The twin tunnels, each 4,200 ft long and having a 39 ft inner diameter each, were dug out and constructed under the government cut at Biscayenne bay. They each were fitted with two traffic lanes, curbs, walkways, ventilation fans and additional safety features. The bottom of the tunnels is approximately 120 ft below the surface of water. The tunnel boring machine was longer than a football field at 540 feet (160 m) long, and over 40 feet (12 m) in diameter. It was used to bore two side by side 43 feet (13 m) diameter tunnels, one for each direction, each 3,900 feet (1.1 km) long. The tunnel boring machine itself cost $45 million and was custom built for the Port of Miami Tunnel Project by the German firm Herrenknecht. Both tunnels were ready by May 2013, followed by work on road widening on tthe MacArthur Causeway and other remaining works. The PortMiami tunnel was opened to public on August 3rd 2014, slightly delayed from the promised date of delivery due to minor mechanical fixes required, for which the main contractor Bouygues was fined $115 thousand for every day that the tunnel was not open, losing millions of dollars. The tunnel’s dedication and subsequent opening to traffic mark the completion of one of the most expensive and elaborate transportation projects in South Florida history.