Curved Pile Trestle

As part of the track-work, I've planned on a trestle over a small creek as a scenic element connecting  Willow Junction to Willow Springs. The plan is to scratch build a curved wooden pile trestle, somewhat similar to one I visited along a Burlington Northern branch line in Washington. While the prototype is not curved, both it and my model have ballasted decks and six pile bents.

I drew up a working drawing of the deck based on a 24" radius section of track as well as a more finished drawing of a bent to use as templates. I planned approximately 12 foot spans between the bents. The pile and bent caps are 16 inch scale stock (3/16" dowels and strip wood) and the caps are 16 scale feet in length. I chose to use a continuous butt pattern for the stringers made from 8" X 16" stock (3/32" X 3/16"). For the decking I am using 3" X 8" stock.

To start construction I stained the stringer stock and some of the decking (pre-cut to 16 foot length) with my Prego jar mix of 70% alcohol, India ink, and raw umber acrylic paint. I set up the working drawing as a template by taping it to a plate glass surface and then taping wax paper over the drawing. I then taped deck planks in place where the bent caps will be located. Then, working upside down, I proceed to glue the stringers in place with Aleene's Tacky Glue. To provide the curvature, the straight stringers varied in length between the bents; some were 12' while others varied between 11 1/2' and 12 1/2' whether they were on the outside or inside of the curve.

While underway with glueing the stringers in place I decided to just use double stringers under the rail and two, rather than three, stringers outside of the doubled stringers under the rails. The prototype, the Milwaukee Road's S-turn trestle in Tacoma, on which I based my bent drawing is a main line, and I am constructing a branch line. More practically, I felt that the underside would be too crowded with stringers if I followed my original plan. Another practical, rather than prototypical choice, was to use several longer stringers to help to tie the whole structure together. At this point I am focusing on constructing a practical model, and hence enabling track-work completion, rather than prototype sincerity. While I am trying to push my quality of modeling with this layout, I am not building this trestle to enter a contest, but rather to complete the track-work and as part of a future scenic feature.