Jumping into Rainbow Caverns

"Now we're going deep into the earth to view the dazzlin' Rainbow Caverns! You'll see giant stalagmites, stalactites 'n colorful falls on every side..." 

- Recorded narration from Disneyland's Mine Train Thru Nature's Wonderland.

Let's Go Spelunking!

After a couple months away from working on the TMMC I figured it was high time to jump back in with both feet and get started on a major project again. Some version of Rainbow Caverns has been integral to the idea of Thunder Mesa ever since I first happened on the idea of freelancing a Disney-esque railroad. Until recently the Caverns have been an empty foam box that trains travel through, but now I aim to remedy that with scenery, animation, sound and lighting effects; creating a colorful underground world seldom seen on a model railroad. I won't try to recreate the Disneyland version scene by scene. Instead I'm going for something more like an homage that captures the feel of the original, along with a little of Knott's Calico Mine Train salted in for good measure.

Geyser Grotto in Rainbow Caverns on the Mine Train Thru Nature's Wonderland, Disneyland USA. © Disney

Cavern scene on the Calico Mine Train, Knott's Berry Farm, USA.

Planning the Caverns 

Rainbow Caverns will be constructed as two separate scenes, each one executed like a small diorama. The first scene will be on the original section of layout almost directly beneath the town of Thunder Mesa. A second, larger scene will be built beneath the Calico Section once track has been laid through that part of the expansion. Since the track and most of the infrastructure is already in place for the first scene, I'll be starting there.

The area for Scene 1 currently has the exterior scenery roughed in with pink foam and the interior painted flat black. The scene will be viewed through cave like openings in the cliff wall and a large hunk of this wall can be removed for access.

Scene 1 of Rainbow Caverns will be viewed through these cave openings in the cliff face.

Here a removable section of scenery has been placed to one side to enable work on the interior of the caverns.

A Backdrop for the Diorama

Scene 1 will be a classic "wet cave" with rushing waterfalls and a large chamber filled with stalagmites and stalactites. In addition to lighting and sound effects, one of the most important elements for making this shadow-box like diorama work will be a convincing backdrop. Since I'll literally be working "inside the box" in rather close quarters, it just makes sense to paint and install this internal backdrop before any more work is done.

I created my Rainbow Caverns backdrop on a 5" x 15" piece of  Strathmore illustration board. Working from the darkest shades to the lightest, I painted the cavern scene with artist's acrylics, using photos from Disneyland, Knott's and real world caverns for reference.

The completed Rainbow Caverns backdrop ready to be installed on its shadow-box diorama. The colors are intentionally over the top, nearly florescent, in order to show up well in the dim cave. They don't call 'em Rainbow Caverns for nothing!

And here is the scene with the backdrop in place. It's a little difficult to photograph without any lighting installed yet so I composited a couple of pictures in Photoshop to illustrate how it looks in person. The next step will be constructing some 3-D cavern scenery to blend with the backdrop. Just in front of the locomotive in this shot will be a ceiling to floor waterfall, animated by fiber optics lights.

Several LEDs will be used to light the interior of the Caverns, including some ultraviolet lights. A hidden speaker will provide the sounds of running and splashing water.

On Down the Line

With the all important backdrop painted I can proceed with building the rest of the scene. Next will come some unusual subterranean rock formations carved from polystyrene foam and painted to blend with the backdrop. Then I'll try and tackle an animated waterfall with twinkling fiber optics. Should be fun!

Thanks for checking in. Adios for now!