FILE - In this Feb. 3, 2010 file photo, a sand hog works inside the massive cavern for the new 34th Street Station in New York that was carved out by giant tunnel boring machines. On Monday, July 23, 2012 the last of the 200-ton tunnel boring machines finished its mission digging 13 miles of new train tubes deep beneath New York City. The seven machine fleet bored through bedrock and created 16 new tunnels in 4 ½ years of digging. (AP Photo/Mary Altaffer, File)