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.

Willow Springs Under Way -- Track Laying Started

Willow Springs side of the layout, with track-work started.

I have started the track-work on the Willow Springs side of the layout, focusing on the mainline and the siding. In addition to positioning several of the mainline turnouts, cutting the track between them, and dropping feeders and frog jumpers for this first section, I went ahead and prepped all the other turnouts. I explained the step-by-step process for hidden feeders on this earlier post, and the process for prepping the turnouts is explained in this video by Luke Towan on Youtube. On this side I will be using slow motion turnout motors. A few years ago, on the layout of one of my Seattle modular friends, we witnessed that the Peco switch rod springs need to be removed when doing this; somehow, with the switch rod spring in place, the timing is off between the switch throwing and polarity of the frog changing which led to shorts.

Underside of Peco Electrofrog turnout with frog isolated (1),
point and stock rails soldered (2), and feeder wire soldered to
frog (4).

Having prepped the Peco Electrofrog turnouts for DCC friendliness on the rest of the layout and made the decision to skip the point rail jumper step, the process goes fairly quickly now:

1. Snip jumper wires connecting center rails to the frog
2. Solder point rails to stock rails
3. Remove the Peco switch rod spring (since I will be using Tortoise switch machines)
4. Solder green feeder wire to underside of frog
5. Check continuity with multi-meter
6. Trim off ties for rail for rail joiners
7. Drill out holes for track nails at the underside dimples

While I had been planning on waiting on constructing the curved trestle bridge, I have decided to start on it as part of the  track-work for this side of the layout. That will have to be a different post.

Willow Springs Under Way -- First Steps

Willow Springs ready for track!

After clearing off the clutter that had accumulated on the Willow Springs side of the layout, I finally prepped for track laying. A how-to description of the details of the process is on an earlier post. Basically, I followed a four step process:

1. cut slots in the cork and drill holes for the switch machine actuating wires
2. cut, sand, and glue on switch stand pads
3. sand the cork bevels
4. paint the cork with a color similar to the ballast.

Because installing a control panel for the Tortoise switch machines and a UTP for the NCE throttle will be needed for checking the wiring, I installed a four foot section of fascia now, rather than after the scenery is started. After cutting, installing, and painting the fascia section, I ran the cab bus wire from the initial UTP , repainted the metal panel, and cut a 1" X 2 1/4" hole in the fascia  to mount the UTP. I also installed two dowels as a throttle holder.