SALT CREEK TRESTLE – 3 – UNDERPINNINGS

Salt Creek Trestle has been a major focus for me over the holiday period.  Prior posts on the trestle can be seen at:

https://espeecascades.blogspot.com/2017/12/salt-creek-trestle-1.html

https://espeecascades.blogspot.com/2018/01/salt-creek-trestle-2towers.html

With the trestle girders in place on the spine and the towers built, it was time to install the trestle into the layout structure.  The critical part of this involved getting the towers to the right height above the scene plywood base plate such that they actually support the trestle girders. 

The first step involved making tower base plates upon which the tower piers and additional height supports were mounted.  As seen in the prior post and repeated below, the plates were roughly 4 x 5-inch pieces of plywood with the tower piers attached.

Salt Creek Trestle towers mounted on their base plates.

I created a master and mold and cast the piers in Ultracal30 ™.  The piers are truncated pyramids using the standard 12:1 batter for SP concrete bridge parts.  My November photo expedition confirmed this shape.

Salt Creek Trestle Tower Pier with travel companion and regular operator Jim M. standing alongside for size reference.  Jim is six feet tall.

Trestle Pier Mold Master.

The piers were mounted to the base plate and additional risers installed where needed to account for shorter leg lengths.  Those shorter leg lengths reflect the sloping terrain.  I will fill in around the piers and cover the risers with scenery material when I work on the scenery for the trestle.  A quick coat of paint representing a concrete color finished the tower plate preparation.

The tower base plates were mounted to pieces of 2 x 4. The 2 x 4 supports were cut close to the overall height needed for each tower mounting.  These were then cut into two pieces along a 45-degree angle to provide height adjustment.  I used 2 x 4 for this to provide lateral support as well as height.  A splice plate was attached to one post piece.  The post and tower assembly was fit into place and the final height secured, first with a C-clamp, second with screws.

Establishing the height for the 2 x 4 support posts to be mounted under the trestle towers.

Trestle tower height adjustment.  Note the up-hill tower legs have filler pads on top to provide for the mountain grade the track and trestle maintain.  I had to use C-clamps, which are relatively balanced, rather than the spring clamps seen to the right.  The spring clamps caused the assembly to tilt over to the side.

Salt Creek Trestle grade check using an electronic level.  The five tower heights were adjusted to maintain a steady grade.

The final piece of the underpinnings for the trestle involved the trestle abutments for the ends of the trestle.  These are cosmetic for my trestle.  I built them from styrene sheet and strip.  They are relatively simple shapes, not even having the usual bridge batter, as seen in my prototype pictures.

Trestle end abutment in place.  The abutment is supported by a block of 2 x 4 and held in place with adhesive caulk.

Mike L. controls a RR-Eastbound over the new Salt Creek Trestle during my January 2018 operating session.  Major railroad elements are coming together to form scenes of the Southern Pacific in the Cascades.