The final major element of my
Salt Creek Trestle model consisted of adding walkways and handrails. As noted in my earlier posts on this project,
I chose to model the trestle in its post-1962 appearance with aluminum
paint. About the time of the repaint, SP
shifted to using steel grid walkways and cable handrails. Modeling both of those features presented new
challenges compared to my earlier bridge work with mostly ballasted-deck
bridges and wood handrails. New modeling
approaches were needed.
The prior posts on my Salt
Creek Trestle model can be found at:
Several of my detail photos
from my November photo expedition provided important modeling clues for this
effort. I shot photos from the highway
looking up. This revealed the walkway
support structure and another detail I had not noted previously—a debris shield
over the highway.
Salt Creek Trestle underside
detail. Note the Apex-style (rectangular
slot) walkway, the trestle crossbeam walkway supports, and the cable handrails.
The walkway support crossbeams pass
under the rails forming a continuous beam from side to side. Also note on the right side of the photo the
solid debris shield which covers the span over Highway 58.
In the photo, I noted walkway
crossbeams were spaced three ties apart.
I modeled the crossbeams with Evergreen styrene 0.040 x 0.100-inch
strip. This has the right cross-section
and fits the height of the bridge ties on the Micro Engineering bridge track I
used. Note further that every other
crossbeam has a handrail post.
I chose to use “wood” posts
rather than simulate the steel posts on the prototype bridge. This was a practical matter of choosing
function (holding the cable handrail) over form (thin steel posts). I used Evergreen styrene 0.030 x 0.060-inch
strip for the posts. This provided
adequate post strength when I drilled holes into the post to pass the handrail
wire through. Further, I could glue the
posts to the crossbeams using standard styrene cement and expect it to
hold. Finally, I found I needed to
repair a few posts as I worked with the handrails. Such repairs were easily accomplished using a
fast-acting styrene cement.
I cut the crossbeams to
HO-scale 17-feet pieces. After drilling
a pair of handrail holes in the posts, I glued them to half of the crossbeams. I chose to use only two “cables” for my
handrails rather than the prototype three.
Perhaps I was being lazy, but more importantly, I did not want to weaken
the post still further with yet another hole.
The post assemblies and separate strip material for the other half of
the crossbeams were painted a “tie brown” color using a Rustoleum ™
“Camouflage” rattle can.
I prepared the track by
filing through the tie-web every third tie.
The tie-webs were the thin strip of tie material that connects the tie
strip on alternative sides under Micro Engineering track. I then worked on the underside of the track,
installing crossbeams using canopy cement.
The canopy cement assured a good bond, even with the slippery plastic
used for the tie strip.
Crossbeam installation on
underside of track.
I modeled the highway debris
shield with strips cut from Evergreen 0.010-inch thick styrene sheet. I cut these pieces four HO-scale feet wide
and then cut them into segments to account for the curve my trestle track
uses. The shield plates were painted
prior to installation with the same “tie brown” color. Attachment to the crossbeams was with canopy
glue. Evergreen styrene 0.020 x
0.120-inch strip formed the vertical shield on the outside of the walkways.
Model debris shield.
The walkway grid was cut from
Plano #201 stainless steel Apex grid scratch-builder material. I cut this material into nominal 3.5
HO-scale-feet strips to fit between the ties and the handrail posts. A shout-out to Plano http://www.planomodelproducts.com/ is appropriate here. They have an amazing array of etchings for
model railroaders, mostly for diesel locomotive detailing, but also for various
designs of freight car running boards.
From that, they also found a market for the scratch-builder material
using running board patterns in both stainless steel and brass. My order took less than a week to ship (that
day!) and arrive via USPS priority mail (normal shipping).
Salt Creek Trestle Model with
Apex grid walkways. Barely visible (no
contrast with the ties) are the outside guard timbers outside of the rails, but
inside of the walkways. This photo has
my second attempt at cable railings using strands of copper wire.
The final detail for the
track and walkway structure was the cable handrails. I chose to model my trestle with only two of
the three cables, as each hole in the support posts would weaken them. This proved correct, as I broke several posts
at the lower hole during the cable threading operation.
It took three separate
attempts for me to find an acceptable solution for the cable detail. My first plan was to thread stainless steel 0.010-inch
diameter wire through the holes.
Unfortunately, the supply of Detail Associates wire has dried up, so I
needed to substitute phosphor bronze wire from Tichy, at least for the lower
cable. I had enough of the Detail
Associates stainless steel wire for the top cables. I abandoned this attempt after threading one
lower cable with the bronze Tichy wire.
The shorter segments of wire from Tichy (about 7 inches versus 12 inches
for the Detail Associates wire) meant many more joints between wire
segments. Further, though I could color
the Tichy wire with an aluminum/silver Sharpie, this was a tedious and
incomplete process.
My second attempt at modeling
the cable handrails involved using strands of copper wire from a stranded wire
speaker cable. I split that cable into
its two parts (manufactured as joined, paired wire such as in common extension
cords). I then stripped one of those
wires. The one I stripped was plated
silver, so the color was right to begin with.
This nicked or broke a number of the strands over the more than six-foot
length I worked with, but that still left a large number of intact strands. I
then laboriously unwound individual strands.
This wire was even finer than the Detail Associates or Tichy wire at
0.007 inches. I made an attempt to bulk
this up a bit by twisting two strands together, but this proved very difficult
to thread through the post holes, so I reverted to single strands. Although this produced continuous cables over
the entire length of the trestle (500 HO scale feet long), the copper wire
proved much too soft. I could pull it
taught, but that would deform the track and posts. This left unacceptable bends in the cables in
many spots along the trestle. This can
be seen in the photo above of the model debris shield.
My third attempt at the
cables involved using 0.015-inch steel music wire. This cured the strength and straightness
issue as well as providing the appropriate color. With three-foot pieces of wire, only one joint
was needed for most of the cables. The
outer cables required an additional short segment for the outer cables on the
curved trestle deck. I chose to place the
necessary joints between segments near opposite ends of the trestle. The result with the music wire cables
captures the look I sought.
Final version of the cable
handrails using music wire. I sprayed
flat finish on the completed structure which toned down the reflections from
the walkway grid and handrail.
Electrical feeders are placed close to the rails at both ends of the
trestle. Look closely. A coat of paint camouflages these wires.
The first train over the completed
Salt Creek Trestle. Rodger C. guides the
BRLAT led by SP 9232 over the trestle.
Another view of the BRLAT
crossing Salt Creek Trestle. My vision
for a model of the Southern Pacific in the Cascades is becoming real!
Bill,
ReplyDeleteSimply amazing! Kudos to you for the trial and error attempts at finding the right wire for the project. The finished railing really look great! It's one of those details that would have been obviously missing had you not gone to all of this effort. And the debris guard over the road is a nice touch. Well done!
Tom
You modeling truly gives the feel of the Southern Pacific line over the Cascades. Well done. Keep up the great work.
ReplyDeleteGreat looking trestle, Bill!
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