Here in San Diego especially, there has been quite a bit of publicity w/regard to a pair of recently discovered tunnels for moving drugs across the border. In both cases the tunnels were almost a half mile long, with electricity, ventilation and tracks for moving tons of marijuana. In some places they are 60’ below the surface. Both started in homes in Tijuana and terminated in warehouses here in the U. S.
With all that’s been said, not a word as to how they were dug, with what type of equipment and over how much time. Considering all of the above as well as the amount of material that had to be removed, the digging/construction had to be significant.
I understand that it typically happens over a long time with small amounts being moved with each pass. That is the traditional method (as in jail breaks, vault break-ins, et. al.)
However, this kind of scale may not apply to what you described.
One news story this morning (Maybe linked in News.Google.com or msnbc.com.) mentioned electricity for jack hammers. The story did not reveal anything else interesting.
This reminds me of Jesse Pomeroy, who spent 40 years in solitary confinment (in the late 1800s). One time he dug his way out, using only toothpicks and other small things he found. It took him about 18 months to do this.
He walked under his cell and out into the main area, and found himself still in the cell block unable to go farther. So he just walked over and said “Hello” to the guard. When asked why he did it, he said, “What else did I have to do?”
I have an X-great grandfather who escaped from Andersonville in the US Civil war — twice. Reading about escapes is fun, especially if you wouldn’t exist, unless they were successful. It’s probably best to not dwell on how unlikely the escape was. Just stick to the fact that you wouldn’t exist, unless it had succeeded… Ummm… OK, it succeeded… Umm… What if it didn’t…? Umm… Let’s not go there… Or I might cease to exist…
Have you ever been to a border town? Notice how many chess sets they have there? Chess set with nicely carved stone figurines?
The man likes to play chess; let’s get him some rocks.
These tunnels are getting massive amounts of investment to get them done quickly and quietly. It isn’t just a bunch of rednecks with a crazy idea. They have the money to hire competent engineers. Even if the tunnel only stays in business a week or two the value of the product on the us market will cover the cost.
That said, even with limited resources getting a tunnel to start and end where you want it doesn’t require high tech. A compass and a tape measure will get you where you want. Throw in a laser pointer and a level and it’s a breeze.
A laser pointer can insure that the tunnel is a straight line. But if your aim is just a half-degree in the wrong direction, the end of the tunnel will be very far from where you expect.
Yep. The technology needed to make the tunnel the right length, direction, and straightness is relatively old. Any surveyor from the last century could do it.
A recent article mentions such a tunnel that was a half-mile long. Let’s keep it simple and work with one which is even shorter – a half-kilometer.
Let’s say that the tunnel goes in a direction just one degree off of where you intended. The sine of 1 degree is .017452, so the far end of the tunnel would be off by 0.5 * .017452 km, which comes to .008726 km, or 8.7 meters.
So a half-mile tunnel that was off by one degree could end up 30-35 feet off target.
*Hilts: Hold on to yourself, Bartlett. You’re twenty feet short.
Bartlett: What do you mean, twenty feet short?
Hilts: You’re twenty feet short of the woods. The hole is right here in open. The guard is between us and the lights. *[right]-- The Great Escape[/right]
I imagine that they’re dug using hand tools and timber supports. If you’re digging in a somewhat stiff clay it’s not really that big of a deal at all. Most of the load is transfered to the existing soil mass through arching. In fact, at 60’, the clay doesn’t even have to be all that stiff for the face of the tunnel to be stable.
Sand, especially below the water table, would be more difficult. Rock would be harder to tunnel through, but safer. Although they don’t have OSHA, so who knows what the actual techniques are.
“So, SanDiegoTim, how do you feel about the answers to your OP? Can you dig it?”
Entertaining, but I’d still like the particulars. I don’t think it an oversight that nothing has been said about it. I’m not a black helicopter guy, but I also think it interesting the media hasn’t inquired. Or if they have, they’ve agreed to not publish.