Thursday, December 28, 2017


Over the past year, I felt an itch to get on with the signature scene for my railroad—Salt Creek Trestle.  That long steel trestle serves as a major inspiration for my layout.  Indeed, a photo taken there in 1973 serves as the background for this blog and another portrait sits along these words as the inspiration photo.  Salt Creek Trestle is one of the most accessible spots on the Cascade Line as it spans both the eponymous creek and Oregon Highway 58, the Willamette Pass Highway. 

SP Extra 8898 East descending in the Cascades, crossing Salt Creek Trestle in September, 1973.

With a two-month break from operating sessions, I could tackle this project which necessarily meant removing a portion of the mainline.  The project breaks down as bridge girders, trestle towers, underpinnings, and walkway.  This first post on the trestle concentrates on the bridge girders.

The three long trestles on my railroad each have an aluminum strap spine to provide strength and geometry control.  The bridge girders are mostly cosmetic, covering that spine.  The spine has been visible for the past two and a half years, supported by temporary risers and overlaid with temporary roadbed. 

The aluminum spines were rolled to the desired radius by my good friend from my California days, Richard Croll.  Richard models in multiple scales, from HO to 7.5-inch gauge live steam.  In that large scale, he has set up a machine shop that supports his work.  This was a case of using large-scale tooling (his rail bending tool) to HO-scale.  The spine was formed from a pair of 1/8 x ¾-inch aluminum straps, rolled and then separated by another 1/8 x ¾-inch spacer.

A RR-East crosses Salt Creek Trestle with a helper set tucked onto the front.  This is an efficient way for helpers to be returned to the base of the climb at Oakridge.

The temporary roadbed was sections of ¼-inch hardboard (my roadbed spline material) cut to the lengths of the future bridge girders.  This included the thirty-feet long sections that span the trestle towers.  I tacked the temporary roadbed pieces on top of the aluminum spine.  Fortunately, when I laid this out during initial construction, I accounted for the scale 30-feet long spans over the towers to be pure rectangles to fit the towers.  This left the longer spans between towers to account for the curve radius, so those sections had ends cut at angles.  This prior work with the temporary roadbed helped guide cutting the permanent model bridge girders to the right length.  The span outside the curve needed to be longer than the inside span.

Temporary roadbed tacked on top of trestle spine for Salt Creek Trestle.  The joints between temporary roadbed sections are just visible, with a scale thirty-feet segment as the second segment in from the left.

I used Central Valley plate girders (210-1903-1) for my bridge girders.  I stockpiled these over the years in anticipation of the need for my trestles.  Salt Creek Trestle has eleven separate girder sections.  With a clean slate, I might use the new Walthers steel trestle system or the ExactRail girders, but with a substantial inventory of the Central Valley parts, that is what I used. 

The girders were cut to length and appropriate end caps applied.  Most of the end caps used Evergreen styrene 1/16-inch angle strip.  I added Archer rivet decals to the angle strips to mimic the rivet detail on the rest of the girders.  The two girders for a trestle span were separated by a piece of 0.125 x 0.188-inch Evergreen styrene strip.  This fit under the top flanges applied to the Central Valley girders.  This produced the correct height when these “saddles” were placed on top of the aluminum spine. 

Trestle bridge girders being assembled.

Trestle girders test fit on top of the aluminum spine.  These are the same spans seen in the earlier photo of the temporary roadbed.

The completed trestle girders were painted aluminum, matching the appearance of Salt Creek Trestle from 1962 onwards.  Although my standard for most railroad structures on my railroad uses 1954 (late steam era) appearance as a guideline, I chose to diverge to a bit more modern for my big trestles.  The aluminum paint is what most operators and visitors will recall for these trestles, particularly the very easily viewed Salt Creek Trestle.  The saddle spacers were painted black, just as the aluminum spine.  This turns both the spine and the spacers invisible once the track is placed on the trestle.

I applied light rust weathering to the base of the girders using Pan Pastels.  This was my first use of Pan Pastels—I like them!  I chose the light rust weathering to match my 1973 photo.  Typical of most railroad bridges, the trestle has not been painted since that original 1962 paint job, so a lot more rust shows in photos today.  I wanted my “time-machine” to represent an earlier time,  so the light rust coating was applied.

The trestle girders were installed using adhesive caulk between the spacer saddles and the aluminum spine.  This fixed them in place, but still allowed for tipping the girder assemblies to level them side-to-side.  That leveling occurred when the trestle towers were placed.  Meanwhile, placing the girders on the spine allowed me to place track back over the trestle, although such placement needed to remain temporary for succeeding construction steps.

Salt Creek Trestle girders installed.

