Correcting A Crossing Circuit - With Expert Help

As regular readers know, we have a fully automated grade crossing on the Onondaga Cutoff.  Just west of CP 277, Highbridge Road crosses the Chicago Line, and the grade crossing is protected by lights and gates mounted on posts.  These are automated through the use of sensors placed along the track - distant sensors, located so as to provide gates being down before a maximum-speed train's arrival, and 'island' sensors on each side of the crossing so that the gates rise immediately after a train passes.  

I used the Azatrax system for this as detailed in the March 8, 2019 post https://onondagacutoff.blogspot.com/2019/03/protecting-grade-crossing.html and have found it to be excellent.  

However, it was designed for a simple double track main line application - not one with a crossover between the distant sensors and the crossing.  Essentially, where the diagram above reads 'Track 1" there are switches that allow trains to cross over in each direction.  Therefore, depending on the sequence of traffic, the machine would be deceived by certain crossover moves, since the incorrect sensor would be triggered or missed, and that lead to unprototypical operations.  

After one of the Facebook Live video releases on the OC Facebook Page ( https://www.facebook.com/onondagacutoff/ ) a viewer commented that he could help with this.  Matt Paquette, who is a professional signal maintainer for a major northeastern freight railroad, advised that we could use the internal contacts in the Tortoise Machine to re-wire the distant 'E' and 'W' detectors to provide proper detection for crossover moves.   Matt built a new diagram to follow.

Essentially, the Q1 output needed to be routed through the internal contacts in the Tortoise machines so that the grade crossing board would see the proper distant detection for the move.  It took some doing and soldering in tight clearances - not my best work - but it's functional, and seems to test out.  The true test will be an operating session!  

So, thanks to Matt, the Onondaga Cutoff just got more prototypical.   Matt's expertise helped where I had run out of choices, and this becomes another example of 'Let Experts Be Experts.'

Continuing the Deep Staging Process

 It has been a month of expectation and waiting.  

Waiting for the vaccine to be available for COVID.  Waiting for the vaccines to catch hold nationally so life can start to return to normal.  Waiting for some HR changes at work to take effect.  Waiting for (hopefully good!) feedback on several model railroad media fronts.  Waiting for the book to arrive for sale.  All of these things should be great when they come to be, but as my favorite musical artist sings:  "The Waiting is the hardest part."  

And so, as a place to ground out the energy and the angst in the waiting, I have continued to pour efforts into completing the deep staging installation, with a goal of having it operational by April 1.   It has taken each minute I have given it, and asked for more: this is without question the most difficult construction I have tried on this layout.  

We left off last time laying track for the tangent.  That task was completed shortly after the last post while the tangent stretch was still on the floor of the space, allowing for track to be aligned where I could see it without having to guess. 

Once the track cured, I installed all feeder wires, also here on the ground.  You can see the gentle bend in the middle of the tangents, required to deal with the challenging clearances once installed.  I added re-railer sections, upper right above, just in case.  The black steel brackets you can see in the upper left will support this installation, which needs to be close to the aisle at the left side to avoid the diagonal supports ahead to the right.  But, immediately past that, the roadbed will need to curve towards the wall to the left and begin the climb up to the Island level.  

Many thanks to Tom S. and Ralph H. for coming over to lift, shift, and slide this assembly into place!  We made the big lift - and it went just about perfectly.  Thanks to measuring three times, cutting once, and the foresight to assemble this piece on the floor, we were in good shape.

The alignment was exactly what we needed.  Clearances all checked out.  I however left it loose on the brackets pending the installation of the curved section - since the curve will be the link to the existing layout, it must be finalized first.  Now it was time to tackle the curved section installation.  

I had been thinking the curve design and install over for months, debating the approach with myself and with Scott S., a fellow civil engineer.   Like the tangent section, there was no way to lay track once the roadbed was installed just 10" below the top section.  Worse, the tight curves required here (20" radius in places!) made precise installation critical.  The trackwork needs to be perfect at all joints and respecting all clearances for trains to handle this - there is no room for error.  

The new curved benchwork too would be too long and large to be slid in from the aisle or floor.  It didn't clear the adjacent parts of the layout.  

