Sand Pit Video

Very Cool!   This was sent in by Tiny.  I love it, it is a great video.  I have to watch it again to figure out how everything works. Thank you.
To see the video click here:

I looked up the track plan, here it is:

  I was fascinated with this and for some reason reminded me of a toy I bought years ago.  It was called "Thomas Big Loader" and it was an engineering wonder to watch as it perpetually moved 'rocks' around the display and back to refill itself.