Here is another look at my reference photo that was in last falls Streets and Buildings post. A clear view of one of the overhead wire support structures is shown.
What I found to be the closest match to this were the Tomix 3000 series. I used 1 set of the 3004 ( set of six 2 track ) and 2 sets of the 3005 ( set of three 3 track ) to get full set of 8 overhead wire support structures which are spaced at every 80 - 100 scale feet on the modules with spares of each of the three widths that I ended up with.
Middle insulators were removed on the 3 track versions.
On two of them a section in the center was removed and the two sides spliced to match track spacing. These overhead wire structure models are made of the same type of plastic that many locomotive handrails are made of. It is very difficult to glue together. I found that I got the best results by placing a .010 thickness of styrene between the two halves. I also laminated a .020 thickness of styrene on the top to add strength.
The kits come with horizontal cross members that attach to vertical poles. There are notches on the cross members that hook into slots that go around the uprights. I wanted some reinforcement to this so I added a bead of Walthers Goo.
Each set of Tomix overhead wire structures comes with a spue of mounts that were designed to work with the Tomix track. I used these to make my own mounts. The styrene tubing extends down into holes that I drilled into the modules and up to a height of 2 -3 scale feet. When completed and placed on the modules, the bases will be painted the finished assemblies a concrete color.
The mounting bases were glued into drilled holes on both sides of the tracks. Height adjustments were made so that the structures would be fairly level as shown in the photo.
Here is a view of the structures after painting along with a 651 Series Super Hitachi train. The overhead wire support structures plug into the mounts but can be easily removed if needed for track maintenance.