The bridge and trestle span 90 feet on a 2 percent grade. The 30 foot radius curve
covers 90 degrees of turn. The bridge is very rigid, there is no detectable deflection
in the bridge even when a person tries to bounce on it. The structure is sturdy enough
to handle heavier equipment. There have been no derailment on the trestle or bridge.
I am very pleased with the results.
While the bridge design is based on actual truss bridges, it is not intended to be to
scale. The bridge has a 15 foot span and is supported by double bents at each end.
This area of the NPCRR is very dry in the summer and very wet in the winter. Water
flows across the meadow and under the bridge during rain storms. The gravel
embankments could have been extended to do the same job but I preferred the look of
the bridge and trestle.
Planning and construction took several months. First the right of way was marked on
the grass using upside down marking paint. Control points were set by locating center
points for the approach curves at each end, then using a string line to mark the curve
centerline. The next step was to mark the tangent between the curves. The first bent
was marked at the point where the curved trestle ends and the straight portion begins.
Working both directions, bents were positioned every five feet. I established the end
points and decided on the length and position of the bridge. Finally, I received design
and right of way approval from the governing authority, my wife.
|This bridge is a focal point on the North Pacific Coast Railroad.
|North Pacific Coast Railroad
|Bridge and Trestle Construction
|This material is provided for personal use only - all rights reserved. 2007
If you attempt a project like this, you are responsible for calculating the load
handling ability of your structure. Failure of a bridge or trestle can result in
injury or death. The author and this website are not responsible for checking
your calculations or workmanship.