Assuming I’m of average size and strength, and I’m trying to tunnel through granite. I’m working alone, I have no explosives, and I try to dig for…say, six hours a day. How many cubic feet—or cubic inches, if the progress is going to be that slow—can I tunnel through per day?
(I wouldn’t say I need the answer fast, but…it’s information I’d like to have ready.)
It’s going to be pretty darn slow. I found a reference to a tunnel that was dug at a blazing speed of 9 inches per day. Unfortunately, while it did give the dimensions of the tunnel (roughly 25 feet wide and about the same height) it didn’t say how many men were working on it. It did however mention that air tools (introduced about halfway through the project) were five times faster. If you can find a good reference for air tools, just divide it by 5.
What hand tools do you have? A pick axe or a hand trowel? Do you have a means for sharpening or reshaping them as you go? Are you working under the hot sun or in a cool or shaded area? Will you have access to water (for drinking)?
I don’t know the exact answer but I do know it is incredibly slow. Somebody has to make the first climb for granite climbing walls and make the holes for the safety attachments for future climbers. I was told that it could take a whole day just to make a few of those in granite and maybe just one if the conditions are difficult. There is plenty of granite around here and it is a hard, dense rock. You can’t do very much quickly with it with just hand tools. There are lots of antique granite beams around here as well. I don’t like the thought of making even one of those and they aren’t even that big in the overall scheme of things.
I don’t know if you have access to granite of considerable size but I do. You can’t tunnel through it with hand tools in any reasonable amount of time. You can create stress fractures using hand tools to break it up and repeat and repeat until you die but your tools will wear out much more quickly than the rock will.
I’ve had some experience with drilling hard rock on Canadian Shield granite with a Gardner Denver 800 cfm (200 hp) compressor and drill rig using a 3 inch bit.
We would generally be able to drill 300 feet in 8 hours using percussion.
Percussion is somewhat like using a pick.
200 hp gives us 300 feet x 12 inches x 3.14 x 3 inches squared / 4 = 25,434 cu. inches chewed up in eight hours.
That is roughly 19,000 cubic inches chewed up in 6 hours.
Now I know that an athlete can put out 0.25 hp for short durations. At this point I’ll assume that you can put out something somewhat less, lets say 0.1 horsepower for 6 hours.
Therefore I’m figuring you might chip out 9 to 10 cubic inches.
This doesn’t explicitly answer your question, but might be of some interest: http://www.fhwa.dot.gov/environment/fspubs/84232602/page01.htm
I’ve actually talked to some people who do trail work in wilderness areas (where power equipment usually isn’t allowed) about this. Though they’re usually breaking big boulders that roll onto the trail into smaller movable chunks as opposed to boring through them, their experience agrees with “not much” being the answer. They have a lot of respect for the Chinese who did most of the work digging the railroad tunnels in the region by hand.
Fire-setting could be a useful trick. You’d need ventilation and fuel for the fires.
Yup, fire and water are the age old stone busting tools.
Big fire to heat the rocks, then splash with (preferably) ice cold water to crack the stone. Remove what cracks off, repeat process.
Some perspective on the question from the time (many moons ago) I worked on a government survey party out in the East Oregon Canyonlands…we often set corner munuments in very difficult rocky terrain. As these were legal land boundaries they had to be placed according to some very strict rules. If the corner landed on solid rock, we’d cement in a mushroom-shaped 3.5 inch brass marker with about a 4 inch stem, which was cemented into a hole in the stone. We’d drill the hole with a star drill and 3-lb. hammer. Usually took several hours to drill a +/- 6 inch hole, as the drill dulled down pretty quickly. I’ve read that the old miners usually carried a half-dozen or so drills in with them, changing them out as they got dull, then re-sharpened them all at the end of the day.
If the corner fell on fractured rock, or bedrock with a few inches of soil over it, the rules said we had to set a monument attached to a 3-inch by 30-inch-long pipe with flared end to hold it in place. This required a hole 24-30 inches deep by maybe 8-10 inches wide. The main tool was a steel bar about 2 inches around by 6 feet long. One end had a sharpened point, the other a flattened spade-shaped end. It probably weighed 15-20 lbs. Working in pairs, normal procedure was for one person to pound away with this thing until his tongue was dragging the ground, then the other would kneel and scoop out whatever loosened material was there with something like a tuna tin…shovels wouldn’t fit the hole.
An 8-inch hole 30 inches deep is about 0.4 cu. ft. of material, and I can recall a few times, in very difficult conditions, where two of us would spend 6 hours or more setting a monument. Of course, this included transporting the tools and ourselves to the site, as well as setting the post, which carried yet another set of exacting rules. So I suppose under ideal conditions two people could chip out about 1 cu. ft. of granite in a day…much more, of course, if they could break and pry out fractured chunks.
SS
With a diamond pickaxe, I can easily mine 300 granite blocks per minute, assuming I don’t get trapped by gravel or fall into lava.
Oh wait, this isn’t the Minecraft forum…n/m.
It also depends wildly on the type of rock. Granite is one of the heavier and denser materials that you could have picked; digging through the sedimentary stuff (sandstone and the like) isn’t half so bad.
I was able to dig thru about 10 albums before dinner once.
DAMN IT! You beat me to it. 
Ba-dump!
You’re not posting from prison are you?