SF launches first Central Subway drilling machine

May 30, 2013 10:15:58 AM PDT
San Francisco Mayor Ed Lee is celebrating the Thursday launch of the first tunnel boring machine as part of the city's Central Subway project.

The first pieces of the gigantic machines arrived five weeks ago and workers have been putting the huge parts together ever since.

Once they start, the 400-ton, 300-foot long drilling machines will bore a pair of tunnels running 1.5 miles long from the South of Market area into Chinatown.