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.
