Conceived in the early years of World War II as a plan to bury four fuel containers horizontally in a hillside at the U.S. Navy facility at Pearl Harbor, Hawaii, the Red Hill Underground Fuel Storage Facility ultimately encompassed the design and construction of 20 vertical storage tanks - each large enough to contain a 20-story building - buried in the volcanic hillside and connected by tunnels to a harbor-side pumping station more than two-and-a-half miles away.

Using existing rock as a construction shell, the project made use of innovative mining and construction methods that included building each tank from a central vertical shaft drilled 30 feet in diameter and removing all excavated rock through an elaborate system of conveyor belts specially made by the Goodrich Tire Company. Protecting more than 250 million gallons of fuel used by Navy fleets around the world, the Red Hill facility has operated virtually unchanged since its completion.

Facts  

• The entire Red Hill Underground Fuel Storage project includes a reinforced concrete fueling pier and an underground water-pumping station. 
• Construction on the Red Hill facility began the day after Christmas 1940. While the attack on Pearl Harbor on December 7, 1941, had little effect on the work site itself (which was mainly underground), the arrival of World War II in the Pacific did increase the demand for skilled laborers, especially welders, at the Pearl Harbor navy base. Nevertheless, work on the storage facility proceeded virtually without interruption. Work on the first tank was completed in September 1942, and the entire project was finished in September 1943, nine months ahead of schedule. 
• Each vertical storage tank is 100 feet in diameter and 250 feet high. Lined with quarter-inch steel plate, each reinforced-concrete tank was rigorously tested during construction for leaks and pre-stressed with high-pressure grouting between the tank and the surrounding rock wall. 
• While it required the labor of more than 3,900 workers in round-the-clock shifts to construct, the Red Hill facility is operated today by only four Navy staff members. 
• During Operation Desert Storm in 1991, Red Hill was used as a transfer point for fuel moving from the U.S. mainland to the Persian Gulf.