Turnout article in July CTT

[lionelsoni]

This article presents a reasonable scheme for saving some wire when wiring up turnouts.  However, the description and illustrations have some technical problems.  One is that the text consistently refers to the common as "ground", while the illustrations call it "Common (U)".  This inconsistency and not quite correct use of "ground" may puzzle the novice reader, but the association of "common" with "U" will surely cause someone problems.  The U terminal is indeed the common on Lionel transformers with multiple variable outputs (not the same as "multi-control).  But it is not the common on those with single variable outputs.  This confusion crops up regularly here on the forum, most recently within the past week.

However, since the transformer shown in the illustrations seems not to be used for anything else and there appear to be no control rails used for anti-derailing, its "common" is not actually common with the layout.  This makes possible a wire-saving measure not contemplated in the article, that is, that the common (center terminal) of each switch machine could actually connect to the layout common (the outside rails) locally at the turnout.  Then the transformer's common (whichever terminal that is considered to be) would also connect to layout common at the control panel; and the center terminal of the turnout controllers would be fed from the transformer's other terminal.  This completely eliminates any need for the wire shown in blue to run from switch machine to switch machine.

Another economy not mentioned is the grouping of turnouts, with one or more controlled by a shared controller.  The large photograph shows an opportunity to do this.  Notice that, when the leftmost turnout (under the locomotive) is lined as shown, the only useful alignment for the next turnout is straight, not diverging as shown.  For a crossover situation like this, there are only two useful turnout alignments, crossing over and not crossing over.  Therefore, the two turnouts can be operated by a single controller.  Many layouts, particularly one like this with 19 turnouts, probably have a number of crossover-like arrangements and other turnout combinations that can share controllers, saving operator effort as well as wire.  I know I have several on my layout.

I just noticed something else.  The caption for the two small photographs at the bottom of page 62 says that the switch machines "require three wires", which is no doubt true.  But the one on the right has only two wires attached that I can see.