Tuesday, 4 June 2013

Frederick's Mill Bridge

I had known for a long time that covered bridges had been in use in Central Europe since the Late Middle Ages.  Then I learned that these bridges were to be found in the United States, too.

Fallasburg Covered Bridge
(Fallasburg Park, Lowell, Michigan)
Covered bridges are of a timber-truss construction with a roof and sidings, creating an almost complete enclosure. The purpose of this was to protect the wooden construction from the weather. Another reason for building covered bridges was that horses shy from foaming white water, and they could be more easily driven across an enclosed bridge whose entrance looked like a barn door.
I was enthusiastic and wanted to build one for our war-gaming scenarios. After I had finished my model I found out that the first of these bridges was built at Swanzey, New Hampshire, in 1789. Too late. But I enjoyed building the thing.
Anyhow, it could be used for later periods. However, I have restricted myself to the AWI. Still I will document it here for others to make use of the description.
I started with the ramps, using two wooden wedges, some plywood and bits of spare wooden ledges. The rough stone structure for the embankment are just left over bits from previous attempts of model making.
 Into the ledges I drilled holes into which the plugs below the bridge case will fit.
 The case itself was built of thin plywood. Onto the outer walls I glued some stripes of wood from old French cheese boxes. The same wood was used on the interior of the walls to indicate the construction of the king post truss.
This simple traditional truss type dates back to the Middle Ages. It was also used in roof building.
It consists of the tie beam, two diagonal rafters, and the central king post. It allows a span length of 20-60 feet.
The roof was made of two pieces of plywood with two supporting angles of wood.

The outside got stripes of the before mentioned cheese box wood to create the impression of a boarded roof. I could also have made shingles instead. (I will describe that in a later post.) The gables also got their cheese box boards.
This is how the finished construction looked. The final finish is accomplished with moulding plaster, sand, paint, railway modeller's grass and some bits of gravel.
Here it spans Hard Rain Creek, which I had made before (cf. previous posts).

A shame that Frederick's Mill Bridge can not be used in AWI wargaming (unless you surmise that it was the first covered bridge in North America nobody knew about until now).

1 comment:

Chris Stoesen said...

This is really nice. Thanks for sharing. Lots of those covered bridges were up north. They are much rarer in the South.