Three bridges now span the rocky chasm of Big Thunder Creek. It looks like a clear, sunny morning in Thunder Mesa country but a storm could boil up in the afternoon and send a flash flood cascading through that dry creek bed. Time will tell...
This past week saw a lot of progress on the layout with the completion of three railroad bridges across Big Thunder Creek. Up on the Calico High Line, a small stone arch crosses the creek where it's narrow at the source, while farther down, a rustic 20' king post truss does the job on the mill spur. Near the front of the layout, a 48' wooden trestle on the main line spans the wide, clear pools below.
Follow along with the photos to see how each of these bridges was constructed and installed.
The Stone Arch
The King Post Truss
The deck, trusses and abutments for this bridge were assembled separately at the workbench before everything was put together directly beneath the existing rails on the layout. This photo shows the simple foamcore jigs that were used to assemble the deck and trusses. Kappler 10' suger pine bridge ties were used above 12 scale inch (1/4") diameter dowels to build the deck. All wood was scribed with a razor saw to simulate age and grain before being stained with a mixture of Kiwi black shoe dye thinned with 70% isopropyl alcohol. My method for creating this stain is to simply empty nearly all of the dye out of the Kiwi bottle and then refill it with alcohol, replace the foam applicator top, shake well and it's good to go.
A pair of wooden retaining wall bridge abutments were also built at the workbench, again using Kappler ties, NBWs and 1/4" diameter dowels.
Installing the abutments beneath the bridge was a little harder than I thought it might be. But after a little cutting, fitting, re-sculpting and cussing, both abutments were cemented into place and the scenery blended in around them.
The 48' Trestle
The Big Thunder Creek trestle started life as a Hermosa Creek Truss kit from Goldline Products and for quite a long time I had intended to build it as designed. In fact, there are many photos of the bridge in various stages of completion in older posts on this site. However, once the real planning for scenes around Big Thunder Creek began it became apparent that the bridge as built would be a little too overpowering. My solution was to remove the trusses and modify the bridge deck into a low slung trestle.
Since this trestle sits in water, stone footings were carved from Balsa Foam. Here a hard 5H pencil is used to carve the mortar lines between stones.
The carved Balsa Foam footings and abutments were first painted with a sealing coat of Buff Titanium acrylic paint. Here a stone retaining wall is also being painted.
Once the base coat was dry, Raw Sienna was dry-brushed on to the faces of the stones.
Individual stones were then picked out with earthy, contrasting colors like grey, Burnt Umber and Burnt Sienna.
A completed trestle bent ready for installation. Each bent was detailed with 24 nut/but/washer castings and weathered with colored chalks.
Oops! It turned out that one of the trestle bents would stand right on top of a large boulder already sculpted into the creek bed. A portion of the scenery was cut away so that the bent's stone footing could be blended into the rock work.
Here's a nifty trick I learned for mixing up small batches of plaster or, in this case, Sculptamold. Pour some into a ziplock bag, add a little water, seal, then squish vigorously until well mixed.
When ready, snip off one small corner and squeeze out like a pastry tube. This works great for hard to reach spots where you don't want to mess up existing scenery or details.
Here both bents have been installed and fresh Sculptamold worked in and blended around the left abutment. The deck is not attached at this point, just floating on the bents so that it can be removed for detailing of the creek bed.
The big boulder has been repainted to match and blend with the existing scenery and real rocks and dirt added to the creek bed.
The creek bed stones were collected from real creek beds in Sedona, AZ and near Silverton, CO. The rocks and dirt were cemented in place with matte medium and white glue diluted 1:1 with water. The fire barrels are painted castings from Rusty Rails.
Here's a view from below Big Thunder trestle. From here I'll continue to detail the creek bed, adding more rocks, junk and some plants before pouring the Envirotex resin "water."
More to Come
Looking at our plan shows there's still much to be done before this area of the layout is finished.
That should just about wrap it up for this week. I hope everyone is enjoying this build and that my explanations are clear. As always, any questions or comments are most welcome! If all goes according to plan, the next week or two should see the addition of cascading waterfalls and crystal clear pools to this scene. Thanks for coming along. Adios for now!
Click here for part III