Tuesday, January 29, 2013

Tori's Trestle - Part 2

In Part 1 I described how my granddaughter, Tori, inspired me to build a trestle on an unfinished part of my Blacklog Valley Railroad.  Using parts from two Campbell Curved Trestle kits, I planned to construct a scale 160 foot pile trestle towering over 40 feet above a rushing mountain stream.  The trestle would be curved to a 22 inch radius. 

Campbell provided materials for hand laid track on wooden ties.  Rather than handlaying all that rail, I opted to use Micro Engineering code 70 flexible bridge track.  The ME track even comes with two lengths of guard rail that fits neatly into molded spikes between the running rails.  In Part 1, I showed how I made a tracing of the tracks that would be replaced by the trestle.

I secured the newsprint tracing to a table and laid the ME bridge track over it, carefully bending the track until it conformed exactly to the tracing.  Then I fastened it down over the tracing with blue painter's tape.

In the above photo, you can see how I am beginning to set one of the two guard rails into position.  I used ACC cement (Superglue) to affix the rails to the styrene ties, weighting them down with lead weights salvaged years ago from an old Linotype machine.

I later discovered that the ACC did not hold the rails very securely, probably because of the wood grain embossed on the ties, so in the end I found that securing the rails with Pliobond contact cement was much more effective.  The finished product looked very realistic.

The guard rails were not just for show.  By glueing them to the ties, the rails fixed the curvature of the track so that it would not be accidently bumped out of alignment with the template underneath.  At this point, I set the track aside, and moved to the next step: Staining the wooden parts for the trestle bents that would support the track.

As I mentioned in Part 1, I had purchased a Campbell trestle kit on eBay that was partially assembled.  Some of the parts had been stained a brownish color.  Others were unstained, as were the parts in the second kit that I purchased later.  I decided to restain the colored wood, along with all the unfinished wooden parts, using a brown Weathering Mix from Hunterline that I had picked up at a train show.  The alcohol and shoe dye solution left the wood a dark brown color resembling wood treated with creosote. 

One of these two bulkheads was previously stained, the other was raw wood.  Can you tell the difference?  (Answer: the one on the right was previously stained.)

With the cross braces stained an appropriate color, it was time to begin assembly of the trestle bents.  The kit instructions included a template on which one could lay out and glue the various components.  Campbell recommends placing waxed paper on the template.  I used a sheet of glass instead, which was easier to see through and clean up afterward. 

In this photo, some of the braces (called "sway bars") have been prestained.  Others were not.  I found that it was quicker to assemble the bents from raw wood, and then dip the entire structure in a weathering bath.  Here an entire bent assembly is ready for the staining process:

The finished product is laid on top of the template for comparison.

The work of assembling the bents was somewhat tedious.  There were 13 of them, not including the bulkheads at either end of the trestle.  The next step would make assembly seem like a breeze.  For the sake of realism, every point where a sway bar crosses a piling needed to have a nut/bolt/washer casting attached.  In Part 3 I will talk about that process, and how I then positioned and attached the completed bents to the bridge track.

Wednesday, January 23, 2013

Tori's Trestle - Part 1

Hanging proudly over the door to my train room is a sign proclaiming: "Pop Pop's Trains".  My grandchildren have been involved in my model railroading since they were little, and all of them are represented in the present layout in some way.   Colby's Cafe is across the street from the Blacklog station.  Clem's Bar and Grill is a popular hangout on Railroad Avenue.  Tucker's name adorns a billboard for the long-gone Tucker automobile.  But only Tori has a trestle named after her!

Tori's trestle was conceived six years ago when my then nine-year-old granddaughter was touring the train room, consisting mostly of 2 inch foam slabs on a wooden grid.  She noticed that the first thing one saw when entering the room was part of the return loop for the standard gauge Blacklog Valley Railroad.   The tracks emerged from a tunnel portal and disappeared into another.  Above the level of standard gauge track was a narrow gauge wye and the quaint mining town of Robertsdale. Tori demanded to know what would go in that short, curved section of track.  I responded that I hadn't really thought about it, and what would she suggest? 

Without hesitation, she reeled off a list of requirements: The track needed to pass over a high, rickety trestle.  Behind the trestle would be a waterfall, crashing into a white water stream that passed under the trestle.  So far, so good.  Then she added, "There needs to be a swamp at the bottom, with fish and an alligator!"  Wow!  An alligator in central Pennsylvania!  That would certain put the place on the map. 

I immediately dubbed the site the location of "Tori's Trestle", and wrote the name on the side of the extruded foam insulation.  And that's as far as it went for the next six years.  Periodically, Tori would ask about the status of "her" trestle, and I would have to admit not much was going on.

The situation might have remained unchanged had I not become involved in the National Model Railroad Association's Achievement Program.  The program awards a series of certificates for mastery of key elements of model railroading: electrical wiring, scenery, car building, and so on.  One of the rewards of participation is that you are encouraged to learn aspects of model railroading that you might never have tried.  I enjoy building structures, and had most of the qualifications for the certificate in that area, except for building a bridge or trestle.  In order to get the structure certificate I would have to build a bridge.  As I pondered what kind of a bridge would fit logically onto the layout, it suddenly dawned on me: This was a great opportunity to finally get to work on Tori's Trestle!

Some years ago, I had purchased a Campbell Scale Models HO Tall Curved Trestle kit (#304-450) on eBay. At the time, I thought I might use it for Tori's Trestle, especially because the kit was advertised as "partially assembled".  Indeed it was, with emphasis on "partially".  In addition, half the unassembled parts were missing and there were no instructions.  A year or two later, I bought a second, identical kit, which came with everything including a detailed set of instructions.  Now I had enough pieces to build a really loooong trestle: Tori's Trestle!

The Campbell curved trestle kit can be built to almost any radius of curvature, from a tight 18 inches all the way up to a three foot radius.  The kit instructions include a page of templates for various radii.  I cut out the template for my 22 inch radius loop.  The instructions also include a template for construction of the trestle bents.  Almost all one needs to construct a trestle of almost any length and curvature are these two templates.

However, prior to beginning construction, I found that I needed a third template -- a tracing of the actual tracks that would be replaced by the new trestle.  After laying a sheet of easel pad paper on top of the tracks, and securing it with tape, I used the edge of a #2 lead pencil to mark the tracks for several inchs beyond both ends of the planned trestle.

The tracing was then moved to a dedicated table where the trestle would be constructed, and secured to the table top.  The entire project would be built directly on the outline of the tracks, ensuring that the finished product would fit exactly into the space designed for it.

In my next post, I will explain how I laid out the ties, rails, guard timbers and stringers for the track, stained and constructed the required trestle bents, and located the bents in the proper position vis-a-vis the track plan.  Before concluding this first chapter, I want to acknowledge the advice and counsel of Dave Trimble and other members of the Yahoo HOn3 Chat Group, without whose help this project might not have been as successful.