Big Thunder Creek: Part I ~ Rock Work

This fall I'll be finishing the scenery around Big Thunder Creek, a major scene on the Thunder Mesa section of the railroad.

Howdy, folks!

I've finally returned from my long summer break and I am having a great time getting back to work on the ol' railroad! To start off this season's modeling efforts, I've decided to tackle some long delayed scenes around Big Thunder Creek. This includes the area around Thunder Mesa Mill, an old abandoned mine shaft, and part of the Calico High Line up on top of the mesa. Once completed, These scenes will tie everything together from the Cactus Forest to the Depot area.

Big Thunder Creek serves both to separate and transition between different scenes on the layout.

There's tons of work to be done in this area and it should keep me busy through most of the fall. Aside from the creek itself, there are three bridges to build or complete, the track to paint, ballast and detail, various structures to build, and scenic elements like bushes, trees, cacti and ground cover to add. But first thing's first, and the entire area spotlighted above needs rock-work brought to completion from the bare polystyrene foam that has dominated for too long. Let's get started!

This is how things looked at summer's end after cleaning off the dust and spiderwebs. The foreground bridge was originally planned as a pony truss and a kit from Black Bear Construction Co. was purchased to fill this spot. After getting the kit about halfway finished I decided that it blocked too much of the scene behind it so now the ties will be shortened and the bridge converted to a pile trestle. The shorter bridge behind it will be a scratch-built 20' king post truss. The uppermost bridge on the Calico High Line was craved from Balsa Foam and marks/hides the start of Big Thunder Creek.

A paper-model mock-up of Thunder Mesa Mill has occupied this spot for more than two years, hiding the bare black fomacore behind it that marks the backside of Rainbow Caverns. This area will be addressed as well.

The space was filled in and contoured with 1" pink polystyrene foam. That's an improvement but there's still a long way to go.

Checking site lines, I decided to add a couple of Balsa Foam carved formations to the mesa top. "Window Rock" and "Little Thunder Butte" will add scenic interest and a bit of forced perspective depth to the scene when viewed from certain angles. The rocks were carved using my usual method.

Here the scene is ready for the next step, adding a Sculptamold skin over the polystyrene foam and smoothing the transitions into the carved Balsa Foam.

Sculptamold is a mixture of cellulose and plaster, available through many art and craft suppliers. I've never found anything that I like better for blending things together and sculpting rocky contours. It' lighter than plaster, goes on like thick oatmeal and has a naturally rocky texture when dry. It's a messy process so I remove anything I don't want plastered before getting started. For more on how I contour Sculptamold, click here.

One the Sculptamold was dry, everything was painted with a base coat of latex paint. The color is Glidden "French Mustard."

After the base coat dries, all of the rock work is washed with a thin mixture of black to bring out the texture in the nooks and crannies. The mixture is just a few drops of Carbon Black with a lot of water. Other shades of black or India ink could also be used.

The final painting goes fairly quickly. The rocks are all dry brushed with Raw Sienna acrylics right out of the tube, then Burnt Sienna, Burnt Umber and Unbleached Titanium are worked in sparingly to bring out details and contrast. If things get too dark, I go back and highlight by dry-brushing more Unbleached Titanium. For more details on my rock painting technique, click here.

The cliff face and pad for Thunder Mesa Mill with Window Rock and Little Thunder Butte above.

Soon this rocky chasm will be home to the churning whitewater of Big Thunder Creek.

Okay! The hardest part is always just getting started and I'm happy to have this section of rock work finally complete on the TMMC. Right now I'm finalizing ideas for modeling the many waterfalls and drawing up plans for a rough-hewn king post truss. More to come soon! Adios for now.

Click here for part II