common rail: one wire goes to every positive or negitive terminal or every pack. and the other wires are part of the circut. bi wire: the two wires come out of the pack and one goes to each rail, through a few rotarys or DPDT switches and you can control different trains
"Bi-wire" (a term I had not heard in 50 years of MRRing) is the same a "Direct Home" wiring (another highly non-descriptive term). In this case the feeds to BOTH rails in a block are controlled through block selector switches. Common rail wiring ties the feeds from all "N" (or "S") rails together, with block selectors switching only the other rail.
Ah, that's what I was guessing. Do the rails need to be gapped differently (gaps in both rails, maybe)? I might have to try this on the new layout; I never had much luck with common rail wiring, or wiring in general...
just to stir the pot some more... Well, that's a pretty incomplete description of common rail. It should be "Each pack as one terminal connected to a common rail (or bus). The other terminals go through rotary or DPDT switches to the other rail."
Just to correct your recipe ... it should be: "The other terminals go through rotary or SPDT switches to the other rail." You could use DP of course, but while 2 poles are needed for bi-wire you only need a single pole for common-rail.
