SHADY CREEK TRESTLE

Construction along my mountain climb has arrived at Shady Creek Trestle (viaduct for the civil engineers).  This is the third and final steel trestle on the line--both prototype and my model.  Prototype photos and information can be found at:

http://spcascades.railfan.net/structuresShadyCreekBridge.html

Shady Creek Trestle has both steel towers and concrete piers in contrast to the all steel tower supports of the other trestles on the line.

My Shady Creek Trestle required cutting in a new aluminum strap spine. My prior trestles (Salt Creek and Noisy Creek) had their aluminum strap spines installed during initial roadbed construction.  During my construction of the mountain grade in 2015, I modified my original plan for this area by placing the bridge/trestle track on an S-curve alignment.  The aluminum strap spine I had at that time had been rolled to a simple curve.  I modified my plan to the S-curve alignment to create a bit more space for Tunnel 8 at the RR-West end of Cruzatte, thereby creating a better visual transition between scenes.  I was careful with the S-curve to include a substantial stretch--more than a foot--of straight track between the reverse curves of the S.  This minimizes coupler alignment issues with long cars and has proven successful over the past three years of operation.  

Original construction "temporary" track for Shady Creek Trestle location.  Note the straight track gauge between the reverse curves.  This gauge is ten inches long with additional straight track beyond it before the track curves right.

Construction for this trestle began with cutting in the new aluminum spine. The original simple curve spine was reworked by my 1.5-inch scale modeler friend, Richard Croll.  The spine was built up from a pair of 1/8 by 3/4-inch aluminum straps, separated by 1/8-inch blocks.  I needed to cut slots in the spline roadbed at each end, insert the new spine and attach it with screws.

End joint for the trestle aluminum spine contained within spline roadbed.

New trestle spine installed.

After removal of the temporary track and spline roadbed and replacement with the new aluminum spine, trestle construction proceeded in the same manner as the two prior trestles:

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

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

https://espeecascades.blogspot.com/2018/01/salt-creek-trestle-3-underpinnings.html

https://espeecascades.blogspot.com/2018/02/salt-creek-trestle-4-walkways-and.html

https://espeecascades.blogspot.com/2018/01/noisy-creek-trestle-1-basic-structure.html

https://espeecascades.blogspot.com/2018/02/noisy-creek-trestle-2-track-deck-and.html

Core components of the trestle are the bridge girders (using Central Valley girders), the steel towers (using Micro Engineering trestle towers), the underpinnings--"concrete" parts including abutments and piers, and the track deck, which includes the walkways and handrails.

Shady Creek has a bit more "concrete" work than the other two trestles.  The foundation for the RR-West steel tower is a complex structure.  One leg (the uphill-RR-West leg) is shorter than the other three.  In addition, the foundation is built as a set of retaining walls, forming a "U" shape.  All of this uses the standard 12:1 batter (vertical slope) of SP concrete work. The retaining walls on the RR-West and uphill sides stair-step down from the height needed for the short leg (uphill in both directions).  

I built the complex shape for this foundation beginning with a bottom plate and top styrene plates.  Interior legs were cut from styrene square tubing.  This is easy to cut and finish to the desired lengths, firmly fixing the desired geometry.  A final check with the basic structure allowed for final height adjustments or shims to be added.  The sides were then built up around this core, including the inside middle section which had angle cuts on both sides and itself was on an angle.  The stair-step horizontal pieces were glued in place and then the end caps.  All of this was sanded to the final shape, removing traces of the glue joints.

Foundation for the RR-West steel tower under construction.  This was a great check on the geometry of the various levels of this foundation piece.

Completed RR-West tower assembly with tower and foundation.  I needed to add 0.060-inch shims to the bottom of each tower leg to raise the tower bottom diagonal struts up off the stair-step foundation.  Such shims are useful and can be seen in real life under bridges.

The other "concrete" pieces--the abutments and the two piers--were more easily built.  The two piers have the same 12:1 batter, so I used a similar construction technique with interior legs made from styrene square tube encased with styrene sheet.

