To Block or Not

It can greatly simplify locating and fixing a problem.  Gremlins are inevitable!

Good point, David.  The next question in sequence becomes whether to switch power from a central point to each block or to use local relays to enable/disable, assuming a common source (e.g., one power brick per main line track).

If you will not be running conventional but only command engines, wouldn't the easier solution be to switch power centrally, and avoid fooling with relays?

Back to your original question, blocks are also useful for sidings, so you do not burn out all of the bulbs in your passenger cars, or unnecessarily expose idle engines to spikes in power from a main line derailment or short, for example.

@KarlDL posted:

Good point, David.  The next question in sequence becomes whether to switch power from a central point to each block or to use local relays to enable/disable, assuming a common source (e.g., one power brick per main line track).

That might depend on the size of the layout.  I probably could run my mainline with 1 or 2 bricks, but power districts help in the running of multiple trains that might otherwise overload a single block.  How big is your layout?  How many engines do you plan to run?   How many conventionally lighted passenger cars?

George

G3750, I'm not likely to run more than 2 mainline trains (2-track mainline) and one yard switching job at a time.  The layout fills a 2-car+ garage bay and will have nearly 300 feet of track.  To the extent that my passenger cars aren't LED-lighted, I will convert them over the year.  I'll likely use blocks for tracks that trains will be stopped on for significant time (e.g., passenger station secondary tracks, yard tracks, engine servicing) and safety where access bridges exist.  I don't foresee running two trains on a given main track very often, but will size the power sources accordingly.

David98, using relays facilitates multiple locations for power control, such as at the central power panel and locally near the block, with low-current wiring.

I would design blocks into my layout, but I don't have to power all the blocks independently to start with. For example, if I had 40' oval, I could lay the track creating four 10' long blocks, and drop a power feed or two from each block to below the table - then run one power wire from transformer to all the feeds - looks like a single block. Later in time, I could now decide to wire some of the blocks independently, as the track work with feeds is already done.

You MUST use blocks so you can quickly locate shorts or problems. It is inexpensive to power each block with it's own source so that is what I did. As the guys hinted above with their comments about running passenger trains, it takes very few trains to overtax ANY transformer. Each block with it's own power prevents transformer meltdown. How many blocks? I think Barry in his DCS book suggests a limit of 90 feet of track per block. If I have that right then, with your layout at 300 feet, that leaves you with 3-4 blocks.

So, if I may suggest this, you can buy one DCS TIU, 3-4 Lionel 180W bricks and run your TMCC through the TIU with either the DCS remote or a smart phone and DCS WIUs (I think one WIU is required per block, but I don't do smart phone control so I don't know). Run your accessories and structure lights on an old ZW or modern Z-4000.

This rig will give you a pretty inexpensive, very capable command control layout on which 2, 3 or 4 trains will run with no issues.

Good luck!

Don