So, we've dug a (at least I think this is right) ~3.5 kilometer trench.
I dug 1x2 for the greater portion, and DE and I finished that. Then the crack kicked in and after admiring DE's railroad, widening the entire tunnel from 1x2 to like 5x5ish seemed like a good idea.
DE chunked out a ton, and with berlin airlift gravel deliveries, had a good portion ready for track to be laid.
So, while we were working on it last night, Infernal mentioned using TNT.
After seeing his setup, it's pretty brilliant. I knew all the dynamics of TNT, resistance factors, etc... but the way they are combined is awesome.
It's not a TON faster than 1 or 2 people working, and significantly slower than 3 or 4, but it is A BLAST (HAHAHAH PUNIC) One caveat to this is that 4x people working will collect ALL Of the dropped materials, so it requires more frequent depot runs for what will be a lot more material than we will need anytime soon (taking into account that most projects include the removal of a load of materials anyway). So that is a slow down. On the other hand, the TNT operation is pretty limited to a max of two people, one to tunnel the 2x1, and one to lay the TNT, which is pretty fast. Then you have to clear any low-resistance materials and replace them as you go.
Anyway, here is the gist:
Each TNT will blast a 3x3, assuming it is completely surrounded by either cobble, stone, or other blocks with similar resistance levels (i.e., not gravel, sand, glass, or dirt, for sure).
From the front, it would be:
XXX
XOX
XCX
O being the tunnel, X, the surrounding material to blast, and C being the cobble you lay down.
From the side (Just the "tunnel" down the middle of the 3x3):
T T T T TC
CCCCCCCCCCCCCCCCCCCCCC
So, you ignite the T(NT) on the far left, head on. The open space between TNT blocks is enough to ignite the next block in line, without moving it forward with the blast.
We used... 120 or so TNT to blast a 3x3 ~700 blocks, or .62 KM.
You lose a lot of the cobble, but whatever.
Anyway, great idea... the lrun1wf railway proceeds at a breakneck pace.
Anyway, HELL OF A LOT OF FUN, bottom line. Thank you Nick2, I owe you a stack of TNT for your awesome sulfur supply.