10,000 Year Clock Update

We just completed the 12½ 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.


From Stewart Brand