Trolley Wire

When I started this project I wanted to try to erect overhead. It wasn't all that hard to do 35 years ago when I had an HO layout. The main concern is how it will stand up to the elements -- birds, the dog, falling tree parts, etc. However after seeing a sample that one of the IRM guys did I returned home inspired.......

The line poles and some cross arms had already been placed on the trestle and curved viaduct. I reasoned that this would be the best place for the trial installation as I would be unlikely to fall over it as I complete the landscaping, building placement, etc. This proved to be a sound theory. It wasn't until the following year that I felt things were under control sufficiently to string the rest of the overhead. This was done in late 2007, with the exception of a couple of industrial sidings that will be taken care of in 2008 when we take care of the post-winter maintenance.

Above shows cross arm pinned to pole. Top right shows how 3/8 dowels were used as standoffs to offset the taper of the trestle bents. A hole was drilled into the tie, through the horizontal piece and the pole then a pin installed with epoxy.  At right shows how pin was driven thru pole and into bent. [About three of these were destroyed in summer of '07 by a falling tree branch. They were replaced with 1/4" bar stock.]

I'm using wire supplied by Karl Johnson. It's nickel silver. I carefully unrolled what I needed then went back and fashioned loose pulloffs using mechanic's wire and/or large rubber bands in the form of a slip knot. I tried to keep the wire above the inside rail on curves.

An upturned muck bucket made a good work surface. Some brass ears (MTS and Karl's) some flux, solder and spring clamps helped me to tin the underside of the ear. Wire was also tinned at the location of the ear.

After losing a couple of ears in the dirt, I decided to attach one of the span wires to the ear. The wire is from Clover House. Its  twisted, thin gauge copper, sort of like picture hanging wire but easy to work with.

Here we have a couple of ears attached. The span wire serve is complete at the ear but loose at the pole side, This allows for easy adjustment of alignment. The "insulator" is a chunk of 3/32 heat shrink tubing.

Another view. Ear needs to be pulled back a bit. Cross arm carries two feeder cables. I cheated. These carry current for trolley, plus each rail as the trestle has aluminum rail

Initially tried a small torch. Too hot, too difficult. Switched to 25 watt iron. Used small spring clamps to hold ear to wire for soldering. No picture of this -- not enough hands!

This shows a tap from the "hot" feeder as it leads to the trolley wire. Just a short piece of #20 wire. Insulators are two sizes of beads on a straight pin. 

Feeder cable is actually stuff from Michaels that is used to make jewelry. Comes in 18,20,22 and 24 gauges in various finishes. Spools are wedged onto pole as tension is adjusted.

Pulloffs for the backbone on curve were made from two brass eye pins from MicroMark. Hole in hanger casting had to be drilled out a bit.

I should have rotated them so one was offset 90 degrees from the other. Live and learn for the next time.

Aforementioned pins were purchased to use as eye bolts for attaching span wires to line poles. Holes need to be pre-drilled. Serves have not been completed yet.

Three of the poles on lower Front Street use bracket arms  made from Plastruct shapes. The long "eyebolts" on the right are parts used by model ship builders. The contact wire is a bit wavy here as things are still being "tweaked."

Cross arm with two feeder cables. If you look closely you can see where the two are connected and a tap run down onto the span wire.

Made some fittings as splice ears.. Used brass channel. (Later discovered a abetter way was to use a short piece of small diameter brass tube to make a splice ear. Almost invisible.)

This will be a feed to the trolley wire. I cut the span wire a bit longer than needed, ran it around the insulator on the lower arm then up to the other cross arm where it will be soldered into the feeder cable. Going down a 5% grade here so there's not much demand for current!

Just a few observations as of the end of 2007:

The nickel silver contact wire is about 20 gauge and the feeders are 20 to 24 so, yes, Virginia, there is a bit of resistance. Actually, I can short it out and draw about 2 amps! And, just like the prototype, I need additional feeder taps on the upgrades.

The wire on the trestle has been up for a full year, and with the exception of a falling tree branch necessitating some "maintenance" it continues to function well -- except -- some funky non-conductive brown oxide has manifested itself. It's resistant to chemical removers but is easily cleaned with a couple passes of 600 grit emory cloth.

It's also self-satisfying to watch the pole track on the wire, knowing that the trolley is drawing power from the overhead just like on the 1:1 systems. Didn't get around to any night sessions this year. I imagine I'll see small sparks, again, just like on the real thing!

Its 2015..many of the wooden dowels have begun to rot through, so they've been replaced with fiberglass plant sticks. I've also restrung feeder cable and generally simplified the overall appearance of the overhead. The oxide problem persists. The wire is profiled correctly so the trolley poles track properly, but I'm still cheating by using conventional two-rail power.