Blocks & Stop Blocks

I use these on my layout. A block is just an electrical partition of the track. The power is usually on if you are running command (Legacy/TMCC or DCS or LionChief). If running conventional, you may want to use some kind of selector switch to choose between multiple throttles.

A stop block is a track segment that is controlled by an on/off switch, so you can kill power to it.

I think that's what you're referring to anyway.

Could you be referring to a wheel stop?

A simple way to think about blocks is how they apply to a large, simple oval.

You break that oval up into electrically isolated sections (blocks) so that a different power source can be used to power each block.

This then also allows you to completely cut the power to a given block. With conventional operation, that might be a siding where you park a train while another continues around the oval. 

Another definition of the stop block might be where one block of the oval is electrically tethered to another block of the oval (usually on opposite sides of the oval). When train 1 reaches the "dead" block, it sits there until train 2 arrives at a block that then electrically activates the block that train 1 is sitting in. 

If spaced correctly, and the train speeds and lengths are about the same, it can give the appearance of two trains chasing each other around the oval, starting and stopping automatically.

The old Lionel manuals from the 50's have this depicted in various forms. 

I still use blocks with on/off toggles, even with command control. No sense having the power draw of unused locomotives/passenger car lights when they are just sitting. The toggle lets me power down the siding. 

So if I am understanding this right running 2 trains at the same time you can have train #1 stop & let train #2 go by ?.

ROZY 205 posted:

So if I am understanding this right running 2 trains at the same time you can have train #1 stop & let train #2 go by ?.

Are you using a command control system?

While the example that I was describing above was just a simple loop with two trains following each other (but never one overtaking the other), that can be done as seen in my attached image. This is taken from a Lionel manual (1954 I believe) and it shows how using insulated block sections, lockons and 022 switches can give you automatic start-stops with two trains going in different directions.

In this diagram the stop block isolates both ground rails which will stop a train due to loss of power. It waits there until another train enters the control block. The wheels of the train pass the ground to the isolated rail which is connected to the ground rails of the stop block. This returns power to the stop block and the waiting train can then proceed. This is generally only used in conventional mode.