Building The Whiteside Trestle
There are several components that were crucial to our success in building the Whiteside Trestle.

The first was the plywood box-temporary bridge-ledger board. It was constructed in the shape of a square-A and spanned the entire 13 foot valley sitting in mortised stop-blocks at each end. Once the number of bents was decided, the length of the box was evenly divided and marked on two adjoining surfaces. These division lines were ‘dropped’ to the valley below using a machinist square initially and later more accurately with a 3-D laser.

The other "star" of this operation was a clamp designed to align and hold each bent in place for final glue-up.

Harold fabricated the clamp which consisted of two aluminum plates in an L-shape with a bar underneath which would tighten down securing the top beam of a bent when it was inserted.

The clamp itself was secured to the box-guide with its right edge aligned with the mark of a bent's location on the layout. Two slots were milled into the main plate to accept the steel pins at the top of each bent.

Holes were drilled in the plywood footers set into the insulation foam and the particular bent was cut to length.

The bent's top beam and its pins were then inserted into the clamp with the bent's feet sitting in the drilled holes. Five-minute epoxy was dropped into the holes while the whole box-guide and attached bent was lifted at one end, pivoting on the opposite end which remained in place in the mortised end-block.

The box-guide was lowered and the bent landed in its forever-home - a happy bent.

Note in the photo on the left (between Charlie's arms) the crib dam which is clamped to its bent temporarily while the epoxy sets. The three bents which sit in the river each have a crib dam at their base.
Charlie sets the last bent on a middle pier below.
The next step was to build the 2 stringers which would each be 13 feet long and sit on the top beam of each bent over the pins. These would be made from a "sandwich" of 3 layers of hardwood strips - two outer layers of long, staggered strips glued-up to a middle layer of strips cut to the length of the space between the pins on each bent.

The box-guide was laid on its side and the "sandwich" was glued-up using the guide's pin location marks.


Horizontal bracing will be added along the ends of the beams on each tier as in the original bridge as well as some side cross-braces.

The primary structure was in place, however, and celebratory toasts ensued.