Good day all:
The following post covers the construction and operation details of the 300 Loft catenary system I have been working on since 2015.
NOTE 1: Be warned this is a long post. Hopefully someone will enjoy it and get some new ideas.
NOTE 2: This is a 'living' document of sorts. As I have time, I will post edits, changes and / or progress here as it happens.
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1. THE LAYOUT & TRACK PLAN
My 'niche' in this hobby is the design and implementation of robust catenary systems that will power the trains. The third rail would only be to power coaches. I suppose this was due in part to growing up by the old Pennsy main and catching AEM7s from time to time during the 90s, as well as the close proximity of the Port Road and old A&S branch, with a rich history of electric operation.
The first such system I built modeled Pennsy catenary, with my designs for the support structure. That layout began as a single track O27 floor layout, which morphed into a double track electrified 'wall-hugger' system. The support designs were very robust but were not that elegant or parts-efficient. Additionally, soldering copper blips between the aux and trolley wire over the whole layout took forever. Some difficult life circumstances forced me to abandon model railroading for about 3 years. That system is only a memory. Sadly, I took no pictures, but I did take a few crude videos, which I posted on my YouTube page.
Today I live in a semi-detached with a loft area. It is not huge, but was big enough to allow for a decent O scale layout, assuming efficient use of the space. In November of 2015, the itch to build bit hard. After some negotiation with my wife, construction began. I ended up using much of the hardware from the previous layout, which saved me a lot of money, given my tight financial situation.
Below is the loft area prior to construction. I was in the design phase, and had recently acquired an Atlas O AEM7 (my first O scale piece since 2009), the testing of which contributed to the busyness seen around the desk and workbench.
The benchwork started with a duck-under, (seen below in the foreground), and proceeded around the room. I used 3/4" common board from Home Depot, and all the benchwork support screws go into the wall studs. The track plan was completed in March of 2016.
I use Atlas track, which I found inexpensively and in great condition on eBay and from Barry's Trains in Manheim, PA around when he closed. Note the wall under the layout to the right (behind the TV), is the boundary edge of the loft, over which is a long fall to the first floor. As such, I installed the 'guardrail' benchwork along the edge of the system. The ruling curve is O63, which is a compromise. I desired to use O72 (as the wye turnouts are) or even O81, but that left too much of the system in a 'curved' state. I settled on O63 as a happy medium.
In the shot below, the wall corner that is closest to the staging track needed to be modified in order to provide appropriate spacing between it and the tracks. We are looking towards the staging track eastern limit and where it diverges from the mainline.
Below, we are looking toward the staging track southwest limit and where it rejoins the mainline.
The yard below stretches to the staircase, and is roughly 8ft or so long.
I think this is the best track plan I could come up with given my space constraints. Despite the smaller size, I think it still allows for some some decent operation with one or two operators. One can run a mainline passenger or freight, while staging something else or moving cars around the yard / staging area. After some run time, one train can then be yarded, and the other sent on its way.
The other more mundane use of the system is to relax on the couch in the loft area and listen to the trains run for extended periods of time. After a brutal day at work, it is intensely therapeutic and worth all the effort.
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2. THE CATENARY SYSTEM
Catenary construction began April of 2016. My typical method is to model the wire and immediate catenary supports against a prototype, and design the extended catenary support myself. Materials had to be acquired locally, and all were except for the wire, which I purchased as a 125ft spool of 18g from Small Parts. I also wanted this system to be a bit more elegant, consistent and parts efficient than the previous Pennsy system was.
Since I wanted to model some European electric operation in addition to Amtrak, I decided on the newer style catenary Amtrak installed above New Haven, which has a Euro feel to it. It's also a little easier and less time-consuming to fabricate, given there is no aux wire. The image below is a good shot of the catenary style I am modelling.
Before I erected any cat poles, I had to determine where they would be installed, which obviously was critical to good wire placement and thus pantograph travel. As the prototype image above shows, this style of catenary uses tensioned straight sections between curves, which is great for even pantograph wear, but more challenging to properly place the cat poles. This challenge was overcome with sewing thread and some small nails. The wire had to stay within the gauge, so I installed a nail at every O63 curve joint, which kept the sewing thread inside the gauge.
In the the straight runs, the thread was pulled toward the inside rail. (Below)
The immediate cat supports were modeled after the prototype above. After some trial and error, I arrived at the plan below.
I then used a piece of scrap board and dremeled out a jig that would allow me to solder the separate pieces together. The red line was a rough estimate of how the bottom most piece would be shaped, where it directly supports the trolley wire.
The supports are made from brass rod at Lowe's. After more trial and error, I got in a good rhythm of bending the brass just right as to fit the jig. The first prototype cat pole is below.