Tuesday, December 19, 2017


Continuing the tunnel and landform preparation, four of my ten tunnels had open gallery rock and snow sheds that extended from their portals.  Tunnel Ten had sheds on both ends.  My third post on tunnel preparation ( showed a prototype photo of part of the shed at the RR-West end of Tunnel Five.  That post also showed my master for the shed portals.  The gallery rock and snow sheds were a signature feature of the Cascade Line.

I fabricated the open gallery side of the sheds using Evergreen styrene strip.  Experimenting for visual effect, I settled on using 5/16-inch square tubing for the posts.  This seemed to give those posts the right “heft.”  That choice settled the rest of the construction.  The top chord was fabricated from ¼-inch square strip with 0.060 x 0.250-inch strip added to the lower chord and 0.125 x 0.250-inch strip laminated to the upper chord for the desired overhang.  The 0.060-inch strip laminated to the ¼-inch square strip for the lower chord provided the width to match the post dimensions.  I assembled the gallery sections on top of copies of my sketch plan.  I added a strip of 0.010 x 0.250-inch to the bottom of the posts to help keep them in alignment and to resist breaking off from the upper chord.

The rest of the shed was fabricated from ¼-inch MDF (medium density fiberboard).  This material provides a smooth surface of the right thickness.  The rear walls were segmented for the two long sheds intended for curved track installation.  Similarly, the roofs were cut into segments with end angles to match the curve. 

Components for the shed at the RR-West end of Tunnel Five.  The plan view began as a track rubbing, helping to define the shed segments.

The walls and roofs were glued together with yellow carpenter glue.  Liquid Nails “Fuze*It” was used for the bonds between dissimilar materials (MDF, styrene, and plaster for the portal).  I learned the hard way to use “Fuze*It” with my plaster castings.  The bonds between plaster segments for the tunnels kept breaking with conventional Liquid Nails for Projects.

Shed Ten East Gallery fit test of assembled gallery.

Tunnel Ten gallery rock and snow sheds in place with the tunnel portals and liners.

Tunnel Nine and RR-East shed.

Shed 7-East.

Tunnel 5 and shed.

With the tunnel portals, liners and, now, shed galleries in place, I am almost ready to begin scenery land-forming.  A critical test for all of the new potential obstructions around the track will be the next operating session in early January.  The railroad is moving along!

Saturday, December 9, 2017


“Boring” along on my tunnel project, I have begun fitting the cast pieces together.  As I cast the final tunnel liner half segments, I can see the light at the end of the proverbial tunnel.  Time to assemble the pieces and test.  Previous posts on creating the parts for my tunnels can be found at:

A number of the castings needed to be trimmed to fit the individual tunnel installation.  Most liners needed to be trimmed top to bottom so the portals can stand vertical. The liners are on the 1.8% mountain grade.  I used a hacksaw for the primary cut, followed by sanding with 60-grit sandpaper.

The second liner trimming has been side-to-side to keep the portal square to the track while allowing the liner to angle somewhat.  This was needed for tunnels on curves.  My HO scale 50 feet long liners (about 7 inches actual) are as long as I care to go for a straight segment around my 42-inch radius.  Combined with the generous tunnel width I built into my portal and liner design (about a scale foot extra clearance around an NMRA gauge), my test of long rolling stock through the tunnel liners was successful.

Test of long freight cars through Tunnel 22 leading into Oakridge.  Autoracks on 89 ft. flat cars have the greatest overhang on curves of any of my rolling stock.  Note the offsets between cars for the pair of cars between liners in the middle.

I assembled the liners, portals and wing walls (when needed) using Liquid Nails for Projects.  The assemblies are just placed on the layout as there are several more steps to go.  A critical test will be to have the portals and liners in place for my regular January operating session. 

Herewith a sampling of the tunnel portal installations:

East face of Tunnel 22 joining Westfir to Oakridge.  The M-Tech resin portals have been installed, but the wing walls await a flattening procedure.  Tunnel 22 was built during the true Harriman era on the SP.  Oakridge served as the end of track for over a dozen years while the SP fought a break-up effort by the US Government.

West portal of Tunnel 21 at the entrance to McCredie Springs.  This is the first of the standard tunnel portals from the 1926 construction of the Natron Cutoff—the Cascade Line.

East portal for Tunnel 20.

Tunnel 12.

Tunnel 9 leading into Cruzatte (to the left).

Tunnel 3, the summit tunnel.

This has been a long project to create the tunnel portals and liners and assemble them.  I still need to paint these pieces, but I want to let the casting plaster cure a bit more.  I also need to paint the track and ballast before installing these tunnel ends more permanently. One more operating session will reveal whether adjustments to tunnels or track are needed.