Articles - Building a Crossing
06/07/2009
I have never scratch-built a crossing, so for the small switching layout I am building, I purposely designed one into the track plan to force me to learn to build one. The remainder of this page will show, step-by-step, how I built the crossing. The up-down leg of the crossing is straight, but the left-right leg is on a curve. This makes it interesting and challenging.I have never scratch-built a crossing, so for the small switching layout I am building, I purposely designed one into the track plan to force me to learn to build one. The remainder of this page will show, step-by-step, how I built the crossing. The up-down leg of the crossing is straight, but the left-right leg is on a curve. This makes it interesting and challenging. To start the construction of the crossing, I marked two lines using a piece of Masonite strip so that I could get the flow of the curved track correct. That Masonite allowed me to mark the edge of the ties. I then marked the opposite lines. Next, I simply measured the length of ties needed between these two lines at each tie location, and cut them to length. This photo shows the ties glued in place. I ballast before I start to lay the rail, so the ballasting gets done next.
Building a Crossing
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A crossing is a rather complicated beast, so I decided to make a drawing of each of the rail pieces and their polarity. The red lines represent rails of one polarity and the blue lines represent the other. The gray lines are unpowered pieces of rail that prevent different polarities from making contact, or are used as guard rails. Spaces in between the rails in the upper-left and lower-right corners of the crossing are to be filled with styrene. This prevents the rails from expanding or moving and making contact in the future.
Building a Crossing
For this installation, the curved track is coming off of the bridge, so that is where this project will start. I placed a piece of rail from about the left edge of the bridge. After soldering its feeder wire to it (you can see the wire connected to the DCC bus wire), I spiked the rail down all the way to where the 12-inch ruler is positioned. I used the metal weights to force the desired contour of the rail. I now want to mark off where the rail is to be cut. This is the intersection point between it and the straight leg of the crossing. I used the 12-inch ruler and the track gauge to determine where the left rail of the straight track is to be positioned.
Building a Crossing
After carefully positioning the ruler, I placed a metal weight on it to hold it in place. I then used a fine-point permanent marker to identify on the rail where it is to be cut.
Building a Crossing
The next photo shows the mark I made. It identifies the exact angle at which the cut is to be made.
Building a Crossing
I then used the Dremel tool with a cut-off disc and very carefully cut the rail at the exact angle I drew the mark. This takes a bit of patience and a steady hand, but I did it. From the diagram above, the next piece of rail is the same polarity as the one I just cut, so I cut it and it will be placed up against the first rail. I filed the second piece of rail to match the profile of the side of the first rail at that angle. It's not that difficult to do with a set of different sized files. Then using the ruler and the track gauge, I could position the rail such that it budded up against the first rail and be in its correct position on the ties. The ruler made sure the rail was straight.
Building a Crossing
The next photo shows a close-up. I spiked the rail down at both ends of the rail. This held the rail in place for the next step.
Building a Crossing
I then soldered the two pieces of rail together. This will make a good, reliable connection at this corner. The two pieces of rail will have the same polarity. I cleaned up the solder on the inside of the rail, but the outside, as shown here, is harder to access. I will paint it later on, so it will be less noticeable then.
Building a Crossing
I finished spiking the second rail.
Building a Crossing
After laying the opposite rail of the curved track, I used the same tools to mark the cut point on that rail.
Building a Crossing
I lined up the ruler with the straight track below to mark off where the intersection point will be between the upper curved track and the upper straight track.
Building a Crossing
After cutting off the curved rail, I lined up the ruler with the edge of the straight rail, and placed the upper straight rail against the ruler. This piece of straight rail was already shaped to fit up against the curved upper rail. The metal weights hold it all in alignment so that I can solder the intersection point. Also, to make sure the new piece of rail is vertically level, I placed two tie plates under the rail. This also aligns it with the top of the curved rail.
Building a Crossing
Here's a close-up shot of the joint soldered together.
Building a Crossing
This intersection joins two rails of opposite polarity, so I have to insulate them. I decided to cut the rail mid way between the second and third tie away from the point. This, then, provides two ties to hold the point in place. I cut the gap using the Dremel tool with a cut-off disc. I only did one side at a time, so as to keep the point as stable as possible. I inserted either a piece of 0.030" or 0.040" thick styrene in the gap (depending on which one fit) and applied a drop of superglue to the joint. After the glue set, I used a knife to shape the styrene piece to approximately match the rail.
Building a Crossing
After I cut an insulating gap into the other leg of the point, I have a fully-insulated point. The length of the legs of the point is about the size of one S-scale wheel, so that should not disrupt electricity to engines too badly. The next photo shows the start of the inner curve of the other part of the curved track. I lined up the ruler with the point and placed the next piece of rail.