The remainder of the trestle construction followed the same techniques used for the two prior trestles cited in the blog post references listed above.  As I worked through these familiar steps, I found myself just wishing this project to be DONE.  The challenges were met and a standard design developed and applied. It was time to move on.

A final check of the bridge track alignment before building up the walkways and handrails.

Completed Shady Creek Trestle with the first train rolling over it.

WESTFIR DEVELOPED

As I fill in terrain around my railroad, one scene demanded early attention--Westfir.  As seen in previous posts on the bridge at Westfir and Western Lumber, e.g.: https://espeecascades.blogspot.com/2017/10/western-lumber-2.html

This layout corner scene is important to setting the location of my railroad in timber country.  Further, the bridge over the North Fork of the Willamette River leads directly into a tunnel through "THE Oak Ridge" into Oakridge.  A critical scenic transition is needed here.  

Tunnel 22, which pierces the ridge, marks the transition from the Willamette Valley into the Cascades.  It also serves as a major visual and operational block at the RR-East end of the Oakridge Yard.  The tunnel and bridge challenge my operating crews every bit as much as the prototype geography challenged SP crews.  The RR-West face of the tunnel sits almost on top of the RR-East switch at Oakridge. This complicates switching moves at this end of the yard in both model and prototype forms.

During my initial wave of terrain-forming this winter, I built up the contours of the ridge over Tunnel 22.  I did not complete the job, as I continued to struggle with the scenic treatment of the river and the log pond for Western Lumber on the Westfir side of the ridge.  Along the way, I also found my initial plan for the ridge capped it too high, leading to some too-dramatic cliff faces.  I eventually resolved both scenery issues with judicious placement of river dams and a trim to the top of the ridge.

Initial construction of ridge over Tunnel 22.  Note the nearly vertical styrafoam panels above the tunnel portal.  Also note I have not finalized the terrain reaching down to water level.

RR-West side of the ridge over Tunnel 22--the Oakridge side.  Once again, the terrain is too vertical.

The top of the ridge has been cut! 

The river and log pond proved more challenging.  I needed to convey a sense of place, but my model railroad geography was quite different from the prototype geography.  This is where the art of model railroading intervenes.  My scene is something of a mirror image of the actual scene, with the railroad curving the opposite direction.  I also needed to place Western Lumber between the railroad (outside) and the backdrop (inside).  The log pond formed by a dam on the river downstream of the railroad bridge on the prototype needed to be upriver of my modeled bridge.  My solution was to build up both the log pond and the river dam upstream of my railroad bridge and then make the best of it with terrain slopes. 

Once I fixed the permanent location of the dams and the height of the log pond and adjoining river, the rest of the scene came together.  I need to trim a bit of the plywood base seen alongside the backdrop in the photos above.  I also needed to trim a bit more of the plywood base around the log chain up from the pond to make that scene come together.  I chose to use the previously installed hardboard for the log pond and river at their initial heights, adjusting the dam heights accordingly. This will lead to these surfaces defining their respective water surfaces.  The logs in the log pond will need to be trimmed to half logs to represent floating logs on top of what now will be a fairly shallow "water" treatment.  That is a small price to pay for resolving this important scene.

Once the fixed elements were in place, I completed the rough terrain form and then applied Sculptamold.   After my ridgetop trimming and application of Sculptamold, I found I needed to rebuild a bit of the top of the ridge to provide a smoother contour.  This was just fine tuning of the resulting scene. With the deadline of the June 2, layout tour for the NMRA PNR Convention, I worked to flesh out this scene toward a bit more finished appearance. Work remains, but my current sawmill scene matches well to the current level of scenery formation on my railroad.

Revised ridgetop and filled-in rough terrain foam slabs at Westfir. Note the top of the ridge is a bit flat. The ridge was built back up a bit after the first Sculptamold application.

First pass at Sculptmold on the ridge between Westfir and Oakridge. Note the flat spot near the backdrop on the left side of the ridgetop.

Completed Westfir and ridge terrain.  The ridgetop is more rounded.

Western Lumber scene at Westfir coming together.