The only choice left was to paint the wood ahead of time, add the guardrails ahead of time, then assemble the curved plywood in two pieces, after which track could be laid - all while the assembly was temporarily supported out from under the top level.  But the only place to do that was on top of the uneven mainline ramps behind Iroquois: it is the only place I could fit the assembly where it could then be rotated into position.  Putting heavy plywood over HO scale mainline track is always tough to stomach.  And then, after all that, the whole thing would need to be rotated counter-clockwise over the Island tracks, along its permanent path slid between existing Island tracks and the layer above, before being set down onto the supports.  

Ugh.  Lots of room for mistakes and collateral damage.   BUT - a clear path forward, and frankly the only possible one.  

Even the clear path forward had its struggles.  Here I am in one of my 'layout yoga' positions, on a ladder on an angle bent over mainline with my head against the ceiling, laying track that had to be exact.  Not fun.  

As the track cured, I double checked clearances again, even taking several of my longest locomotives and pushing them around the curve to ensure they cleared the sides and each other while on adjacent tracks.  It was tight - but it worked!  I weighted the track as seen above, a view where you can see the test engines too.  

Once the track cured up, it was time to install 36 different feeders, ensuring that each piece of rail has its own hard-wire connection.

I continue to stand by my claim that resistance soldering, the technique shown above, is a clearly superior way to solder wires to rails.  I was done with all that in one evening with only one melted tie to speak of.  Not bad, and at least I could do it standing up!  

After 5 long nights of late and hard work on this, now we can see the results - and I think it paid off.  Here's the smooth curves of track using Atlas curved switches to save space.  With all that work done, I cleaned up my tools and equipment, thought through the issues one more time, and took the plunge!

With a few bumps and strains, and a sudden satisfying THUMP, the curve slid into its spot.  I had to carefully then adjust it so the extra track from the tangent piece ended up above the curved end.  I fastened the curve in place with risers as seen above, then made the adjustments to ensure the tangent piece lined up, which was then too fastened in place.  I had left 16" long tails of flex track in place on purpose on the tangent to smooth the joints, and those needed to be trimmed to fit exactly over the transition. 

With some careful measuring and lots of time, I trimmed the track using a Dremel tool since the big code 100 rail had destroyed my rail nippers.  The backup plan worked great, though.  The track slid into place.  I spread adhesive below the loose area, then slid joiners into place and laid the track.  The result was better than I had expected, shown above.  Yes the track is old used Atlas Code 100 flex - ugly stuff by today's fine standards - but robust and cheap and therefore perfect for hidden staging areas!

The final step was the final joint between the curve and the Island staging subroadbed, which I did with steel strips for extra rigidity at this odd joint.  With both routes descending, there is a lot of torsion on these bars, but they are more than up to the task.  

So while the waiting takes so long and so much energy, it is being great to have this project to plow along through.  Next time we will look at final cut-in of the yard to the existing track, and the installation of Tortoise machines and controls.   Never a dull moment on the Onondaga Cutoff!

Rewiring the Island Control Panel

We all continue to hold the line with COVID response.  Railroaders are still working, myself included, which I am thankful for.  Many are staying home to combat the spread.  Almost all of us, however, have more time than we used to at home.  Nights or weekends, or all days combined, those of us that are modelers have more time to pour into things while we wait for the virus to pass.

After finishing up the details last time at CP 277, it was time for me to 'bite the bullet' and tackle a job I'd been dreading for nearly 3 years:  relocating the Island Control Panel, the toggle switch board that controls the turnouts leading to the Island engine storage tracks.  This would require cutting in new panel, using terminal blocks to connect 14 pairs of wire with the switch machines.  

Thanks to Nick A's artwork, I had the panels printed up about two years ago.  They sat in the project box since then.  Since it was time to get started, I began to think critically about the details, and while my brain worked on the vision I went ahead and marked the new panel up for drill locations.  I drilled 5mm holes for the 5mm LED bulbs, and 1/4" holes for the push-button and the toggle switches for control of the Tortoise machines.

This created plenty of flash which I cleaned up with a #17 x-acto blade. 

 This particular panel was printed on PVC plastic, since it was going to be installed in an area of the fascia with some bend to it.

At last it was time to take the big step of cutting the new location into the fascia.  I measured twice, drilled out the corners, and used a jigsaw to connect the dots.

While several locations had been debated, this one was selected for the ease of use by the Trainmaster, and subsequent improvement in yard efficiency.  Still, always hard to make that first cut!

The new hole meant it was time to forge ahead.  No going back now!  

I added lights to the new panel one by one, and once the first batch were installed it was time to move the push-buttons that control the turnout hooked up to the PSX-AR board.  

