The 43-foot wide, four story cutting head of a tunnel boring machine was lowered into the hole that will be its Miami home for the next few years as it digs the Port of Miami Tunnel.
Drilling has begun on a $1 billion tunnel project to connect the Port of Miami with nearby expressways.
Miami Access Tunnel officials tell The Miami Herald that work began early Friday as a massive drill broke through a concrete wall lining a pit on Watson Island off downtown Miami.
Officials say that by Monday evening, the machine had drilled about 20 feet into the earth. Some fine-tuning and final testing are scheduled this week. The drill is scheduled to emerge at the port in six months.
The drill will build the tunnel's walls as it digs. The machine has been nicknamed ``Harriet.''
Once it reaches the port, the drill will be turned around so it can dig a return tunnel. The tunnels are scheduled to open in May 2014.