1.42 3x3 tunnel with torches

This program was made for making better tunnels. I felt little bit claustrofobic in that 3*2 tunnels. Even without torches that tunnel may become unwanted monsterspawner.
So I've made 3*3 tunnel like railcraft boring machine do. In addition, you put torches in first slot and some solid (non gravity effected) block to second slot and turtle place every 5 blocks torch on left side block. This program is durable I think. I have tried gravel falling and code can handle that in most cases. Thanks for direwolf20's loops tutorial.

EDIT: so now when you put chest behind your turtle, automatic trash is happening :P/>/> So no more blocks on the floor

Code: http://pastebin.com/W1Fgtp8T (v.3.0 23.9.2012 - gravel don't cause problems anymore)

Old code 1.0 (without chest trash system): http://pastebin.com/yTyi9B48
Old code 2.0 (with trash system but gravel may cause problems): http://pastebin.com/yv3Ye2VY

Spoiler

Please post suggestions, bugs and other.

I tried this out just now and it sort of turns left and instant breaks blocks but does not keep going from there. I tried coal torches and stone then I tried torches stone and coal in the order you said and nothing seems to care it just locks up :P/>/>

This is epic :D/>/> just what i was looking for,only problem is when it runs out of fuel it just stops and i have to reset my turtle and my home chest :P/>/> so maybe could you add auto refueling and takes coal out of chest so it keeps going thx

Hello! I have written a similar program today… It is not finished yet - it doesn't handle inventory overflow for now. It also places torches, AND fixes the walls, floor and ceiling, if there are any holes. If it can't move or place block because of any entity, it attacks that entity (It have killed a creeper and two zombies for me :)/>/>')
If you don't mind, I can post the code here.