In everyday usage, “The Pentagon” is shorthand for the U.S. military command, so we sometimes forget that it is an actual building. Last week’s terrorist attacks on the U.S. reminded us all too forcefully that it is, in fact, really just an office building–albeit one of the largest in the world, one in which 23,000 military and civilian employees work every day.
The Pentagon was was conceived at the request of Brigadier General Brehon B. Sommervell, Chief of the Construction Division of the Office of the Quartermaster General, on a weekend in mid-July, 1941, to address a critical shortage of office space for the War Department.
The groundbreaking ceremony took place on September 11, 1941 (60 years to the day prior to last week’s attack). It was built in just 16 months, with each “wedge” of the five-sided building being occupied as it was completed, and was dedicated on January 15, 1943.
The Pentagon is built on a 583-acre plot of land. Each side of the five-sided building is 921 feet long, which is why the building itself covers 29 acres; the center court alone, which looks rather cozy in the familiar aerial photographs of the building, is actually five acres in size. There are 67 acres of parking lots, 6,636,360 square feet of floor area, 284 rest rooms, 691 drinking fountains, 7.1 acres of glass in the windows…the list of impressive numbers goes on and on.
The five-sided design of the building, which seems at first glance highly symbolic–many fortresses have been pentagonal–was actually more or less accidental. The original site for the building was a tract of land known as Arlington Farms, which was bordered by five-roadways, giving it a roughly pentagon shape, which the building design reflected. President Franklin Delano Roosevelt was afraid the enormous building would interfere with the view of Washington from Arlington Cemetery, so he ordered the building moved three quarters of a mile down the river to an area that included the old Hoover Airport, a brick factory, a pickle factory, a race track, a low-income residential area known as Hell’s Bottom, swampland and dumps. Nevertheless, the original design endured, and the upside is that the unique design–five sides, five stories, five concentric pentagons joined by 10 connecting corridors–means you can walk from any one room to another in just seven minutes, despite the building’s size.
The Pentagon was built of reinforced concrete, made from 380,000 tons of sand dredged from the Potomac River and supported by 41,492 concrete piles. The use of concrete beams rather than steel ones saved enough steel to build a battleship.
The building as constructed was immensely strong; the area the airliner hit was even stronger, because it had recently been renovated under a building-wide program that’s been going on since 1994. The primary purpose of the renovation is to replace the ancient mechanical, electrical and plumbing systems with new ones. Asbestos is also being removed. Most importantly, however, the renovations included a web of new steel reinforcements, which may have delayed the collapse of the damaged part of the building for as much as 30 minutes, allowing hundreds more employees to escape than might have otherwise. As well, some offices were shielded by two-inch-thick, blast-resistant windows and walls lined with bullet-proof Kevlar cloth. New automatic fire doors and fire sprinklers were also functioning.
One aspect of the Pentagon’s original construction still caused problems, however; the roof consists of a layer of masonry, topped by wood, topped by slate. The wood ignited, allowing the fire to travel between the layers of slate and concrete, resulting in a very stubborn blaze that was hard to extinguish.
The Pentagon’s structural strength kept the airliner from penetrating all five rings of the building. In fact, the most severe damage was limited to the outer two rings, although a full third of the building was rendered temporarily unusuable due to smoke and water damage.
Rebuilding the Pentagon is expected to cost hundreds of millions of dollars (building it in the first place cost only around $50 million–but of course that was in 1940s dollars). Some commentators wonder whether it should continue to serve its present function, pointing out that on the opposite side of the building from where the jet crashed, the offices of the Secretary of Defense, the Secretary of the Army and the Chairman of the Joint Chiefs are all located on top of each other.
That’s only one of many questions being asked about buildings, security, and everything else that seemed normal and ordinary just last week.
