This is the mockup bent that I used to verify the lengths of the bolts that would be
needed. It also allowed me to better visualize proportions and check for
interference between fasteners. One change that I made was to use standard treated
2x4s for the outside stringers and rotate the 3x4s stringers to match. Using standard
dimensional lumber saves lots of money. While the bridge and trestle are not
“scale” , they have the right “look”, are functional and safe. Because the tallest
bent is about 24 inches, I was able to use a standard 4 foot bottom length on all
bents. Taller bents should have a longer base to provide more side to side stability.
If you are not sure how long to make the base, build a mockup of your tallest bent
from 2x4s. All of the others can be measured from it. Taller bents also require
diagonal bracing. Lag bolts were used to attach the bent posts to the top and base.
The top bolt heads are exposed but the bottom heads and washers are counter sunk
into the underside of the base. This is not how a “real” railroad bent is built but it
simplifies construction . Each bent was custom built for the required height. Thus,
the height of the concrete footing was not important, only that it be properly located
on the centerline and above ground level to keep the wood dry.
The end walls were built last in order to match their height to the trestle. The 2%
grade of the trestle was extended out onto each approach then transitioned to a new
grade. In order to maintain good trackwork and prevent derailments, I avoided
sudden grade changes on the trestle and at both ends.
|Trestle bent construction:
|North Pacific Coast Railroad
|Bridge and Trestle Construction
|Click on photo to enlarge.
|This material is provided for personal use only - all rights reserved. 2007