As part of a four year On-Call Contract to provide architectural, mechanical and electrical engineering services, Hardesty & Hanover completed the preliminary investigation and report for ventilation fan equipment in the Fort McHenry Tunnel (FMT) east ventilation building. Two supply fans and one exhaust fan were reported by FMT maintenance to be making irregular noises during operation. Hardesty & Hanover structural and mechanical engineering personnel responded on an emergency basis to perform the investigation and to develop the report with recommendations for immediate and long term repair options. The investigation included nondestructive testing and measurements of the fan machinery including: velocity measurements; displacement measurements; acceleration measurements; temperature measurements; oil sample analysis from roller bearings; feeler gauge measurements between rollers and races within roller bearings; and visual examination of roller bearings.

Hardesty & Hanover was tasked with, and has completed, preparing contract documents for in-kind replacement of the deteriorated roller bearings.

Hardesty & Hanover was requested to submit a fee proposal for the re-design of the roller bearing and shaft elements of the ventilation fans to provide a long term solution to the recurring bearing and shaft failure concerns. The proposal is currently under evaluation by the Maryland Transportation Authority.