Bus wire vs terminal block

Bus wiring is fine for conventional and Lionel TMCC/Legacy.

A terminal block for track power comes in handy for MTH DCS where it "prefers" a star wiring method. I.e. all of the track feeders go out from a central location and are of similar lengths.

You can howver, use them as you like other ways.Say if you had an area with alot of accessories or buildings and you ran power from your transformer to the distribution block and ran wires out of the block to the buildings and accessories.

As for track power, the objective is to minimize voltage loss due to track and wire internal resistance.  This is accomplished by feeding the track at multiple points.  Some "rules of thumb" are out there on track intervals between feed points.  I'm not an advocate of any particular one.

On my layout-under-construction, each benchwork segment is no more than 8 feet and I have track feeders in each such segment.  The 2-track main line is divided into 4 blocks, any or all of which may be disconnected via toggle switches, primarily for safety and troubleshooting purposes.  So, for each of the two main line tracks, there are two division points for track power, (a) the feed from the power brick to the "block" toggle switches and (b) the point where the block feeder branches off to the benchwork feeders of that block.

The "drops" from track through tabletop are #16 AWG and the feeders from each block's feed point are #14 AWG.  Some might opine that this is excessive, but I had the wire sitting on a workshop shelf and, as noted above, the objective is to minimize residual resistance from power source to locomotive.  Note that each main track has completely independent "hot" (center rail) and "common" wires (outer rails).  I did not use a single "common" for both main lines.  If I did that, it would be #12 AWG, to minimize loss when two locomotives, on each of the mains, are within the same block area.  (In retrospect, I could have saved time & materials by doing that - and I had a roll of #12AWG wire on hand.)

I implemented all connections using barrier terminal strips and spade lugs, which is probably the most time-consuming way of doing it.  I did that in order to facilitate layout disassembly at some point in the future.  6-position (2-track main) or 3-position (single track) barrier strips connect the track drops to the benchwork section feeders, which terminate and are fed from one such barrier strip within each track block section.

There are a number of alternative means of connecting track drops, such as the Scotch insulation-displacement connectors that do not require any wire cutting and stripping and the lever-and-cam branch blocks used by Gun Runner John.  Some of these facilitate disassembly/rework and some don't.

On the turnout and accessories front, #16 wire should be OK.  I used #18 multiconductor to connect my turnouts (DZ-2500 motors) and will likely use #16 for accessories, whenever I get started on that phase.

There are many equally-valid methods of power wiring, just keep in mind the overriding principle of minimizing wire and track resistance.

All other things being equal, it's a matter of personal preference to me, unless you need to wire for DCS, where using a distribution block can be helpful. Either method will get the job done, which is to provide a source of transformer power from which you can connect feeder wires to various and remote locations of your layout so you maintain good voltage throughout the layout and do not experience power losses.

When using bus wires, the issue always comes up about how to make the connection between the bus wire and the feeder wires (power drops) going to your track. There are various methods and types of connectors (suitcase, t-taps, levers, etc).

Using a distribution block, you simply connect your transformer to the distribution block red and black input terminals using crimp-on, U-spade connectors (you can also use banana plugs) and then run paired wires out from each output terminal on the distribution block to wherever you need to make a power drop to your track. Personally, I think that's easier and less complicated.

A couple of points:

1. I use 14 gauge wire from transformer to the distribution block and 14 gauge wire from each output terminal on the block to the power feed locations around the layout but, rather than connect the wires directly to the track, I mount a 2-terminal block on the underside of the layout where the power feed will go and connect the 14 gauge wires from the distribution block to one side of each terminal block and then run 16 gauge wire the 10" or so from the other side of the terminal block to the track. I find it easier to work with the 16 gauge wire when making the track connection.

2. Distribution blocks from MTH (and others) come with either 12 or 24 terminals, depending on how many power drops you need to make on your layout. You can also "piggy back" the blocks if need be.

3. If you're running command at a constant 18 volts, you can also connect 18 volt accessories to the same distribution block or you can use a separate distribution block for just accessories. For instance, I run wires from the 14 volt tap on my Z4000 transformer to a separate distribution block and then run paired wires out to all my accessories that run on 14acv.

4. Most of the distribution blocks come with a pre-printed sheet where you can write down and keep track of which output terminals go where or you could make your own.

5. I also use the two terminal feeder connection blocks as a location to solder on additional TVS suppressors.

I use two 12 gauge buses, one hot, one common. Drops are 20 gauge, soldered to bus and track. I used one terminal block at one transformer to separate different kinds of accessories because I had a problem I needed to chase down (it was the transformer itself).

Thanks for all of your help.  I think I will go with the bus wires for the track and then terminal for turnouts and accessories.

For what it's worth - I am wiring up in a similar fashion to what my grandfather had started on his old table.

I have a large 12 gauge (common/"U" terminal/outer rail) buss wire running around the table directly under the mainlines (more or less) and then for all the "hots" or middle rails I use 12 gauge to supply terminal/distro blocks and then 16 gauge for the outputs of the terminal/distribution/star to the track blocks.

Both work.  The terminal blocks look neater, more organized.  I use a combination.  My positive feed with the DCS go through terminal blocks.  All my negative wires are in a buss wire.  Works perfectly.  1400 square foor basement layout.

My layout is completely bus wired and I run TMCC/Legacy and also DCS (passively).

You don't need home run wiring to be successful with DCS.