The PSX-AR can be thrown by a momentary-on push button, so it was essentially a short that would throw the turnout.  I'd purchased a 25' length of 14-pair, 24-gauge conductor cable.  I used the first few for these push buttons and gave it a try - and no luck.  The message wasn't getting to the PSX-AR before it shorted out the Island.  No good!  I'd hoped I wasn't in over my head with this.  

What to do?    I remembered from school at Syracuse that the longer you run a cable, the higher the resistance for the power.  When you're talking tiny cables, that is even more of a concern.  Could that be the issue here?  I ran a 25' pair of 20 gauge copper wire, made the connections...and it worked.  Relief!  

For the rest of the toggles, however, the tiny conductor cables worked fine.  So it was time to get rolling with disassembly of the old board, and moving things circuit-by-circuit to the new one.  The old board held up pretty well for a temporary fixture.

I removed the mounting screws and took the wires off the back of the panel one by one.

These were then adjusted to run to a new trio of terminal strips, from which I could connect them to the 25' cable to run to the new panel.  

Numbering these allowed me to match each end with the correct colors and function, so that I could attach the far end to the appropriate terminal on the new panel.

Slow steady progress is key here, and testing as we go keeps us sane.  I caught a few small mistakes immediately.  The idea here, like on the staging panels, is to 'follow the yellow brick road' on the panel:  that's the route that is lined up.  Since polarity matters with the Tortoise machines, it took some trial end error to keep it logical.  

After several nights and a whole weekend of this work, though, it was coming together.  I estimate it required 36 hours of work to get this right, but in the end, I am very pleased.  It works perfectly.  Further, finishing construction here now allows me to hang skirting and clean up the area with some new foam-rubber tiles.  

Here's a view of that area of the layout now - what a difference!

Another big project brought to completion by COVID-19.  I'm making lemonade out of those lemons this spring!  

~RGDave

Wiring Interlockings

Interlockings, controlled locations on railroads where trains can change tracks and signals can be displayed by a dispatcher or operator, are very complicated installations. Turnouts themselves are complicated, and so is the circuitry and wiring to control the turnouts. This chaos is the underside of the staging level at both ends of the staging yard. This shows first-hand why colors are so important for organized wiring - it is the only reliable way to tell what goes where! Some of this will be cleaned up using zip-ties, and I plan on labeling most of the origins and terminals so as to provide some insight during future adjustments or electrical problems. This image shows a typical installation for a pair of the Circuitron 'Tortoise' machines. These come with a mounting jig, allowing the installer to locate the machines using a small hole drilled through the benchwork at the location of the throwbar on the turnout. Four pilot holes are drilled for mounting screws, and the machine is installed from below the subroadbed. I had to check the alignment several times in order to get the location just right, but it has worked out well so far. This is the 'heart' of one of my interlockings, CP 295. This is the 'west' end of my staging yard, and this terminal strip is how I have routed a separate power suppy to the switch machines. While I used red and white wire for track power, I have used black and green for switch power, and will someday use blue and yellow for signal power. The heavier 14-gauge green and black wires lead to another terminal strip which is the location from which all my switches will be powered, and it in turn is wired to an old transformer set to 10 volts.

The nicest part of the Tortoise machine design is that it is constantly under power, and simply will stall once the points reach their full throw. This means that the machine will not burn out from constant power, which is a nice change from the cheaper 'snap' switches I was used to.
Here is the organized chaos of the back of a model board, the 'brain' and control center for an interlocking. These are double-pole, double-throw switches that essentially reverse the DC power to the machines, which simply makes them spin one way or the other, throwing the switch. The thin orange and white wires run from the switch to the Tortoise machine. For now, these are mounted in a simple cardboard mockup of what will soon be a black plexiglas model board, with white lines representing tracks and decals for labels. I will also be installing LED's as indicator lights, although not until the final model boards are in place.
The temporary model boards for each end of the staging yard... And, finally, a close-up shot showing the throwbar itself on a Micro-Engineering #6 switch in the staging yard. If you look at the close end of the throwbar, you can just barely make out the end of the steel wire that links the machine to the throwbar and moves the point rails. It's a nice set-up and worth the extra money compared to other machines.

This completes the work on the staging level that must be done ahead of the second level! It's a major milepost in construction. This weekend, Rick & I will be installing the benchwork for the second level, and then we're back to installing roadbed, track, and more interlockings.

Stay tuned!