While this was a good start, there is an obvious weakness inherent in this design, which is where the bottom arm is soldered. When I installed a test section of wire under full tension, some of these single joints holding the bottom arm began to fail after only a few days. This necessitated a minor change in the design, shown below, along side a failed first generation support arm.
It was then fitted to a cat pole.
Of course, the the top part needed trimmed to match the bottom, but the double-solder joint of this support has yet to fail anywhere in the system. The pole is 3/8" threaded rod from Lowe's. Aluminum grounding lugs and nylon spacers hold the support in place, all available at Lowe's. There is a lock washer between the nuts, between the aluminum lugs. This gives me solid support, complete adjustability along any axis for fine adjustments in wire position and height, and most importantly, no cat pole is hot.
There is also a prototypical catenary support that is 'reversed', often found in curves and tight spots. The following is a good example, toward the top-left corner.
The jig will do either support.
Once I cut and bent the brass to fit, I fastened it down and soldered it up. This technique was used for both support types. While a bit busy, this arrangement (or something similar) allowed me to make fine adjustments before soldering, and to get a good joint. I used a 100w Weller pencil iron.
These also need some trimming, so the top joint matches where the bottom piece ends. The other end needs trimmed as well, where the support mounts to the cat pole.
While this design was generally effective, a weakness appeared when the reversed support was used on the outside of a curve.
When wire is under tension using this support, the tension force pulls somewhat down and inward. As can be seen above, this negative force vector defeats the the upper-most joint over time. (NOTE: it is quite a startling 'bang' when one of those joints gave way). Rather than redesigning the entire support, it became easier to simply to use this support on the inside of a curve, such that the force pulls somewhat up and inward. This positive force vector actually causes the support to compress, adding somewhat to its strength.
Once the cat poles for a given section were up, it was time to hang wire. The sequence was to hang trolley wire first, then aux wire, and finally the support catenary between the two. For the mainline loop, there needed to be a way to tension the wire without 'cheating' by using poles at the end of each straight shot and soldering un-tensioned curved wire between them. That's not prototypical and looks silly. Naturally, this wasn't a problem in the yard or staging track, as they all end with bumpers, such that a pole could be placed after the bumper and still be reasonably prototypical. This debacle led to the use of 'pull-off points'. This was were one section of catenary would 'pull off' to a tensioner pole, and another section would 'pull on ' from a tensioner pole, meet in the middle, and continue to the next section with no gap in the wire. There were 8 such pull-off points, 2 per section. See the diagram below.
Wire is tensioned using wall-drillers and beefy #10 screws. Drill 2 holes in the threaded rod, one for the trolley wire and one for the messenger wire, (roughly 1.5" apart). Install the screws and wall-driller, leaving about a 1/2" gap between it and the pole to allow me the slack for applying tension. Dremel a hole in the wall-driller, thread the wire and solder. To ensure some elegance and efficient use of supplies, tensioner poles doubled as cat support poles for the mainline. It looks tacky to have poles standing right next to each other for different purposes. While it was tricky to get everything aligned properly, this arrangement ended up being a very effective design. See below.
The spot where pulled-off wire sections met and diverged to their respective tensioner poles was in the middle of straight runs, as the diagram above showed. I expected this to be a lot harder to implement than it was. I simply dremeled a deeper notch in the cat support, and both wires slipped in.
For the shot below, note the top-right and bottom-left wires are the same, being pulled off out of frame to the left. The top-left and bottom right are the same wire, being pulled off out of frame to the right.
Below is the same wire-section meet from track level looking up. Naturally, diverging wire was pulled upward toward their respective tensioner poles, such that the pantograph sees a nice smooth transition from one section to the next.
Below, the same wire-section meeting point is in the foreground, while one of it's respective tensioner poles is in the background prior to the curve. Once tension is applied from both ends of a wire section by tightening the wall-drillers, the wire is soldered to the cat pole supports.
I exert a fairly high amount of tension on the wire. Hence, I always used safety glasses when tensioning any wire. Below is an example of a tensioned wire outside the yard. All poles are bolted to the benchwork, through a metal mending plate at the base of each pole. Tensioner poles or those at a bumper are re-enforced through a second metal plate below the benchwork. The image below is also a good view of the screw / wall-driller tensioning assembly.
With all these logistics solved, the cat poles for a given section were planned, distributed and erected.
At times, there were poles and other related support structure all over the place.
Once poles were erected for a given section, I could actually start stringing wire. As I mentioned above, the sequence was always to hang / tension trolley wire first, then hang / tension messenger wire, then install the support catenary in between. Any section is considered 'safe' once all three of these components are in place. That way, any break would be controlled by the surrounding wire it's soldered to.
