Replacing My Last Twin Coil Switch Machines

Ever since I watched the Allen Keller Great Model Railroads video on Roy Kuykendall's layout, I've kept one of his remarks in mind: "The electric switch machine for turnouts is one area that desperately needs innovation. The electric switch machine is an elaborate little device the makes a pair of points switch just a few fragments of an inch on a horizontal line. In order to switch, three separate wires are needed to connect to a control device on the power panel. There is a need in the hobby for something much simpler, more durable, and more inexpensive than these current devices."

Actually, you normally needed six wires, three to control the twin coil solenoid, and another three to power the frog via the switch machine relay contacts. I think Ron made those remarks before the Tortoise switch machine was in general use. I think I remember getting my first Tortoise about 1987 or so. The Tortoise site suggests it was introduced in 1986. I built the layout that was the 1.0 version of my current layout starting about 1988, but I had a supply of twin coil machines from prior layouts and used those for most of that layout, which I moved to the current location in 1993.

When I rebuilt and expanded that layout into the 2.0 version then, I kept the twin coil machines on the 1.0 section but moved to Tortoises on the new and expanded construction. In the years since, the twin coils have gradually worn out, while converting to DCC was another driving force that made me want to update switch control, However, by that time, I was old enough that I no longer wanted to climb under the baseboard to remove the twin coil machines and install new Tortoises in their place.

As I pondered this, I began to realize that if I simply replaced the HO turnouts (mostly from former Walthers Sinohara) with Kato Unitrack equivalents, these had switch machines built into the roadbed. Not only that, but they powered the frogs and routed current internally as well. The Kato solenoid needs only two wires for control, and with frog power and current routing internal, no extra wires are needed tor this. As a result, we've moved from three or six wires with twin coil switch machines to just two wires with Kato Unitrack.

I don't know, if I were to build a whole new layout from scratch, whether I'd start with Unitrack. If I were younger, I might look at other new technology. But given my age and physical capabilities now, Unitrack means I could build a pretty satisfying layout without the need to crawl under the baseboard.

In any case, my layout had three remaining twin-coil switch machines at the back of Zenith Yard, well past the point where I'd want to reach under the baseboard to do anything. Below is the area in question, with o,ld Shinohara code 7o switches:

The Unitrack HO #6 switches correspond almost perfectly with the length and angle of the old Sinohara code 70 #6.

TRhe shots below show the progress of the tearout and demo:

And the shots below show the reinstallation of replacement Kato HO Unitrack #6 switches and some of the additional Unitrack:

I just left the twin-coil machiness where they were under the layout and routed the Kato switch machine wires to new DCC accessory decoders that are controlled from the DCC command station.