Question about multiple transformers on the layout

Sounds fine to me.

The other approach is to have one transformer dedicated to one main line and its associated yards and the other transformer to the other main line and its yards. The advantage of this approach is that you can set one main line to constant 18 VAC to run DCS/TMCC/Legacy engines and the other main line under variable voltage control (from the other transformer) to operate your conventional engines.

I am not sure why the need to power the track(s) by all four throttles on each ZW.  The object normally is that each Transformer is a "Cab".  I may be off here but I always equated the Term Cab to be as being in the Cab of a Locomotive.  So with two transformers you could have to "Engineers" operating two Locomotives.  When operating in conventional mode running more than one locomotive requires all your attention as you clear a Locomotive into succeeding Blocks.  Running two Locomotives would in my mind be mind boggling and subject to catastrophe(s).  Also if you are capable of running four Loccomotives simultaneously, conventional Locomotives require a great deal of eletrical power, so the output of the ZW is divided over four Locomotives.  Others can comment on whether the ZW can run four conventional Locomotives simultaneously.  So this is all my opinion so have at it with your comments.

What I would do if setting up a conventional Pike, is use SPDT, center off switches.  This would allow each Cab/Transformer power each of your blocks through it dedicated switch.  This allows each Cab to align the Blocks for the Locomotive being controlled by  two individual Cabs.  So for instance lets say you have four blocks.  You flip the switch for the Block to the Cab1/Transformer1 to power the block your Locomotive is in.  You would, also assuming the next block your Locomotive is going into is vacant, could also be aligned for your Locomotive through the switch to your Cab/Transformer.  As your Locomotive leaves its current Block you flip the switch to the center position to the middle off position showing the other Operator that the block is vacant and if necessary can be flipped to the Cab 2/Transformer 2 to allow the operator to enter the block.  And the other Operator would be doing Likewise aligning the block for its Locomotive. Now a rotary switch could be used so that both Throttles on each Transformer could be able to send power to each block (but again the controlling two conventional Locomotives is confusing).  If you use the Rotary switch there should be included an "Off" position.  Another thought just crossed my mind.  If your pike is sufficiently large so that your blocks are large, this may make the operating of multiple conventional Locomotives somewhat easier.  So take this as something you might wish to think about as to how you run your railroad.  I hope some of this makes sense.

Yes

they need to be phased together.

as far as the block wiring

consider the actual linear footage of the track-then divide into equal sections.
it doesn’t matter if it’s yard or mainline-just try to get all the blocks equal in footage.
I would separate the blocks based on their primary use-yards independent of mainlines, Spurs separate from yards and mainlines.
good luck

My layout has 12 blocks each powered by its' own Lionel 180 brick transformer. This is overkill. The layout is only 16x17 feet and I probably could have gotten by with six or eight blocks and set up power districts where one transformer powers multiple blocks. But I'm mostly done with the 12-block setup so it stays as-is. I run DCS and TMCC through 3 MTH TIUs--no conventional or Legacy. 

My most recent chore has been phasing the transformers. I was thinking that since I was running "modern" transformers, they would all be in phase from the factory. Not so! Five of the 12 transformers were not in phase with the other seven and I had to grind the wide blade down on those so I could reverse the plugs. Just finished last night.

But I was surprised to find a phasing problem with the Lionel bricks.

Don Merz

Don,

The problem with inconsistent phasing across Lionel's production of the 180's is well known and has received many comments, across many threads here on the forum and elsewhere, since it was first noticed about 20 years ago.

It was such an issue that Lionel released a 'phasing adapter' (72-2983-251) years ago as a fix.

"Grinding of plugs", which renders the UL certification of the PH180 units useless among other things, is neither necessary nor safe.

Mike

There were problems with production of transformers from multiple manufacturers, the PowerHouse 135 had phasing issues as well, and do did some of the MTH Z bricks.  There are two wires, I guess it's just too easy to swap them in manufacturing!