TBM Big Alma Launches, Commencing Construction of Second Central Subway Tunnel
Tunnel boring machine Big Alma, shown here on the right, began tunneling under 4th Street. On the left is the entrance to the parallel tunnel being built by TBM Mom Chung. There are now two 350-foot-long, 750-ton tunnel boring machines mining under 4th Street to construct the Central Subway’s pair of parallel tunnels. Our second […]