Year Inducted: 1989
When construction began on December 29, 1938, the Bankhead Tunnel was the first engineering feat of its kind in the deep South. The $4 million tunnel was built by the city of Mobile to improve traffic flow on U.S. Highway 90, one of the most heavily traveled highways in the country.
In 1938 the plans for a tunnel that would connect Government Street and the Cochrane Causeway on the southern tip of Blakely Island were presented to the Mobile City Commission by Wayne F. Palmer of the firm of Wilberding & Palmer. With support from Palmer, the city commissioners and Alabama Senators John H. Bankhead and Lister Hill, financing for the project was arranged through the Public Works Administration without any lien on the ad valorem taxes of the city.
The Bankhead Tunnel was built using the trench method. The 2,000–foot steel and concrete tube was, for the most part, built above ground in seven sections, each of which was sunk into position in a dredged trench cut across the river’s bed. The tunnel’s seven sections of tube are 298 feet long and 30 feet in diameter within an exterior octagonal shell.
The top of the tube section is at a maximum of 47 feet below the water level. The landward approach sections of the tunnel are built of concrete and structural steel, and are as much as 45 feet below the level of the river waters.
The control center was established on Blakely Island.
From this center, the operator controls lights, pumps, ventilation, fire, and police alarms from the master switchboard. Three of the largest blower fans ever built provide ventilation, putting fresh air into the tunnel every two minutes.
Water–tight floodgates are located on the Blakely Island portal to seal out trouble in the case that high water ever presents a problem. The tunnel is provided with 24- hour police protection for both the protection of the people traveling the tunnel, as well as the tunnel system.
Although built primarily for the flow of motorized traffic, electric power and communication lines also run through the tunnel walls.
The tunnel was built in 22 months, which breaks all records for rapidity of construction for work of this type, and was done so with low cost and without the sacrifice of any element of quality. The Bankhead Tunnel opened for travel on February 20, 1941, ushering in a new chapter in the art of construction of subaqueous vehicular tunnels.
Because of its historic significance, the tunnel was targeted for beautification by the Keep Mobile Beautiful Committee. In cooperation with the Alabama Highway Department, the project is slated for completion in the summer of 1989.
