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September 11, 1941: Pentagon Construction Begins

09/11/2006 8:15 AM

Today marks the sixty-fifth anniversary of the start of construction on the Pentagon, headquarters of the U.S. Department of Defense (DOD) and the largest office building in the world. Located in Arlington, Virginia, the Pentagon sits atop 29 acres, stands 77.3 feet tall, and has a volume of 77 million cubic feet. Faced in white limestone, the building is made largely of concrete, a testament to its construction during World War II when metal was scarce. With a floor area of 6.5 million square feet, the Pentagon includes 17.5 miles of corridors, but takes less than seven minutes to walk across. Like spokes in a wheel, ten corridors run from a five-acre, central courtyard through five concentric pentagons which, despite their shape, are called rings. These individual pentagons or rings house over 23,000 military and civilian employees and are separated by interior courtyards that provide light to offices, cafeterias, dining rooms and shops. Today, elevators connect the Pentagon's five floors.

During the summer of 1941, President Franklin D. Roosevelt ordered the Department of War, the predecessor to the DOD, to address its shortage of office space. Some 24,000 military and civilian personnel worked in 17 buildings scattered across the District of Columbia. By the beginning of 1942, staffing levels were expected to increase to 30,000. Although the military considered the construction of temporary facilities, Gen. Brehon B. Somervell had grander plans. On Thursday, July 17, 1941, the head of the Army Quartermaster Corps' Construction Division ordered Lt. Col. Hugh J. Casey to design a 4 million sq. ft. office building - and to have the plans on his desk by Monday morning. The proposed location, a 200-acre tract of Virginia farmland, was bordered by five roads. With help from George H. Bergstrom, a prominent civilian architect, Casey met his deadline and delivered a plan for a massive, five-sided, air-conditioned building. The Secretary of War approved the design and Congress appropriated $35 million. Plans for the Pentagon changed during August of 1941. To protect the view between Arlington National Cemetery and the Lincoln Memorial, the site was moved to a swampy lowland near the Memorial Bridge. Construction began on September 11, 1941. First, crews moved 6 million cubic yards of fill onto the site and sunk over 41,000 concrete piles to stabilize the foundation. Workers then dredged 680,000 tons of sand and gravel from the nearby Potomac River and produced 435,000 cubic yards of concrete. Although the Pentagon's original plans called for two floors, the Department of War more than doubled the building's height after the Japanese attack on Pearl Harbor on December 7, 1941. Under the leadership of Gen. Leslie Groves, a veteran of the Army Corps of Engineers who would later head the Manhattan Project, three crews of 4,000 worked around the clock to finish a building with five floors. At times, construction of the Pentagon outpaced planning.

To conserve metal for the war effort, architects designed concrete ramps instead of elevators and workers laid concrete drainpipes instead of metal ones. Bronze doors, copper ornaments, and metal toilet partitions were absent from the Pentagon's design. In April 1942, the first occupants moved into the building even though the grounds and exterior were incomplete. Construction was finished in time for a dedication ceremony on January 15, 1943. Overall, the project lasted 16 months and cost approximately $83,000. At its height, the Pentagon housed as many as 33,000 people. Although 10,000 fewer employees work there today, the building's specifications remain impressive. Today, the Pentagon contains 131 stairways, 13 elevators, 19 escalators, and 7,754 windows; 7,000 electric clock outlets, 691 drinking fountains, and 284 restrooms; and 16, 250 light fixtures, for which 250 light bulbs must be replaced each day.

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