MONTIETH ROCK AND TUNNEL 21

My scenery efforts have moved around to my "land down under"--the area between Oakridge and McCredie Springs underneath the upper layer and Cascade Summit.  Specifically, I have covered at long last Tunnel 21, just before McCredie Springs.  I also tackled my significant sculpting exercise--Montieth Rock (also known as "Rooster Rock" but not to be confused with a similar formation in the Columbia River Gorge).  The rock formation over the RR-East end of Tunnel 21 also needed sculpting, as both formations basically are volcanic basalt plugs. Inspiration photos can be found in books, as both rock formations dramatically frame the railroad action below them.  Once again, Joel Ashcroft's excellent SP Cascades website can be consulted:

http://spcascades.railfan.net/  Specifically, the photo section for Pryor to McCredie Springs has a view of the RR-East face of Tunnel 21 and a couple of views of Montieth ("Rooster") Rock:

http://spcascades.railfan.net/photosPryor-McCredie.html

I began terrain construction in this area by establishing a foundation. A scrap piece of hardboard was supported by scrap pieces of plywood to provide a level platform for Styrofoam for the terrain.  For Montieth Rock, I cut slabs of three-inch thick Styrofoam, roughly sixteen inches square. These just fit between the roadbed and the wall.  I created a stack of five primary slabs and then cut two more smaller pieces that would form the top "crown" of the rock formation.  Referring to photos, I drew outer rough outlines for each slab. Given the undercut at lower heights of the rock formation, this often meant keeping track of the extreme width needed for each slab.  I cut to these lines using my bandsaw.

Rough outline for Montieth Rock formation.

Studying photos, I began carving the rough form to shape, slab by slab. My photo study revealed an outcropping on the RR-West side (the side showing in the photo above).  I needed to keep that extension while cutting back the main part of the rock.  I also discovered a second spire behind the main crown.  This showed in photos from the steam era, available from the Oakridge Museum.  I found I worked best by carving the foam in several iterations over the course of several days, refining the cuts as I went.  Lacking photos of the RR-East (geographic west) face of the rock, I used my own judgement based on similar basalt plug formations.  I kept it simple.  Most photos of Montieth Rock are shot from the area of Tunnel 21 as that is both the most accessible to enterprising photographers and provides both track level and elevated perspectives.

Montieth Rock sculpted and shaped--ready for its Sculptamold covering.

Turning to the nearby Tunnel 21, it too has a shear rock face on the RR-East side.  I built up this terrain using slabs of Styrofoam oriented whatever way made the most sense to me.  Along the tunnel portals, these were one-inch thick pieces arranged vertically.  Above the tunnel and its liner, I used more of the three-inch thick slabs.  Above this, was a bit more using both a vertical one-inch piece and a wedge cut from a three-inch slab.

RR-East portal of Tunnel 21 with the rock face above it roughed in. Note the many wires behind and above the Styrofoam formation.  The hardboard channel to their left will form a conduit for additional wires for the signal system.

An important consideration for the corner rounded by Tunnel 21 is its use for routing various wires to Cascade Summit overhead.  This currently includes both the DCC power and a 12 volt DC supply for switch machines.  I anticipate adding a dedicated booster for Cascade Summit, so I needed to add cables for the NCE cab bus, a grounding wire, and a power cord.  I also added a paired wire set for planned LED lighting under the upper deck.  Finally, I provided a separate "conduit" (slab-sided channel) for the cabling needed for the planned CTC and signal system. 

As I built up the terrain forms around the room corner and above Tunnel 21, I realized I should cover those wires and the slab conduit a bit. I cut a fairing from a styrene "For Sale" sign (a good source for a sheet of plastic).  I installed this around the wires and slab conduit using adhesive caulk and flat-headed brads.  We shall see how this survives over time.  Meanwhile, I will need to add a bit of spackle over the brads and then paint the fairing.

Sky fairing above the rock formation for Tunnel 21.

The RR-West side of Tunnel 21 needed a gentler slope, though it also had what will become rock faces.  This side of the tunnel extends to terrain behind McCredie Springs.  I used my standard terrain technique for locations like this where I first place a back panel against the wall/backdrop and a front base with slope.  I then filled in most of the space between these two panels with appropriate length pieces cut from four-inch wide slabs of one-inch thick Styrofoam.  The hillside slopes down to the room corner, behind the rock bunker I will locate here.  The lowest portions of the hill were filled in by Styrofoam strips, cut and sloped as needed.

RR-West end of Tunnel 21.  The hillside and rock above the tunnel blend to a hillside behind McCredie Springs, off to the right.

Gaps between Styrofoam slabs have been filled with spray foam insulation. All of the foam has been carved and shaped and is ready for a Sculptamold covering.

Finally, it was time to cover all of the shaped foam work with Sculptamold. My initial plan was to do this in two stages--the primary rock areas and then the hillsides.  In the end, I used that sequence, but spent a long afternoon doing all of the Sculptamold.  I mixed fairly stiff batches of Sculptamold for the rock work.  The vertical faces and even an undercut on Montieth Rock needed that stiff mixture to adhere to the Styrofoam base.  I usually add my gray base paint to the Sculptamold mix for rock work.  Pictures showed the rock faces to be darker and a bit warmer than my base gray, so i added burnt and raw umber to the gray paint and Sculptamold mix.  I probably needed an even darker paint base, but I at least have the rock faces showing a bit differently than the surrounding terrain. The hillsides gradually blend from my gray base toward my tan base away from the rock formations.

Montieth Rock looking geographic west (RR-East) past Tunnel 21.

Montieth Rock and the RR-East face of Tunnel 21.

RR-West face of Tunnel 21 and hillside extension behind McCredie Springs.

Working in this "land down under," I recognize I need to deal with the lighting for this area soon.  I plan to install LED lighting.  I have been waiting for this technology to mature, which it largely has, but the need for it is very evident today!  Meanwhile, I have fleshed out another signature geological feature for my railroad.