Once one end of wire for a given section is fastened to a wall-driller...
...it was time to break out the spool and hang wire around the section in question.
Wire height is roughly 4.75" from rail head to trolley wire. This was a bit higher or lower in places to simulate stations or other areas where wire height varied from the norm. Heights were measured with a ruler, or the pirated scrap of an end table, cut to size.
The support catenary was easy to fabricate, but the biggest pain in the neck of the entire system. First, I too a pair of tweezers and stuck a few piece of rubber on the ends, procured from a failed hard drive. For clamping wire, this was a great way to dampen vibrations and allow me to work with everything moving around.
Pieces of support catenary are the same 18g wire in 1-2" lengths, depending on where in the system you are. Use pliers to bend a curl in the top, drape it over the messenger wire, and clamp the bottom to the trolley wire.
Solder it up, trim the bottom, and use a dremel with a stone to smooth the bottom for pantograph travel. Smoothing is critical to wire travel, and also the noisiest, most bothersome task on the system. I still do some smoothing from time to time, as the pantographs tell me.
Once a wire section was done, it needed to be mechanically certified for height and position with a pantograph. This was accomplished with a stripped down Atlas AEM7, fitted with a stock pantograph (back), and a scratch-built pantograph (front), and 2 green LEDs for electrical tests. The section was then electrically certified by checking each pole with a DMM to ensure electrical isolation from the wire.
The yard and staging tracks presented the major challenge of joining wires over turnouts. The solution was to use some brass i-beams from HO catenary I had in the spare parts collection.
Cut a piece about 3/4" long, and dremel both ends smooth in an upward fashion.
Drill some very small holes and run wire into them.
Hang the whole thing up. Note the wire in place is behind, the wire to be joined is in front. Both wires clamped into the joint very nicely.
Finally, solder the assembly and trim any excess.
The yard entrance below was one of the more complicated areas to wire. There is a "double-duty" pole, where one support is on the staging track (to the left) and one in the yard throat, (to the right)...
...and then the 'cornerstone' pole of the yard. It needed to be supported by a turnbuckle to keep it straight. This pole is the endpoint for all wires in the yard.
Below is a full view of the yard area, looking west. The mainline is the inner-most track and the staging track is adjacent to it.
The final major construction hurdle was to join the turnouts that link the mainline to the staging track, which are on separate electrical circuits. The solution to that was a bit more parts-intensive than I had hoped, but it lent to a very sturdy structure and complete operational success. To start, I had to mount a pole in the 'middle of nowhere'. Given the large structure to come, I used 1/2" threaded rod for the cat pole.
Lay out the hardware, with the pole lined up with the center of the turnout. This is the basis of the turnout support structure. Note the beginnings of a wire-section meeting point on the same pole, off the mainline.
Assemble the hardware, with two half poles pointing in opposite directions, such that the wire will overlap, but stay electrically separate.
Install a support brass piece and wall-driller tensioner on each side.
Finish the wiring on the mainline, adjacent to this turnout and branch a wire off the mainline toward the turnout structure. It took 3 tries to get the spacing correct so the pantograph didn't slip off.
Below, success.
Below is the completed turnout structure, from track level looking up. The wire pulls off on each side, and stays electrically separate. It's also a seamless transition for the pantograph. Ensure the wall-drillers' threading is above the wire plane!
Below is the same, also including the wire-section meet and diverge point, as mentioned previously. This entire assembly is supported by the single 1/2" pole. Since everything is bigger on this pole, (1/2" pole, aluminum lugs, bolts, etc), the catenary support didn't quite fit properly. As can be seen, I had to use some additional elbow grease to make it fit.
Below, a similar design was used at the other mainline-staging track junction, near the southwest limit of the system.
Below is the same junction, as seen from above.
Below is the same junction, from track level, looking southeast. Sorry for the blown-out image.
The completed catenary system can be seen below. It's quite a change from the first images with only 'bare' track.
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3. THE TRAINS, LOCOMOTIVES & PANTOGRAPHS
At long last, it was time to test trains and actually make the system work.
My favorite trains have always been the electric-powered Amtrak trains of the 80s and 90s. The paint schemes then were much better. It's nice to see a 'new' phase 3 paint scheme making a comeback today. Call me backward, but the Amtrak 'Chevron' logo looked the best on the old Amfleet 1s. The AEM7 is my #1 locomotive, followed by the E60x, of which I am patiently waiting for a decent model to arrive. The GG1s were rather before my time. I appreciate them, but don't have a burning desire to run them.
