Hi Mick,
Stop thinking of how to signal a layout. Erase everything you ever knew or read about signaling. Forget everything!
Now, all Auran did was let us signal one section of track. This piece of track may be 3 miles long or 10 miles long. SO WHAT! It doesn't matter, just plop one signal down and you have what Auran calls a block. It's that simple. I'm not kiddin'. (It's really two blocks with one signal, the track before the signal and the track after the signal would be two blocks.)
Take this 3 miles of track and plop 3 signals down and you now have 4 blocks.
That's all there is to