SALT CREEK -- 4 -- TUNNEL 10 TERRAIN

My march up Salt Creek canyon filling in the basic landforms arrived at Tunnel 10.  This tunnel has rock sheds on both ends, with the RR-West face opening out on Noisy Creek Trestle.  Working RR-West from Tunnel 12, I created a rock wall face base on one side with the other side falling off toward the creek.  I will return to this area with rock molds.  My terrain covering the tunnel has a very steep fall-off into the creek forced by the proximity to my Wicopee siding which loops inward--toward the wall and the Tunnel 10 track, pinching the terrain near Tunnel 10.  I will need to apply more rock work to this area, as I wanted to retain the creek down in what became a gorge.

RR-East approach to Tunnel 10.  The gray slope above the track will become a rock face with rock molds applied. Similarly, the steep gray terrain slope on the left forms part of a gorge.  Wicopee siding and main show in the lower left corner, forming a very narrow strip between Wicopee below and Tunnel 10 on the upper line.  The track connects behind the camera via Salt Creek Trestle.

Working with tunnels, I first establish the terrain line along the wall (backdrop).  Next, as with Tunnel 10, I establish any support system in front of (closer to the aisle) for the terrain.  I then find it best to establish the terrain at the portals.  Finally, I fill in the terrain over the rest of the tunnel.  For tunnel 10, I needed to create the gorge with its steep slope and the RR-East approach with a much shallower slope. Geologists will be amused by my terrain shaping, but this is part of the art of model railroading--creating an effect or appearance rather than fully modeling actual terrain.  Consider that as the art of compromise.  It must fit within hard physical boundaries with the railroad taking priority.

Creating the terrain for Tunnel 10.  A terrain profile slab of foam has been attached to the wall (backdrop). A front terrain form (support panel) has been installed in front  of the tunnel.  Slopes for the tunnel portals and rock shed extensions have been installed.  Finally, the ridge terrain is taking shape with panels spanning between the rear (wall) terrain form and the front support.

Once the rough terrain shape was formed with pink foam panels, notable gaps were filled with spray foam insulation.  All of this was then shaped using knives and a Surform ™scraper. A couple of treks through the kitchen section of our local Goodwill store netted some good tools for terrain forming.

Tunnel 10 and RR-East approach terrain formed and spray foam insulation applied to cracks and joints.

Tunnel 10 terrain shell formed and shaped.  I added a knob to the steep panel face forming the tunnel side of the gorge.  This helps break up the expanse.

Finally, I spent three and a half hours mixing and applying Sculptamold to the foam shell.  This session covered the Tunnel 10 terrain and completed the lower section of the Salt Creek canyon leading to Salt Creek Trestle.  As with prior terrain forming, I mix latex house paint in with the Sculptamold so there is a base color for any chips or dings.  It also provides immediate color without the "snow effect" of the basic white Sculptamold.  I used a tan color for earthen areas and a gray for areas representing rocks.

Completed base terrain for Tunnel 10.  The gap below the track and rock shed on the left will become a scenery access hatch.

SALT CREEK -- 3 -- TUNNEL 12 RIDGE

Continuing to fill in the terrain around Salt Creek Canyon, the next major element was the ridge penetrated by Tunnel 12.  On my railroad, this is the first major tunnel RR-West of the Salt Creek Trestle and the first of two located high on the wall opposite Wicopee and the turn-back lobe formed by the trestle.  This is a large ridge, helping to fill the large space created by a track plan with a 42-inch radius turn-back lobe.

The size of the ridge and the depth of the scene demanded access hatches. The ridge is flanked by a pair of formal access hatches.  These eventually will have hatch covers mounted on sliding rails to allow easy access for clearing derailments and maintenance.  As I worked in this area, I also found it desirable to provide additional removable hatch sections that will permit working on the scenery on the top of the ridge and then coming down from the ridge into the creek canyon.  I eventually plan on covering the hatch edges as I work down with final ground cover, but for now, the edges show up as ugly scars in the terrain.