A final note about Tunnel 22.  This tunnel was bored during the true E.H. Harriman era as the Southern Pacific built up to and into Oakridge.  As such, the tunnel portal and lining conform to the "Harriman Standards" of that period, including the masonry portal and wing walls.  I purchased and stockpiled a set of these portals and wing walls years ago when castings for such were commercially available. Little did I know at the time that the pair of portals and walls I acquired would be exactly what I needed for my eventual dream layout.  Subsequent construction of the Natron Cutoff (Cascade Line) resumed in 1926 following Mr. Harriman's death, Federal Government legal action, and a 1922 US Supreme Court ruling that cleared the way for line construction.  As I noted this past winter as I cast tunnel portals for the rest of my railroad, the rest of my tunnels bear a 1926 construction date and feature a new common design and concrete construction.  My Tunnel 22 properly has the masonry portals, contrasting with the rest of the railroad.

NOISY CREEK TRESTLE AND TUNNEL 9 TERRAIN

Moving up the line and back into a corner in my railroad room, my terrain forming efforts arrived at Noisy Creek Trestle.  The railroad exits Tunnel 10 and its rock shed, crosses the trestle and plunges back into Tunnel 9 which has a rock shed on its face as well.

I began work in the area of the trestle in what has become a standard procedure.  I located and placed terrain support styrofoam planks against the walls to outline the upper reaches of the terrain. I then began adding foam around the fixed elements of the trestle--the end abutments and within the tower pier support platforms.

Initial terrain forming around Noisy Creek Trestle. Back wall terrain styrofoam planks have been placed and the fussy work around the trestle tower support platforms and end abutments has begun.

I needed to build up the foam to the height of the tower platforms. One might recall from my previous posts on trestles that I mounted the base platforms on diagonally cut 2x4 posts to provide for height adjustments.  

https://espeecascades.blogspot.com/2018/01/salt-creek-trestle-3-underpinnings.html

https://espeecascades.blogspot.com/2018/01/noisy-creek-trestle-1-basic-structure.html

https://espeecascades.blogspot.com/2018/02/noisy-creek-trestle-2-track-deck-and.html

The total assemblies were on the order of six inches tall.  The foam needed to come up to the top of the tower platforms and surround them.  From this base, I could build up more foam to the terrain profile needed to encase the tower leg piers or other supports.  I then began filling in the space between the wall terrain profile planks and the trestle tower platforms.

Filling the space between the wall and the trestle.  

As I completed the slope behind the trestle, I also worked on the terrain around the rock sheds on each end and on covering Tunnel 9.  Working on tunnels, I find it best to define first the terrain at the ends of the tunnel around the portals.  I then move on to create the terrain between the portals, covering the tunnel.  Note in all of this, I do the detail work first and then move on to the less critical large terrain sections.

Finally, I built up the terrain at the base of the trestle, beginning to form a water course.  This "drainage" eventually joins up to form Salt Creek on my railroad.  This is a matter of logically joining the modeled drainage into a semblance of what happens in nature.  Once the rough terrain was formed with planks of styrofoam, I filled the gaps with spray foam insulation.  Finally, I formed all of this by carving with knives and my Surform ™scraper.

Rough terrain base formed for Noisy Creek Trestle and Tunnel 9.  

With the terrain base formed, it was time to apply Sculptamold.  With this activity I finally arrived at a task where an extra pair of hands would be a big help.  Calling on John B. for help, I attacked covering the foam with Sculptamold. I originally thought the two access hatches I created on both ends of the trestle would be used to come up from underneath. I certainly used them this way during trestle construction.  I now understand these hatches also need replacement coverings as footpads.  I needed to climb up onto the layout to get access to the back corner of the Noisy Creek scene.  That was a tight spot under the ceiling and above the railroad, but one does what one needs to do.

I am applying Sculptamold to the rough terrain behind Noisy Creek Trestle. This was a very tight spot!  One wears "paint clothes" for this task!

Although I have yet to create and install the scenery plugs for my access hatches on each end of the trestle, the scene with terrain formed and covered is coming together.  I was happy to add a photo of the "completed" scene to my layout design and construction presentation given just a few days later at the NMRA Pacific Northwest Region Convention in Portland.

Completed base terrain for Noisy Creek Trestle.  This view replicates a railfan view from above Tunnel 9.