Not very long ago, I picked up at the Raleigh-Durham International Airport a prominent and very busy structural engineer who had flown in from Chicago to give a talk at Duke.
As we were driving toward Durham, I asked him if there were any structures in the area that he would like to see during his brief visit.
He did not hesitate before naming just one: the Dorton Arena.
Since we were driving in the opposite direction from Raleigh and the North Carolina State Fairgrounds on which the arena sits, and since we did not have much time to spare before his talk, I told him that we would risk getting caught in traffic if we went there first.
Perhaps we could go by after his talk.
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Yet for all of its influence on subsequent design and construction, the significance of the unique Dorton Arena remains relatively unknown outside the structural engineering and architectural communities.
The Dorton Arena, completed in 1952, was the first stadium-like structure designed to enclose a large, covered, column-free space.
It is thus the predecessor of such covered stadiums as the Houston Astrodome, completed in 1965, and the superdomes that so dominate sports-stadium design today.
The Dorton Arena was the first indoor stadium designed entirely as a large column-free space.
The final column-free area was 300 feet in diameter with 25,000 square feet of arena space.
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This design was possible due to the use of the revolutionary combination of compression ‘rings' and cables in tension to support the roof.
The Dorton Arena was the first use of a cable-supported roof system in the world.
The principle of using cables to support a roof, albeit not a permanent one, is said to have been employed in the Roman Colosseum 2,000 years ago.
Some suspended roofs were evidently used in Russia at the end of the 19th century, but steel strips rather than cables were used as the support elements.
Suspension-bridge development, especially in the later 19th and early 20th centuries, provided a testing ground for using steel cables in large-scale tension structures, but the Dorton Arena's permanent cable-supported roof system was the first in the world on such a large-scale structure, one measuring the length of a football field in each direction.
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Instead of relying strictly on the primitive principle of compression, in which loads are carried by bearing down on what supports them, as do pyramidal piles, planar walls or circular arches and domes of stone, the Dorton Arena is a structure whose roof is supported in tension.
Tension structures carry their loads by resisting being pulled apart.
Suspension bridges, with their graceful cables, are very prominent tension structures.
Tents are also tension structures, with their fabric stretched over poles the way the bridge cables are slung over towers.
Indeed, although not often visualized in this way, a large circus or event tent can appear in profile or silhouette to resemble a suspension bridge or series of suspension bridges in tandem.
Because tensile structures work by resisting being pulled apart, they also have to pull against something; thus, suspension bridges require anchorages, as tents require stakes, to maintain their configuration.
Among the Dorton Arena's unique features is the elimination of any anchorage or stake-like components, thus making it a more economical and elegant structure.
So, how does it resist the essential tension?
The roof cables pull against a pair of crossed and inclined concrete parabolic arches that are perhaps the arena's most dominant feature.
Like all arches, these work in compression, and the pull of the cables in the plane of each arch is transformed into a compressive force that flows down the legs of the arch into the ground.
The structural action of the building has been given the anthropomorphic interpretation of being like two men who lock arms and pull against each other.
If they were standing upright, their mutual pulling action would tend to make them fall toward each other.
To keep this from happening, each of the men can place his feet behind those of the other as he leans backwards and pulls with his arms.
In this cross-tied stance, each of the men would only fall backwards if he let go of the other.
However, the men might also slide on the ground if they did not have their heels dug in or their legs tied together in some way.
An analogous action is going on beneath the surface in the Dorton Arena, where the feet of the arches bear against massive abutments and the crossed legs are tied together with steel cables.
The structural action of the arena as embodied in the human model is considered a brilliant, original and extremely elegant solution to the ever-present engineering problem of equilibrium.
By making the structure's arms out of steel cables, which are very efficient in tension, and making the leaning body out of concrete, which is very efficient in compression, the best properties of both materials are exploited.
If the arches were not inclined-if the men were not leaning backward-the structure would not work.
For two men to pull against each other while standing upright, an additional structural element would be required.
This could take the form of another man standing behind each and holding him back with a rope.
Then the structure would be analogous to a suspension bridge, with the backup men acting like anchorages.
As beautiful a structure as a suspension bridge can be, its need for anchorages (and the extra cost they entail) puts a blemish on it as a less efficient structure than the Dorton Arena.
But how did this elegant structure come to be, and why is it on the State Fairgrounds in Raleigh, North Carolina?
The origins of the Dorton Arena lay in the postwar years, when J. Sibley Dorton, a veterinarian turned fair manager, promoted long-range plans "for future expansion of the North Carolina State Fair into a permanent State Exposition on a year-round basis" in the temperate climate of the Piedmont.
He envisioned a "modern, well-planned Exhibit Arena and Assembly Building, adequate to accommodate and seat 15,000 people."
The building, which was the centerpiece of his vision, would "provide adequate facilities in the amphitheatre for the proper showing and sale of all forms of livestock, as well as shows for automobiles, textile machinery, and every other conceivable type of industrial shows and sales, as well as all forms of sports and athletic events."
Commissioned in 1949 by North Carolina State Fair manager J.S. Dorton, the new building was intended to be a livestock judging pavilion.
The architect chosen to flesh out Dorton's vision was William Henry Deitrick, who was born in 1895 in Virginia.
He developed ties to North Carolina by attending Wake Forest College and marrying Elizabeth Hunter of Raleigh, the city in which he set up his architectural practice in the mid-1920s.
He thus had more than two decades of experience designing buildings and planning land use in the state before he received the North Carolina fairgrounds commission.
Since the late 1930s, Deitrick's firm had practiced out of a structure dubbed the "ivy tower office" owing to its location in the renovated Raleigh Water Works, with its distinctive octagonal vine-covered granite tower.
The Tower-as the building inevitably came to be known-has been described as "a professional training Mecca for young architects" of the time.
Among the young architects that Deitrick engaged periodically as consultants were Matthew Nowicki and his wife Stanislava.
J.S. Dorton Arena Layout Video
Matthew Nowicki was born in 1910 in Russia but received his architectural training in Poland, where he began to practice.
Among his commissions were a sports center in Warsaw.
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