shinohara 3 way switches and where to cut gaps

[Anonymous]

am wiring layout for dcc and need to know wher to cut gaps these switches are non-insulated frogs?

also if a single shinohara is back to back with a 3-way where are gaps in normal 2 way turn out cut?

[SteelMonsters]

Three ways turnouts are the most difficult to power, even worse than double slips. The problem is that the frogs are so close together.

What you want to do is make cuts on either side of the frog. This means that the two closure rails that wing off in the frog need to be cut between the wing rails and the points or the other frog. I do so as close to the middle outside of the guardrails. Also, past the frog needs to be cut to isolate each frog from the other rails. The points and closure rails to the gap should be powered the same as the stock rails. To define each part I will start from the single rail and go in the direction of the three outgoing rails: Point 1, Point 2, Frog 1, Frog 2 and Frog 3. From the single rail looking at the turnout, I will choose the right rail to be positive and left rail to be negitive (referancing DC to make terms easier to identify) There are three routes: Main, Diverge right, and diverge left.

Diverge right. Frog 1needs to be negitive, frog 2 can be any state, not powered prefered. frog 3 needs to be negitive.

Main: Frog 1 can be any state, not powered prefered. Frog 2 needs to be negitive. Frog 3 needs to be positive.

Diverge left: Frog 1 must be positive, frog 2 must be positive, frog 3 doesn't matter since it's far enough away to not cause problems.

( If you don't know the parts of a turnout: Stock rails are the outermost rails, Points are the moveable rails the direct the train, the closure rails close in pretty close and then turn into the wing rails which flare out. The frog is the two connected and expanding rails directly between the wing rails., Finally the guard rails are the rails next to stock rails that keep the wheels from shifting into the frog when taking the gap)

Always gap the rails past the frogs. If they are butted up against each other, make the gap between them. If a longer strech is there, splice in a isolated length of track between the frogs and power it seperatly. If you use signaling, you can extend the frog powered rail to the signal. It has the side benefit of shorting out the power supply stopping a devious train in it's tracks.

When in doubt, draw out the rails and color them in with three colors, two defined as positive and negitive to represent the two power feeds, and a third color to represent transition track that are powered by turnout position. Try your best to keep the positive and negitive colorts as far away from each other as possible using transition rails and make sure that in all the turnout states that the transition rail lines up properly with the trackage the train will be rolling on.

[markpierce]

I have a shonohara 3-way turnout but haven't installed it yet. It is already gapped after the first frog: the rail connecting the first and second frog and the rail connecting first and third frog. Do I assume correctly that spedial feeder wires are needed for frogs 2 and 3 with power dependent upon route selected?