S9: New York's Topography Challenges
Video duration: 1:38
Construction on New York's underground rail system began in 1900 with William Barclay Parsons as the projects chief engineer. The city's topography presented a special engineering challenge for Parsons and his team. With many dips, valleys, patches of quicksand and above-ground infrastructure to take into account, digging underneath Manhattan became a monumental task.