I'm pretty sure Tmcc blocks are more about separation of of additional transformers/ bricks, than being there for signal reasons like with dts. With Tmcc the feeds don't HAVE to be blocks, but can be drops instead. A drop off a bus still delivers power easier than rails alone can. Plain and simple, the more drops the less voltage drop, which is good.
Actually. This wiring isn't really 'blocks' to me because it's from one source. It's a bus and drops to equalized isolated branches, but I roll with it
DC's likes equal branches I guess. Tmcc doesn't usually, if ever, suffer from it that I've heard of, so why not? I often build with "if" in mind.
IMO The only reason to differ would be focused more on conventional running alternative, where I like to add power drops in the curves because that's where they slow down and a good feed really helps. But Dave's second grouping actually looks pretty good for both dts & conventional both. The Tmcc is less concerned and just wants it's unbroken track path and signal airspace around it.
My use of the term "block" simply suggests that the design be divided into segments with individual power runs to each of those segments. It doesn't mean the segments have to be isolated like you'd do with conventional block control wiring.
DCS doesn't require equal "branches", but it does seem to work best when both wires from the transformer or terminal strip are the same length. This suggests not using bus wiring, but there are people who do and have no problems. DCS also likes the center rail to be isolated between "blocks".
Like I said, I don't know TMCC or the "airspace" around it, but I think you're suggesting that no matter how the layout is wired, he may still have signal issues in and near the tunnel because of the chicken wire used for the tunnel, it seems to be affecting that "airspace" you mentioned.
My 1st example was just to show how a terminal strips fits in. I divided the layout into several color-coded segments, but I didn't run lines from the terminal strip to each of those segments. My 2nd example was just to show how a single "bus" would run around the layout and have multiple drops to various points. I also color-coded segments, but only as an illustration.
From what I gather, TMCC doesn't been "blocks", so the colors can be ignored in both examples and the layout considered one big "block" with terminal runs or drops spread around the layout. I think Flemming is looking for specific than just general explanations of wiring schemes. If it were my layout, I'd use the first approach with a terminal strip located in the center of the layout and runs something like this. Again, the colors are just for illustration purposes. I would probably add another run for the spur.