[ckissick]

I once worked the night shift (12:00-8:00) on a tunnel project. I was the project geologist. It was very surreal, being lowered, by a crane in, a "man-cage" down a 250-foot vertical shaft, and walking 600 feet to the tunnel face at 3 or 4 in the morning.

We were tunneling under a lake with 20 feet of gravel between us and the bottom of the lake. We injected chemical grout ahead of the tunnel face so the gravel wouldn't cave in. I would use my watch and record the setup time for a grout sample so we would know when its safe to dig, while muckers and jacklegs worked around me in deafening noise and the constant dripping of water on my hardhat. I loved it.