I have decided to go with the full length seven-span Etowah River bridge as discussed in the previous update. With the bridge length determined, I had to add support to the roadbed at the north end of the structure. Eventually, the spline roadbed will be cut away and replaced with a 42" length of aluminum channel. The deck girder bridge will then be built in place around the channel and cast plaster piers will be added below.
» Photos
This "before" photo shows the original roadbed support before the bridge length was determined:
This "after" photo shows the additional benchwork constructed, including the riser that supports the roadbed at the north end of the bridge:
The additional benchwork will also support the 1/4" plywood that will make up the river bottom.
While working on the Etowah River scene, I realized some additional benchwork needs to be added around the bridge before track can be installed. Before adding the extra support, however, I needed a way to see exactly where it has to go. To do this, I created some full-size mockups of the bridge scene. The actual bridge is comprised of seven deck girder bridge sections supported by concrete piers. I will eventually be using Micro Engineering 80' ballasted deck bridges supported by cast plaster or cement piers. The following two photos show the mockups I did. The first photo shows the complete non-compressed bridge (seven sections), while the second photo shows a compressed version of the scene with only six sections (one section over the river removed):
I wanted to try out the compressed version because I believed the full size bridge would be too big. Also, six 80' deck bridge sections comes out to an even 36" in N-scale, which means I could use one 3-foot length of aluminum U-channel to be the supporting backbone of the bridge. However, when looking at the two photos the river just seems too narrow in the compressed version. I am also considering using a compressed bridge with the full-size river; in this case, the road would be eliminated. This option is probably not going to be selected because that road is one of my first ever railfanning locations and is a significant reason why I chose to model this area in the first place.
Whatever option I choose, the mockups are a quick way to visualize a completed scene without too much effort (time or money).
A significant milestone was reached on the CSX Dixie Line this week when the final mainline roadbed was installed on the lower level of the layout. There is now continuous spline roadbed from Emerson, GA at the south end of the lower level all the way to the helix at Tilton, GA at the north end of the lower level. This clears the way to finish designing and intslling roadbed for the remaining sidings and industry tracks on the lower level.
» Photos
Looking north from the dropdown gate (far right) to the Etowah River bridge:
Etowah River bridge:
Looking south from over Calhoun, GA to the Etowah River bridge (distance):
Looking south over the entire Calhoun, GA scene:
Looking north over the entire Calhoun, GA scene:
Looking south over the Tilton, GA scene towards the end of the aisle. The north end of the Resaca passing siding is in the foreground, while the siding itself curves around and ends (for now) before reaching Calhoun:
Looking north over the Tilton, GA scene towards the Helix. The Etowah River bridge can be seen in the distance beyond the helix:
My current project is to get all of the the lower level track installed. Trackwork has been in place for almost two years on the Emerson, GA scene, which is the southern most scene on the layout. The following photos show all of the new spline roadbed that I have been working on moving north from Emerson.
» Photos
The first scene north of Emerson is Etowah River. In this photo, you can see the completed spline roadbed along the long curve connecting the dropdown gate across the doorway to the train room (far right) with the Etowah River bridge (far left):
Here is a straight on view of the bridge. This will be a five span deck girder bridge when completed:
North of the Etowah River is Calhoun, GA. I have not yet finalized the design in this scene; you can see in the photos where I have risers temporarily clamped in place so I can move a spline around to experiment with different track alignments. This view looks south with the Etowah River bridge in the distance:
Looking north at the same scene with the temporary track alignment:
Just to the north of Calhoun is Tilton, GA. This is the final scene on the lower level before the track disappears into the helix on its way to Chattanooga, TN. Spline roadbed construction is well under way in this scene:
Looking north at Tilton toward the helix you can see the newly completed spline roadbed in the foreground leading to the double track helix. The completed track connects the helix to Emerson; you can also see the new spline roadbed at Etowah River in the distance:
I have started work on the bridge where the CSX W&A Subdivision crosses over I-75 in Emerson, GA. I will be building this bridge in place; in other words, the bridge will be built around the existing spline roadbed. The only work completed so far is the removal of the scenery base where the bridge abutments will be installed:
Below, I have included a few pictures of the prototype structure courtesy of Google Maps and Bing Maps. The scene on the layout will be simplified compared to the prototype scene in that there will be no off ramps modeled. Instead, there will be two three-lane interstate roadways and three bridge piers.
Looking northbound from the on-ramp from Old Allatoona Road to I-75 northbound:
Looking southbound from the off-ramp from I-75 southbound to Old Allatoona Road:
To spice up the scenery and add operational realism along the southern end of the layout, I added a working grade crossing where Allatoona Road crosses the tracks at milepost WA 39.6 on the CSX W&A subdivision. As the above video shows, the grade crossing functions just as it does on the prototype: as a train approaches, the lights begin flashing and the gates slowly lower across the roadway. After the train clears, the gates slowly raise and the lights go dark. The process repeats itself every time a northbound or southbound train passes through the scene, keeping the imaginary N-scale inhabitants out of harms way.
