The Long Now Foundation breaks ground
Jan. 24th, 2012 12:13 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png)
"We just completed the 12 -- foot diameter, 500 foot deep vertical shaft for the 10,000 Year Clock."
We used a mining technique called raise boring. Take a look at the video -- it's an interesting operation. Instead of drilling down from the top, you pull a large diameter reamer up to the surface from the bottom using a smaller diameter pilot hole -- more efficient than a top-down drill because the rubble isn't fighting gravity. It rains down beneath the advancing bore and gets hauled out a horizontal shaft at the bottom. Our next major step will be cutting the spiral stairway using a robotic stone cutting saw. In parallel, we're also manufacturing and testing the Clock components.