Model Description (sample)

This is my written description of how I've built the bridge for the Master Builder Structures Certificate. I have written similar descriptions for all of my models although less might be sufficient. The important thing to remember is to point out special features or methods that are probaly not evident to the judges. A list of all commercial parts is always required and should be as complete as possible.
Photos of the prototype and drawings that were used to build the model must also be included.

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BRIDGE for a country road

1. CONSTRUCTION

      To build the bridge I:

-          followed a drawing from the Kalmbach book “Bridges and Trestles”

-          Cut and fit stripwood with a NWSL chopper

-          Scratchbuild and weathered

First I weathered all wood parts with a wash of diluted India ink.

After the weathering had dried I cut the bridge planks to size and placed them side-by-side on a piece of tape glue.

Then I cut the supporting beams to length and glued them equally spaced to the planks.

Then I cut the beams for the triangular bridge truss, bevelled the ends and glued the pieces together in a jig.

After the bridge assembly was dry I glued a plank 16 scale inches longer than the bridge planks on either side of the bridge for support of the truss assembly.

I cut the kingpost beam to length and glued it in the center of the bridge.

After the truss assembly was dry, I glued both parts to the support planks and centered everything over the kingpost.

The bridge is held together with metal rods and stringers.

I simulated the different iron straps and plates with small pieces of strip styrene

I drilled appropriate holes and threaded brass wire through the holes to simulate the different rods as per the drawing.

2. DETAIL

      To visualize the bridge, I mounted it on a small display. I cut 2 pieces of wood for the       abutments and fixed Faller Decorative Sheets “Natural Stone” to theses abutments to represent         the random stone pattern. Then I shaped pieces of Styrofoam to represent the sloped terrain. I      covered the scene with different scenery materials. A small riverbed adds to the purpose of the         bridge.

      Parts list

      Northeastern Scale Lumber     3014    2 x 8

                                                     3041    6 x 8

                                                     3034    4 x 12

                                                     3043    6 x 12

      Detail Associates                    2507    0.015” brass wire

                                                     2505    0.010” brass wire

                                                     2506    0.0125” brass wire

                                                     2206    Eyebolts

      Woodland Scenics                              Fine turf

      Faller                                      170802            Decorative Sheets “Natural Stone”

      Miscellaneous                                     strip styrene pieces

                                                                 Tile mortar for ground cover

                                                                 Sifted Sand and different sizes of gravel

                                                                 Two component epoxy for the water  

3. CONFORMITY

      This bridge was located somewhere in Ohio. These wood bridges of the kingpost truss type           were common years ago in rural areas but are rapidly becoming scarce because of age, fires, floods and ice jams.

4. FINISH AND LETTERING

      I treated the wood stock with a wash of diluted India ink. I also punched nail holes into the           planks using a punching wheel.

5. SCRATCHBUILDING

      The bridge is completely scratchbuild using different sizes of scale lumber and brass wire.