Talk:Turtles/@comment-67.249.216.188-20120821013448/@comment-5394278-20120821020950

You can pump items out from its starting point that it returns to with buildcraft pipes, then send a redstone signal to a console with a modem (assuming the mining turtle is wireless), and write a program to have it send a turtle.go down 200 then a turtle.excavate (however wide your pit is). That would be the best automation they're capable of.