H&H has been performing engineering services for the Baltimore Harbor Tunnel as part of our on-call contracts with the Maryland Transportation Authority (MDTA) for the over 10 years. Engineering services have included performing the biennial structural, mechanical and electrical inspection of the tunnel and ventilation buildings; troubleshooting of the tunnel ventilation fans and pump systems; designing fan and pump repairs; development of task order repairs, providing construction support and inspection services and developing the mechanical maintenance program for the fan and pump systems in accordance with the Tunnel Operations, Maintenance, Inspection, and Evaluation (TOMIE) Manual.

Most recently, we have performed the inspection of the tunnel ventilation fan and pump systems within the ventilation buildings in accordance with the new National Tunnel Inspection Standards (NTIS).

The Baltimore Harbor Tunnel was opened to traffic in November 1957. The four-lane tunnel is owned and operated by the Maryland Transportation Authority. The tunnel is nearly 1.4-miles long crossing under the Patapsco River and has an annual traffic volume of 27.6 million vehicles.