I have one of the new MTH AEM7s, and a string of Phase 1 decorated MTH Amfleets. I didn't even realize MTH made Amfleets in Phase 1 paint, until I happened upon them while browsing Western Depot's website and promptly grabbed up the only set they had. They have the simulated aluminum finish that the AEM7 has, with the added bonus of people figures inside.
I am a stickler for details, and I am aware of some deficiencies with this train. The AEM7s didn't have ditch lights when Phase 1 painted Amfleets were around. The blue paint on both models is too dark. MTH Amfleets are not quite to scale. Finally, the AEM7 body numbers are too skinny a font, (the latter of which is the subject of another post). But, given the overall look of both models, the sounds and functions of the new AEM7, these few deficiencies are forgivable. This is the coolest engine I have ever owned, hands down. I will shortly post some videos of this train in action.
MTH pantographs are known to be troublesome, but the ones on the AEM7 are well-sprung and of relatively good detail. However, the pantograph head isn't right, and in any case, too light-duty for use with catenary. Therefore, scratch-built pantograph heads were required.
I started by stripping the paint and cutting the ends off the existing pantograph head. I then made two new pantograph strips, using K&S Engineering brass bars (#81024), just about the width of O gauge track. I used pliers and the outside curve of a Tupperware container to shape them as seen below. The strips are not completely straight as the original Faiveley DS-11 pantographs were, but a slightly bowed strip head makes for better travel along the wire, which is more important to me. Most European locomotives have slightly bowed pantograph strips.
Next, I used a piece of dowel wood and a push-pin to position the new pantograph head pieces. I used the old head to know how to space the supports. This is a tricky and time-consuming step, to get a pantograph head to look like this. Pieces move around very easily. A good dose of patience and Aleve are required when building these heads.
Solder it up. I used a 100w Weller to get the job done right, and quickly.
Next, balance the pantograph on the new head, and use another small dowel and 2 push-pins to hold the whole thing still.
Solder the new head to the old one, then dremel the heads to get any residual flux remains off.
With both pantographs done...
...mount them back on the motor. I had to make some adjustments so they would collapse on the roof a bit more cleanly.
All pantographs were well-lubricated with silver conductive grease on the head and joints.
Test the motor. Look ma, no rollers.
Finally, I used an MTH Railking MP54 coach as a catenary test / maintenance car. The pantographs are from a Japanese brass model, and work great as they are without modification. The interior is lit, and the rollers on the bottom can transfer overhead power to the 3rd rail, making it a 'HEP generator' of sorts for any coaches that might run. While this isn't really necessary (or practical), I took satisfaction in knowing that all parts of the train were powered by the overhead wire.
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4. SYSTEM CONTROL & DCS IMPLEMENTATION
The 'final' step is command control. Referring to the image below, note the back plane where the white cable modem and black WLAN router is, under the curve of the layout. The DCS TIU and AIU (sitting on the benchwork above), will mount beside them, vertically. I use a current Revision 'L' TIU, running DCS v5.0. The black box on the workbench in the foreground is where the power supply, electrical control circuitry and turnout control (via DCS or manually) will be housed.
The control circuitry consists of a few beefy Hammond transformers, (19VAC at 10.5A), a DC power supply (for the LEDs and relay coils), protection devices (MOVs and fuses), other toggle switches and various indication LEDs. Center-off toggle switches for each turnout allow the user to select which turnouts are controlled by DCS, which turnouts are controlled manually, or which turnouts are off. I use capacitive discharge circuits and latching relays to actually fire the turnouts. There is no turnout 'memory' built in, but for a small layout with only 7 turnouts that can easily be eyeballed, I didn't stress over that. There will be indication of the 'last' turnout status via LEDs. The user can turn sections of catenary on or off via LED indicated toggle switches. There is also provision for the insertion of a user-provided transformer for regular 3rd rail operation, DCS or conventional, for visiting locomotives.
The control box is not yet built, as I have been busy testing trains under the wire, but it has been started at least. The above design for control is still changing some as I test the system and come up with more efficient circuitry.
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For now, I am at the point of building the control system, and doing shakedown runs of trains at speed under the wire. While this is 'only' a model system, I can attest to the fact that it has all the problems of the real system. Alignment frustrations, contemptible pantographs, the occasional busted support and numerous lacerations, abrasions and stains. However, I have had no accidents or lost pantographs as yet. In any case, I immensely enjoy building systems like this, as well as conquering the challenges in design and repair as they arise.
If you've read this far, THANK YOU! I hope someone found it an enjoyable read and perhaps provoked some new ideas. Any comments, criticism, questions or whatever are welcome.
And what is wrong with your AEM7 that it needs such an overhaul?
This past Friday I finally had enough and just posted it. Then proceeded to edit it repeatedly since. 
