869 feet of tunnel, dug by hand, 30 to 90 feet underground, through one of the most surveilled patches of earth on the planet. Run the engineering on that and it stops looking like crime and starts looking like a mid-size infrastructure project.Start with the dirt. To go 869 feet you excavate on the order of 1,000 cubic yards of soil, every shovel-load of it hauled out through the same narrow shaft you climbed in through. No dump trucks, no spoil piles, because a spoil pile is the one thing a su