I used the same basic terrain construction for the ridge as the previous efforts for Tunnels 3 and 5.  Basic scenery formers were applied to the wall and at scenery break points.  The intervening terrain was formed from four-inch-wide planks of pink insulating foam.  The difference for this ridge is that it is formed on one permanent section against the wall and two sections on the removable scenery hatches.  

Terrain for the Tunnel 12 ridge has just begun being formed between the tunnel portals and the two permanent access hatches on the right.

The second section of the Tunnel 12 ridge has been formed between the two permanent access hatches.  Spray foam insulation has been applied to gaps between foam planks and to help form rock outcroppings.  Formers for the lowest portion of the ridge are in place on top of the lower scenery hatch.

The terrain has been filled in with pink foam slabs and shaped.

Final base terrain applied for the Tunnel 12 ridge and Salt Creek below it.

A massive effort with Sculptamold ™application covered over the pink foam for most of the area created by the Salt Creek Trestle turn-back lobe.  I try not to leave the terrain in the "pink foam snow storm" appearance for long.  Regular operating sessions plus the up-coming NMRA Pacific Northwest Region Convention in Portland serve as incentive to move this process along.

An OGEUY (Ogden to Eugene manifest freight) drifts down grade out of Tunnel 12 and onto Salt Creek Trestle.  Scenes like this keep me moving ahead on converting my railroad from a "Plywood Pacific" into something more recognizable as the SP in the Cascades.

SALT CREEK -- 2 -- HIGHWAY 58

Joining the railroad along Salt Creek is the Willamette Pass Highway, Oregon Hwy 58.  Salt Creek Trestle spans both the creek and Hwy 58, providing easy access for viewing railroad action on that trestle.  The highway is an important part of the scene.  

One challenge faced by my model scene is that I compressed out of the scene many miles of creek and highway.  While I planned for the highway to pass under the trestle, I needed to have it disappear from the scene.  The prototype Hwy 58 passes through a tunnel further up the pass.  Having my model highway plunge into a tunnel would be a good way to disguise its exit from the overall scene.

I laid out my Hwy 58 on a broad curve that sweeps under the trestle and then curves off to disappear into the tunnel under the roadbed for Wicopee. Viewing from the edge of the layout, this makes for a sweeping left curve.  I laid out the curve on cardboard and cut that to represent the highway--about 25 HO-scale feet wide.  This was then transferred to hardboard and cut out as the initial form of the highway. 

Highway 58 route laid out.  The Salt Creek Trestle towers were removed for scenery work around the piers seen in the upper portion of the photo.

As I worked with the highway scene, I needed to have it rise a bit from Salt Creek Trestle, just as the prototype highway climbs toward the pass. I formed the initial road grade using the insulating foam used for terrain formation.  Some of this needed to be sliced to thinner profile and then smoothed to make a good road grade base.  I then added a subroadbed of hardboard that I could sculpt into the terrain using Sculptamold.  The "final" highway (hardboard) could lay on top of this allowing removal for further highway pavement treatment.

Rough highway grade.

Slicing the insulating foam to the desired thickness.  A belt sander was used to further smooth and shape this road grade.

Once the highway was prepared, I built the tunnel.  I used blocks of three-inch thick insulating foam to form the tunnel.  Laying out the tunnel arch with a pen, I cut out the desired shape using a bandsaw.  I created a cut stone face to the tunnel portal by drawing it onto the foam with a pencil.  The pencil embossed the foam. I painted the tunnel interior gray and then added a thin  mixture of Sculptamold to the portal.  I needed to go over my "stone" embossing so it would show through this thin covering.

Highway 58 tunnel segments joined.  The portal has been embossed using a pencil to form the cut stones used on the prototype Highway 58 tunnel.

Highway 58 tunnel fit into the terrain. Spray insulating foam was used to fill cracks and form rock outcroppings around this area.  Most of the white spray foam seen here was trimmed back before the Sculptamold was applied.  The hardboard highway subroadbed can be seen in the foreground.

Highway 58 tunnel installed within the terrain.

With Highway 58 installed, I can move on to other parts of the Salt Creek scene.