Southern Pacific Cascade Line: TUNNEL 5 SCENERY BASE

Saturday, March 31, 2018

TUNNEL 5 SCENERY BASE

The major project for me this Spring for my railroad is fleshing out three-dimensional scenery elements. The first such effort dealt with the Summit Tunnel, Tunnel 3. (https://espeecascades.blogspot.com/2018/02/the-purple-pink-mountain-majesties.html ) Continuing downhill, the next tunnel on my railroad is Tunnel 5, including its rock shed on the RR-West end. As with the Summit Tunnel, Tunnel 5 occupies another corner of the alcove space of my main layout room.

I began the scenery shell over Tunnel 5 in much the same fashion as the Summit Tunnel. I attached support plates to the inside of the fascia contour and to the wall. I then spanned the gap with four-inch wide plates of pink insulation foam, cutting these into triangular pieces to work around the corner.

Forming the corner mountain shell for Tunnel 5 and its Rock Shed.

Having turned the corner, I built the rest of the shell for the tunnel and rock shed with more planks of pink insulation foam. Arriving at the portals, I shifted to stacking vertical planks of foam cut to the desired terrain contour. I used this technique to fill in the wall gap between the portals for Tunnels 3 and 5 and then extending further downhill from the RR-East portal of Tunnel 5. The foreground between the track roadbed and the fascia was filled with horizontal foam planks with vertical contour planks used on top of that where needed. I also added foam blocks on top of both the “fan-shape” above the Tunnel 5 Rock Shed and on the ridge over the top of Tunnel 5. This helps break up the flat areas and provided a base for rock outcroppings.

Tunnel 5 rough terrain shell. Note the large foam blocks above the rock shed “fan” on the left and on top of the ridge for the tunnel (area above the vacuum cleaner). Also note the use of both horizontal and vertical foam planks to form the terrain along the wall to the right from the tunnel portal.

I experimented with spray insulation foam to add to the rock outcropping blocks and to suggest more rock outcroppings along the walls. With a new material and application method (spray cans of insulating foam), I had a learning curve. I found the foam came out of the spray nozzle as about a one-inch diameter extrusion that I needed to apply to the desired locations. I snaked this around the rock outcropping areas. I also used the spray foam to fill several gaps between foam planks I had left. I then discovered the spray foam continued to expand for several minutes after the initial application. This left much bigger “snakes” of foam.

As I noted in my discussion of the Summit Tunnel terrain base forming, one becomes a sculptor, removing material that was intentionally (or unintentionally with the spray foam!) “overbuilt.” In the case of the spray foam, I removed a lot of material. In some cases, perhaps 10-15% of the spray foam initially applied remained after carving and then scraping. The pink foam was installed to be close to the desired contour. The spray foam needed to be carved back with a knife to get the rough size and shape desired. In both cases, the final shaping was done with a Stanley Surform ™ scrapper—a very handy tool!

Terrain shell carved and shaped. The tunnel portals and track have blue tape applied for protection, particularly during the spray foam process.

The final step in forming the base scenery shell was the application of Sculptamold ™. Once again, I mixed Sculptamold ™ with paint for color within this covering. In addition to my base tan color, I also used gray paint for areas that will show rock outcroppings. Much like frosting a cake, I lathered this onto the foam base with a spatula. I am not yet confident in my rock carving technique, so I intend adding plaster rock castings to the scenery base for the rock outcroppings. Meanwhile, I have another tunnel and stretch of wall with the scenery base installed.