Building a Crossing
By placing the curved rail, I was able to determine where the two feeder wires are to go. The short section of rail in between the tracks is powered in my solution, so it has to have its own feeder wire. The next photo shows the feeder wires installed and the rail is ready to be placed.
Building a Crossing
After installing the inner rail, I did the same thing with the outer curved rail.
Building a Crossing
This is the state after the outer curved rail has been installed.
Building a Crossing
To complete the upper straight track, the opposite rail can now be installed. I used the rail gages to keep the second rail at the right distance from the first one, but where that rail intersects with the upper curved rail, I had to use the ruler and the track gauge to make sure it remained at the correct spacing (this is shown in the next photo).
Building a Crossing
The next photo shows the straight rail installed and soldered to the curved rail. That joint is of two rails with the same polarity, so there is no need to insulate it.
Building a Crossing
The next step is to install the second rail on the lower portion of the straight track. After trimming its end to the shape of the inner curved rail and soldering its own feeder wire, it was a simple matter of using the track gages to install that rail.
Building a Crossing
Here is a close-up of the joint of this straight rail to the inner curved rail. I fed the solder from inside the corner. After that I used a file to file it smooth with the tops of the rails.
Building a Crossing
I cut the rails two ties away from the point (one at a time) and inserted a piece of styrene to prevent the rails from eventually touching.
Building a Crossing
Next, I cut the curved main line rails so that they provide clearance for the wheels on the straight track.
Building a Crossing
The other pieces of rail to connect the two straight tracks are next. The next photo shows one such rail soldered to its feeder wire and ready to be installed. I power these pieces of rail because they are quite long, which would be too much distance for engines to be unpowered. These pieces were cut to roughly fit within their space. Some additional trimming will need to be done later.
Building a Crossing
I used a ruler to determine where these pieces of rail are to be placed. I marked the location of where the feeder wire is to be soldered to the rail on the top of the rail. I also put a mark near the end of the rail to indicate the side of the rail that is pointing up (in the photo's direction). As I remove the rail, I make a mental note of where the awl should go to prepare the hole to be drilled with the drill. I have found that these short pieces of rail are actually somewhat difficult to install correctly when trying to balance making sure the rail is in line with the main rails and placing the tie plate and spiking at the same time. I realized that one drop of superglue placed near the center of the rail is very helpful in keeping the rail in position. Even if a short piece of rail installs easily, I like to place a drop of superglue somewhere in the center of the rail to assure that it keeps its place.
Building a Crossing
The basic crossing is now built. I use my test car to check the clearance of the rails I just installed. I do that by pushing the wheels all the way to one side and then again all the way to the other side of the track. I used a permanent marker to mark off of each end of the rails how much needs to be trimmed. This photo shows that the rail on the right side near the wheel needs some trimming.
Building a Crossing
After using the Dremel tool to cut the rails so they clear the wheels (remember these rails have power, so it is easy to trigger a short), I used my engine to actually run on each section of track through the crossing. The next photo shows the first successful test run on the very short straight leg through the crossing. The box car is on the curved main line leg of the crossing.
Building a Crossing
Since the crossing appears to work fine, it is now time to start working on the guide rails. There are a lot of them. These are all unpowered. The next photo shows the first one installed on the curved track. A drop of superglue makes sure they don't move.
Building a Crossing
The next photo shows the entry ways for each of the legs protected by guard rails. They are relatively easy to install because they don't require wiring. I only used as many tie plates as were necessary. The tie plates typically had to be cut in half for them to fit snug up against the existing tie plates. I used the regular code 83 rails for the guard rails (for bridges I use code 70). The curved guard rails were slightly bend by hand before installation. The ends of each guard rail receive a quick bend from a pair of needle-nose pliers.
Building a Crossing
The final construction step was to cut, shape, and install the inner guard rails. These require a bit more care, because they must not interfere with the wheels from either direction. Also, they must not touch each other so as to avoid any short circuits. Again, a drop of superglue aids in the installation process.
Building a Crossing
And here is the final photo for this article. I had to tweak one of the inner guard rails to clear the wheels. I then used Floquil Rail Brown to paint all the visible tie plates, spikes, sides of styrene gaps, and the tops of the guard rails. The last step was to just touch the tops of the styrene gaps with Polly Scale Flat Aluminum paint, which makes it blend in with the polished tops of the rails. That worked out well, because, unless you know where to look, you cannot find the styrene gaps in this close-up photo. This completes this project. It was my first scratch-built crossing in any scale. I made sure to allow myself plenty of time to construct it. In calendar time it took me about 5 weeks. However, we were remodeling our house during that time, and I hurt my lower back for about two weeks doing that remodeling which meant that I couldn't bend over the layout for more than a few minutes at a time. Nonetheless, it is a time-consuming project, but I am very pleased with the result.
Building a Crossing