The signals used in this project are NJ International #2164. These signals are almost an exact match for the ones used at the real crossing and feature large modern "bug eye" flashers in both directions, crossbucks, and moving bar-arm gates with red stripes. The signal flashers on the signal upright are LEDs pre-wired with dropping resistors; however, the lights on the gates are molded on and do not operate. These signals, which are molded brass, come packaged as a pair and are super nice models. Plus, at about $30 they are also a great value.
» Flashers
The flashers are driven by a Digitrax DS-64 quad stationary decoder. The DS-64 is commonly used to operate turnout motors, but it has a nifty feature that allows the outputs to alternate at a rate that is ideal for crossing flashers. The DS-64 can also be connected to the Digitrax Loconet, which means it can operate in conjunction with Digitrax block detection so the signals will activate when a train occupies the crossing.
I strongly recommend testing the flashers before installing the signals on the layout since it will be much more difficult to replace a set of defective signals later on. To do this, configure one set of outputs on the DS-64 to alternate/flash when activated (refer to your Digitrax instructions for the steps necessary to do this).
Connect the signals to the DS-64 as indicated in the Digitrax instructions. Using your throttle, open and close the switch address for the appropriate set of outputs on the DS-64. The lights should flash and then go off as you open and close the switch. In this photo, you can see one of the signals being tested with the DS-64:
After mounting the signals on the layout, simply connect the wires to the DS-64 below the layout just as you did when you tested the flashers before installation. When wiring the signals, be sure that both signals flash with each other and not against each other. In other words, when approaching the crossing in a vehicle on the road, both flashers should be flashing in unison: the right flasher should be lit, then the left, and so on. To see this in action, watch the video above and pay close attention to the flashing pattern of both signals as the gates are lowering. If your flashers are not doing this, simply reverse the connection to the DS-64 for one of the signals.
» Signals
As packaged, the gates have a short actuating wire attached to them. You can see these wires in the photo above where the flashers are being tested with the DS-64. I needed a much longer actuation wire, so I replaced the factory wires with some longer handmade ones. I removed the factory installed wires with a small pair of clippers. WARNING: These signals are very delicate, so use care when using the clippers to removing the actuating wires.
Drill a pair of holes at each signal location: a large hole for the base of the signal and a smaller hole for the actuating wire attached to the gate. To locate the smaller hole, I placed the signal in the larger hole and marked a spot below where the actuating wire attaches to the gate:
Mount the signals in the larger hole using your glue of choice; I used white glue. Be sure to use care and not get any glue on or around the moving parts of the signals.
With the signals mounted, I went ahead and installed the new actuating wires for the gates. To create the actuating wires, I cut a piece of .025 steel wire to about 12" in length. Don't worry about the exact length, you just want enough so that it reaches the Tortoise actuators that will be mounted below the layout. I made a small 90 degree bend in one end using a pair of needle nose pliers:
To install the actuator wire, feed the straight end down through the hole in the layout from above and carefully slip the bent end through the hole in the end of the gate:
With the actuator wire attached to the hole in the gate, it is now basically hanging down through the layout down below the benchwork. You should be able to reach under the layout and move the actuator wire up and down to make sure the gates lower and raise as they should.
» Gates
By far the most complex and difficult phase of the signal installation is getting the crossing gates to actually work along with the flashers. In fact, the installation of the gate mechanism was probably the most tedious and frustrating time I have ever experienced on the layout. There were several times I considered replacing the signals with ones that did not have crossing gates. However, patience eventually prevailed and I can now say that the outcome was well worth the effort. Watching the gates lower and raise each time a train passes really brings the whole scene to life.
There are a few components that you need to buy to make the crossing gate magic work:
(1) Circuitron 800-8100 Remote Signal Activator (RSA)
(1) Circuitron 800-8101 Extra cable & actuator for RSA
The best advice I can give for working with the RSA is to read the instructions from beginning to end. Then read them again. And again, and again, and again. The first time you will be saying "What the...?" but after a while something will click and you will realize the RSA is a brilliant little piece of hardware.
Basically, the Tortoise is attached to a slider on the base of the RSA which in turn is attached a pair of cables that fan out to a pair of remote pivots mounted below the crossing gates on the layout. These remote pivots are connected to the actuator wires that we previously attached to our crossing gates. When the Tortoise moves, the slider moves back-and-forth, causing the cables to extend and retract, which makes the pivots rotate, which cause the actuating wires to lower and raise the crossing gates. Magic.
