The World’s Largest Drill Bit?
The 42-inch water main that carries water from the reservoirs into downtown San Francisco runs underneath our house. SFPUC is replacing it with a new one that doesn’t go underneath our house, and they are drilling a tunnel through Bernal Hill for the new pipe. A couple months ago they started digging a giant hole at the top of the street, which now goes down three or four stories. They call this the tunnelhead.
Recently, this weird equipment appeared next to the giant hole:
On the other side of this thing is an opening with a chair that you can sit in:
Here is a close up of the knobby bits:
Does anyone know what this thing is? Is it the world’s largest drill bit???
There isn’t a lot of information about the “Bernal Heights Water Pipeline Tunneling Project” on sfwater.org, but there is this map of the reservoirs and pipelines.
Filed under: san francisco |
3 Comments
Tagged: bernal
http://www.technovelgy.com/ct/Science-Fiction-News.asp?NewsNum=83
another big honkin drill bit
Tom sends this:
the world´s biggest drills are Tizona and Dulcinea 15 m.Ø
they have just finished work in Madrid, Spain.
http://en.wikipedia.org/wiki/Tunnel_boring_machine
http://www.tuv.es/es/es/noticias/news26.php
http://www.madridiario.es/mdo/actual/canales/distritos/archivo/arganzuela/tizona-210206.php