Pilot Assembly


JayWC

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This was a commissioned piece for an organization building a full size working copy of one of the two steam power railroad engines that can be seen in the famous photo of the golden spike being driven at Promontory Point, UT.

Many people inaccurately call the pilot assembly a cow catcher. The purpose was actually to push items off the track...not to catch them.

Please keep in mind, when I started this project, I was in well over my head. I had to push myself, learn and improvise along the way. I am sure there are easier or faster ways to do some of what I did.

I was actually given the wood for this project by the engine builder. It was re-claimed old white oak. The boards were dirty, worm holed and twisted 8/4. After cleaning up the mating surfaces with a belt sander and straight edge, I laminated the two main beams. The first was around 9' long with the section dimensions of 13" x 8.5". That beam is permanently mounted to the engine. There is also a second beam that was around 8" shorter that was 6"x8.5". The lamination process was done on a large steel I-beam that I shimmed to level on my shop floor. I clamped each successive board to the glue up at each step. Per the engine builder's recommendation I used Gorilla Glue. In hindsight I think I should have just used Titebond III. It would have been much easier to clean up and made less foam on the glue-up.

From the glue up, I began the process of hewing the two beams out of the oversized blanks. I used a powered hand plane, belt sander, framing square and string-line to create the two beams. There was no way to run these heavy beams through any of my shop equipment due to weight and size. After making one side flat, I made two more faces parallel to each other and square to the first. The third side fell into place. I made sure to have two good mating faces with parallel tops and bottoms where the two beams joined each other. Once both beams were done, I drilled the 1" diameter holes for the long square head bolts to clamp them together. This was done with a 1.125" brad point bit and a shaft extension. I first made a guide block on the drill press that I clamped on to start out straight. After that the brad point bit tracked nicely through the wood without deviating more than a 1/16" on each hole.

I routed the edges with a large round over bit. I think it was a 1.25" radius round-over. Then the main beam was set aside.

Using the metal frame the builder provided to me, I laminated, planed and cut the pieces to fit. From this point forward, everything was assembled using mortise and tenon with lag or through bolts. I drilled holes to attach the sleepers, risers and secondary beam to prepare for fitting of the staves.

I was amazed by the next part. Making the staves (the individual sloping front pieces) was a very precise operation. When done well; however, it appears very organic in design. It has a nice flow. First I installed the middle stave. This one is a straight piece with a miter on the bottom and tenon on top. Then I moved on to the side staves. I began by cutting the rough shape of each stave, finding the angle of the bottom and top, and adding the length of the tenon to the top. Next I cut the mortise and tenon to fit. I made an adjustable jig to hog out most of the tenon with a router and 3/4" piloted bit. I finished the mortise with chisels. The rough stave then fit into the frame. I marked each side of the stave at the top and bottom where it met the metal frame and top wood beam. Each side is actually a straight line. Those lines are on different planes though. I did a no-no and cut the waste off each stave by twisting the piece as I ran it through the bandsaw. Basically it started on an edge, and at the end of cutting a rifled type of cut, laid flat on the table. The I fired up the powered hand plane and cut the remaining wood down to my lines. A final touch up with the belt sander produced a clean piece. Basically I repeated the process over and over until both sides were done. I found that by being precise, both sides matched identically. The pieces are parallel and symmetrical.

This was a very enjoyable project. It took me 38.5 hours of shop time from start to finish although because I did this on off hours after my work it took a few weeks on the calendar.

The engine builder took ownership of the assembly with the wood in its unfinished state. He had the worm holes (about the size of powder post beetle holes) puttied, primed the piece, painted it red and finally gold-leafed.

I am posting only the finished product photos taken on the day I finished and cleaned up the shop, but do have in progress pics as well if anyone has specific questions.

The photos show how flowing and organic the project is. Those engineers of old knew how to make things functional and beautiful.

I look forward to any comments or questions you have.

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  • 1 month later...

I'd better not show this to my son. He is train obsessed and convinced that I can build anything in my garage shop. For the better part of a year now he has been asking me to build him a train out of wood, with coaches, crossings, passenger cars and tracks no less, that is big enough for him to drive around the neighborhood.

I told him I'd get on that just as soon as I finished the soccer stadium, figure 8 race track for his PowerWheels car, pirate ship and all the other stuff he is just sure I can build for him.

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