This page is one in a series on the buildout of an N scale model railroad depicting the BNSF Scenic Subdivision in Washington state in the Cascade Mountain Range. You can find the main table of contents for all the articles in the series HERE.

Welcome to Model 160 and we hope you enjoy the project!

 

So I’m now juggling a number of different things for this project at once which gives me a break from doing just one particular thing and allows me some workbench time as well.  Currently construction of the Gaynor Trestle bridge over Nason Creek is on the priority list as we’ll need final model dimensions to plan the benchwork in that area. Gaynor trestle (sometimes called Nason Creek Trestle as well) is located below just eastbound of the Gaynor Tunnel:

 

This 546-foot steel viaduct bridge was constructed in 1949 as part of the Great Northern’s Nason Creek Line Relocation. The relocation was necessary as erosion and rock slides were increasingly becoming an issue. Plus this realignment would help take over 300 feet of mainline out of the existing curved mainline and more importantly provide a straighter run through this area. So to complete the realignment of the mainline, Great Northern needed to build a bridge and a 675 foot long tunnel as well.  Here is a photo looking southeast that shows a train headed east just leaving the Gaynor Tunnel (not visible to the right) and about to cross the new Gaynor Trestle. The old mainline curves in the foreground crossing a curved viaduct:

The project went to the Board of Directors at Great Northern in 1947 and was estimated to cost $896,000 to complete.  The proposal included this paragraph describing why it was necessary to complete this project:

“This location is the weakest link in the main line and should a serious slide occur there is the possibility of a disastrous accident, and the minimum effect would be the taking of the line out of service a long time, assuming the slide occurred when no trains were passing. All precautions have been taken to minimize the danger from falling rocks, including placing steel pins in the rocks. Track watchman is maintained during the night hours when passenger trains are in this section. Nevertheless, frequent rock-falls occur, the most recent one on October 3, when the Seattle fast freight, with three electric locomotives made an emergency stop to avoid striking rock, jack-knifing two empty gondolas and tieing up the line for over 5 hours.”

The bridge used over 630 tons of structural steel built by American Bridge Company. The viaduct  has nine deck girders and spans and three support towers on concrete piers. Construction on the substructure elements of the bridge were complete in fall of 1948, but winter weather meant erection of steel couldn’t take place till April of 1949. A derrick car with 65-foot booms was used to place the beams and girders (seen below):

115 lbs. continuous rail was used for the project back then (since replaced with concrete ties and heavier rail). Great Northern’s own crews did the electrification install in conjunction with the ongoing steel construction. Here is a final photo shortly before the bridge was opened to service in 1949:

Once the new line was opened, heavy fright now had a straight shot through this area and there was a savings of about 5 minutes of time on the 7 mile run from Berne to Merritt.

 

To build this bridge in N scale, I decide that I’d use Micro Engineering viaduct bridge kits as a base for the pieces. From there I would bash it together a bit mating two of the spans together where it crosses over the creek to make the model a little closer to the prototype. So after emptying the boxes of bridge parts on to the desk the first task is cutting all the individual parts off of the sprues using sprue cutters or a razor blade:

This isn’t a difficult process, but it is tedious and you need to sand individual pieces to clean up edges and remove extra plastic flash here and there. So the next step was to tackle the towers that hold the whole thing up. As you can see in this outstanding photo from Matt Donnelly, the towers are built into the side of a mountain and the bottom piers are at multiple different levels:


After looking all over the web for different views I was able to trim the bottom of the towers appropriately and then started to lay the pieces out on the desk to get an idea of overall length and how things will look:

Next I went to work on the girders that make up the spans and needed to start gluing all the individual cross members and pieces:

Once completed I sanded the tops and bottoms to reduce the mold lines and they look like this:

Next step is to glue all of the bottom cross bracing as well:

The prototype has cross ties running across the length of the bridge. I’ve hand cut these individually before on a different bridge project and it is a ton of work. The handrails uprights will be bad enough to deal with:

This time I decided to draw it out and use the laser cutter to make the cross tie pieces as two sections. My first attempt had the tie spacing too far apart:

So I adjusted it and printed a new one. I painted it Roof Brown and laid it on top of the girders and put a piece of bridge track across the top to see how it looks:

And an overall shot:

 

So the next step is to paint the individual bridge pieces, start gluing them up and weather them to match the prototype. I also need to start adding all the handrail uprights on virtually every single cross tie (sigh). But, good news is that I’ve got enough built to be able to get measurements to build the benchwork this bridge will sit on as it will need to dip down to creek level and support the bridge.  More on that in the next installment…

 

 

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Scenic Sub Project Part 3 Scenic Sub Project Part 5