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About Red Hill

When Pearl Harbor was attacked on Dec. 7, 1941, enemy planes failed to destroy vital American fuel reserves, a failure that would have consequences in the early months of World War II. The U.S. Navy was aware of the vulnerability of above-the-ground fuel tanks, so construction was already underway for a one-of-a-kind fuel facility deep within the basalt rock of nearby Red Hill. Today, the Red Hill Bulk Fuel Facility can operate without external power, is physically protected and cyber-hardened and is critical infrastructure for the nation's defense. The 20 tanks within Red Hill, are steel-lined concrete up to four feet thick, including a layer of gunite, and can store millions of gallons of jet or marine fuel used by the U.S. Air Force, Army, Marines, Navy, Coast Guard and Hawaii National Guard. In January 2014, Tank 5 experienced a release of 27,000 gallons of fuel due to a contractor's error and an ineffective response and oversight. After that one-time extreme release, the Navy and Defense Logistics Agency intensified modernization of the facility and monitoring of groundwater and drinking water. The Navy continues to work with Environmental Protection Agency and Hawaii Department of Health regulators under an Administrative Order on Consent to improve the facility and protect the environment .From 2006-2022, DOD invested $260 million in Red Hill for modernization in oversight, technology, operating procedures and protecting the environment.   On March 7, 2022, Secretary of Defense Lloyd J. Austin III announced the decision to defuel and permanently close the Red Hill Bulk Fuel Storage Facility.  Since defueling the facility, the Department of Defense and Navy continue to work closely with the Hawaii Department of Health and the U.S. Environmental Protection Agency and other regulators on the safe and expeditious permanent closure of the facility.  The Navy has also committed to environmental remediation of the site.

Before the United States entered World War II, the Roosevelt Administration became concerned about the vulnerability of the many above-ground fuel storage tanks at Pearl Harbor. In 1940 it decided to build a new underground facility that would store more fuel and be safe from an enemy aerial attack.


The Red Hill site would provide unprecedented flow rates of fuel due to its elevation. In addition, the site's unique geological characteristics, including basalt rock, could support such large tanks. Federal, local government and contracted engineers and geologists performed many surveys of the Koolau Range and eventually reached a consensus on Red Hill as the best choice because it is mostly regular basalt.

Their original plan was to build four large underground tanks. These would be horizontal, as all underground tanks were at the time. However, during the planning process, the engineers decided to build the tanks vertically because construction and excavation could occur simultaneously. This was possible because a vertical shaft drilled through the centerline of the tank would allow excavated rock to funnel down onto a series of conveyor belts in the lower access tunnel.

Planners and engineers began the process by acquiring the real estate, staging equipment and materials, and building a work camp. The 3,900 workers worked around the clock, seven days a week, to complete the project. Construction started by excavating the vertical shafts for all 20 tanks concurrently with mining of the upper access and lower access tunnels. The tunnels were aligned directly in the middle of the parallel rows of shafts. Once perpendicular to the shafts, cross tunnels were mined to connect the shafts to the main access tunnels.

For constructability and safety reasons (cave-ins), the upper domes needed to be built first, so the miners excavated individual ring tunnels around the circumference of each of the future upper dome bases. They then scoped out the area of the domes and proceeded to construct the steel framing, steel liner and rebar. Workers continuously poured concrete that ranged in thickness from two feet at the crown to eight feet at the base. Once the concrete cured, it was pre-stressed by pressure grouting the area between the concrete and the basalt.

Red Hill construction, 1941

Upon completion of the excavation, workers erected a steel tower in the center to the full height of 250 feet. The tower served to support concrete chutes, pipes, booms, and other equipment necessary to install the piping, concrete, and steel linings. Workers then began to erect the steel liner and rebar incrementally so that they could pour concrete in stages. Concrete was poured continually and workers had to remove wooden shoring as concrete filled. They injected pressurized grout to pre-stress the concrete by filling void space between the concrete and the gunite. When finished, the tanks were tested by slowly filling them with water while laborers in boats physically checked the entire surface area of the steel liner.

The Japanese attack on Pearl Harbor took place during the construction of Red Hill. As a result, a portion of the site was used to bury a large number of the fatalities. Those not claimed by families were moved to the National Memorial Cemetery of the Pacific when it opened after the war.

The Department of Defense has spent more than $200 million on continual technological modernization and environmental testing at Red Hill since 2006. The facility monitors the fuel level in each tank to one sixteenth of an inch and controls the movement of fuel throughout the facility. If a tank level decreases by as little as half an inch, alarms will sound in Red Hill's control room, which is continuously staffed.


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