Another Question about Turnouts

[Nscale]

Just thought I'd see if someone might be able to answer and explain a basic question I have about turnouts. I have some N scale Kato Unitrack, and I've found that when I run an engine through a turnout in the "opposite" direction and with the switch flipped (as illustrated in the right example below), the engine stalls.

Granted, the manual (shown above) even warns that a short can be caused when running the train straight through the turnout with the switch flipped. I have no doubt the documentation is correct, but I was just curious if someone could explain exactly what's causing the short, and whether this is an issue unique to the Unitrack turnouts or if it applies to turnouts across the board.

Along the same lines, I also discovered that if I try running my rolling stock through the turnout in the "opposite" direction with the switch flipped, the rolling stock will always derail. I guess I've come to the conclusion that for a train to pass straight through the turnout, regardless of which direction the train is traveling through the turnout, the turnout must be routed "straight" for the train to pass through properly. Is this the case with all turnouts, or will some makes and models allow an engine and rolling stock to pass through straight regardless of the direction of the switch?

 

[waltr]

I can give you a couple of quick answers but I an not familiar with every turn-out design.
There are different turn-out designs and some do allow a train to run through as in the right hand diagram. These turn-outs allow this for two reasons: 1-The points are sprung loaded and will move by the train's wheels. 2- The point rails are electrically isolated from each other and each point rail is electrically connected to it's adjacent outer rail.
Note the gap in the two diagrams in your post. This is showing that both point rails and the frog are powered from the rail a point is touching. Therefore if the train runs through as in the right hand diagram the points are forced over (down in diagram) and short the rails together.

There are a number of other ways to power to parts of a turn-out. The PECO turn-outs I use (isofrog) the point rails are isolated from each othe and are connected to their adjacent rails. Also the frog is totally isolated.
On the my hand laid turn-outs the frog is power router and the points are connected to adjacent rails.

 

[Cjcrescent]

These are called power routing, or select control turnouts, and when the loco runs into them as in the rt diagram, a short will occur. These are also known as "DCC unfriendly".

The solution to prevent this is easy. Place gaps into all the rails behind the frog. If you've ever built a layout to run multiple trains in DC, then this would have been part of the wiring rules for the layout, unless you did it using common rail.