use of moveable frog switches with DCC : LUSENET : Wiring for DCC : One Thread

Gentlemen: I came across your web page by accident. Happened into DCC page by Allen Gartner. Impressed by the amount of info. Started to build a room-size layout after 35 yeaars of thinking about it. Family, job and life got in the way, as you understand. Can remember when I had to use blocks and rotary switches to make anything go. Astonished at the technology available now to model railroaders. Am building an On30 railroad, using code 100 NS rail. Have quite a few of the old TruScale moveable frog turnouts I saved over the years, as I found them to be very reliable in operation. Can these be used with DCC without modifications, or do I need to make some "adjustments" to them before I lay them? I expect to be purchasing Digitrax, with their sound modules, or ThrottleUp sound modules, if Digitrax not available. Appreciate you taking the time to respond, and making your Q and A forum available to modellers. Thank you. Jim PS: Still unsure as to not blocking track.???????

-- Jim Counihan (, July 12, 1999


Hi Jim: What a fortunate accident! Welcome back to the world of model railroading- You're going to have a lot of fun. Yes the technology is great and after 20+ years of struggling with multi-train control without blocks, it's finally mature.

When I converted to DCC, I kept the blocks for signaling purposes. I also abandoned "common-rail" wiring and went to paired feed wires to each block, gapping both rails. It's easy to do in the beginning and leaves you with lots of options in the future. Example: I can easily re-arrange the sections of railroad assigned to three DCC power boosters. Occupancy detectors are centrally located and easily accessible. #16 Zip cord from All Electronics is cheap!

The old Truscale switchs should work very well. For you youngsters", Truscale made a single pivoting assembly that included the points, closure and wing rails. The wing rail moved against the frog as the points moved against the stock rail leaving no gaps. This also powered the whole assembly to the frog potential. The only risk here would come from poorly dimensioned metal wheels that might bridge the stock rail to the nearby open point. This would instantly trip out the DCC power supply.

-- Wayne Roderick (, July 12, 1999.


Wayne did well in his advice. A few extra notes. The Truescale switches might work best if you narrow the points a hair and widen the gap to prevent the wheels from shorting on the open point position. As to blocking - the only place where blocking will be important is at any reverse loops where you'll need to switch phasing (polarity). That can be done with DCC while the train is moving. Many arrange the turnout control to add contacts for the reversing loop. Very automated operation occurs with a reversing module which is also available. Using blocks and allowing for expansion with signaling as Wayne suggests is really a good way to go. The only thing that the Truescale switches may have against them operationally is that they are brass and that requires a lot of frequent cleaning compared to nickle silver.

-- Ed McCamey (, July 13, 1999.

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