Compressed Air Drill Through Mountain
With a compressed air drill, you can dig through rock three times faster than with gunpowder or nitroglycerin. It would take you just about one year to complete a mile-long tunnel this way.

Learn more				Tunnel Score: 90

Here's how the drill works:

Compressed air is channeled into the drill, where it exerts pressure on a piston. The piston moves up and down with the change in pressure and delivers repeated blows to a drill bit. This vibrating drill bit tears through rock walls, making it possible to excavate large amounts of earth in short periods of time.

Today, tunnel diggers still use compressed air drills, from small hand-held devices to jumbo-size drilling rigs. But a big tunnel project like yours deserves the best technology available today. Try again!

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