roadbed along the track route. The roadbed comes in strips of 36 inches, and splits in the middle to create two pieces per length, with the beveled edges going toward the outside. Glue down one side of the cork, with the inner edge following the dots of the track layout. Glue the other half of the strip against the first.
- 5
  Lay and glue the track onto the cork roadbed, using a a ¼ dilution of white glue mixed with water and a small amount of rubbing alcohol to make the glue spread easily. Secure with T-pins until dry.
- 6
  Spread ballast along the inside and outside of the rails, following the shape of the cork roadbed. Keep the ballast at or slightly below the top level of the ties, and be sure any ballast is clear of the working points in track turnouts (switches). Place drops of the glue solution between the ties and along the sides to keep the ballast in place and securely cement the tracks in place. Wipe off any glue from the top of the rails, and again, keep clear of working points in turnouts. Let dry.

Model Railroads