To begin, select a location under the layout where the RSA will be mounted. You want to pick a location out of the way from the crossing gates as to not interfere with the mounting location of the pivots, but close enough so the cables from the RSA to the pivots will not need to be excessively long. The cables are flexible so they can curve, but don't make the curves too tight or the cables will bind when operated. Consult the RSA instructions for the specific limitations of the cables. Be sure to allow enough room to accommodate the Tortoise motor.
Mount the RSA below the layout according to the RSA instructions.
Mount the pivots below the crossing gates according to the RSA instructions. The actuating wires hanging down from the gates will determine where the pivots must go.
Connect the cables between the RSA and the pivots according to the RSA instructions.
Clip the actuating wires (hanging from the crossing gates) to an appropriate length and attach to the pivots according to the RSA instructions.
Attach the Tortoise switch motor to the RSA according to the RSA instructions.
Wire the Tortoise to one of the sets of outputs on the DS-64. Consult the Digitrax instructions for the specifics of this step.
Using the switch address of the DS-64 outputs, use your throttle to operate the Tortoise switch motor. The entire apparatus should function as described above.
The pivots have adjustment screws that allow you to control their range of motion. If the crossing gates do not raise or lower to their correct positions, play with the adjustment screws until the gates end up in their desired positions.
The following photos show the overall Circuitron RSA installation, looking up from below the layout. In the first photo, notice how a 1x3 crossmember has been added to mount the RSA base and a 1x2 crossmember has been added to mount pivot #1:
It has been over two years since any trackwork has taken place on the CSX Dixie Line, but that changed over the weekend as work started to extend the roadbed through the new Etowah River scene. The CSX W&A Subdivision crosses the Etowah River just to the north of Emerson, GA, and this prototypical arrangement will be represented in the same fashion on the layout. Over the next few weeks I hope to have all of the lower level roadbed in place so I can extend the mainline beyond its current terminus just north of Emerson.
» Photos
This photo shows how the spline roadbed is joined to the dropdown gate by inserting a short "key" section of spline into a slot cut in the deck of the gate. You can clearly see the northernmost extent of the mainline where it ends on the gate. The first spline to be attached to the "key" spline can be seen against the backdrop:
The first spline has been glued to the "key" spline and clamped in place:
Somehow, a few of my risers were a full 1/4" too low. This problem was corrected by gluing some small sections of 1/4" stripwood to the tops of the risers. The nail is centered on the riser and provides a surface for clamping the first spline in position:
The second spline has been glued and clamped in place. You can see the dropdown gate at far right and the future location of the Etowah River bridge at far left. The aluminum angle will keep the splines perfectly straight across the bridge:
Over the last week or so I have been in the layout room working on laying out the remaining mainline on the lower level. Just as i did in the existing area of the layout, I started by tacking down sheets of 3/4" thick blue extruded foam. Next, I grabbed some leftover Masonite splines from the previous trackwork and, using T-pins and mini clamps to hold things in place, laid out the centerline of the main track. I find this to be a great way of designing a track plan, since it is real easy to make changes by pulling up some pins and moving things around. Once I am happy with a track alignment, I will transfer the track centerline to the tops of the benchwork, add risers, and then install the spline roadbed. This makes it very easy to achieve trackwork that has smooth, flowing curves that look like they belong in the scenery that they pass through.
» Photos
This photo shows where the mainline currently ends on the dropdown bridge that crosses the doorway to the room (lower right of photo). Beyond there, you can see where I have placed the first spline for the future mainline. The straight track in the distance is where the crossing over the Etowah River will be located:
This next photo shows the track as it continues northward beyond the Etowah River. You can clearly see the special construction of the benchwork in this area to accommodate the depth of the Etowah River scene in the distance; the terrain will slope upward towards the foreground where the "regular" height benchwork resumes. The large feed mill located at Calhoun, GA will be placed between the tracks and the backdrop in the foreground of this scene where the level is resting on the benchwork:
This next photo was taken in the same location as the previous one, except the camera has been rotated and is pointing in the opposite direction. The town of Calhoun, GA will be located in the foreground. Although the details of the town have not been established, there will be a depot, a small yard, and a few industries. A local freight will originate in Calhoun and switch all of the industries on the lower level. You can also see the approximate start of the Resaca passing siding, which is represented by the flex track tacked in place to the right of the mainline. In the distance, the Dow Chemical industrial spur will branch off of the siding and terminate at the backdrop:
This photo shows the tiny town of Tilton, GA, which is the next scene to the north of Calhoun. You can see where the Resaca passing siding ends. I have started mocking up Franklin Industrial Minerals along the backdrop. The mainline will cross Swamp Creek at the very bottom of the photo before entering the helix and traveling to the upper level:
This photo shows how the main track will enter the helix. I will not construct the double-track helix until work begins on the upper level of the layout. Until then, the inner track of the helix will function as a return loop (as indicated by the dotted line) while the outer track will serve as a staging track:
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