New York City under-river tunnel assessment and rehabilitation

New York City, New York

State-of-the-art technology efficiently assesses damage, reveals repair requirements


•    Scanning technology efficiently reveals flood damage, repair needs
•    Rehabilitation proceeds more quickly, reducing time tunnels are closed 

HNTB was selected to investigate near- or potentially long-term damage to rail and structural systems in several under-river New York City Transit Authority tunnels and Amtrak tunnels. The structures were among those flooded with seawater during Superstorm Sandy. 

The thorough investigation involved a detailed survey of the tunnels using state-of-the-art, three-channel scanning. Those processes yielded photogramatic, laser and infrared scans, which allowed HNTB to develop timely recommendations for how each structure should be repaired and rehabilitated. 

The technology enabled the team to complete the assessments efficiently and safely, thus leading to quicker repairs and reducing the amount of time each tunnel was closed to traffic.