A Fulfilling Career
“This has been a most exciting ride for me – one that has lasted my whole life,” said Dr. Arnold Wilson.
Referring to his 40-year teaching career as a Professor of Civil Engineering at Brigham Young University (BYU) and his more than 30 years as Monolithic’s Senior Consulting Engineer, Wilson added, “It’s just been a wonderful trip for me. It’s been exciting. I have done things that I had never even dreamed that I would do.”
Those “things” include some 30 years of teaching classes on thin shell concrete dome construction and counseling his students, some of whom now have careers of their own as Civil Engineers specializing in dome construction.
As a student at BYU, Wilson got to know Harry Hodson, a professor of engineering, who gave Wilson some articles on thin shell domes. “I was immediately absorbed and fascinated,” he recalled, “and eventually asked Professor Hodson if I could do my master’s thesis on thin shell domes, and he said ‘yes.’ That really marked the start of my working with domes.”
In 1961, Wilson became involved in the construction of a giant ice skating rink in Provo, Utah. He described it as, “a tri-axial elliptical dome, constructed using an earth form. It was 240’ long, 160’ wide, and 40’ high at its center but only 3 1/2" thick.
Over the years, this dome became a supermarket that residents dubbed, “Ream’s Turtle.” Although structurally still sound, it was razed – with difficulty – in 2006 to make room for new development.
Crediting the Egg!
Dr.Wilson doesn’t credit human ingenuity for the invention of a dome — he credits the egg. He said, “The egg has always fascinated me. You can see that it’s the shape and structure of the shell that gives it its strength. Much the same is true for a dome, and I think we borrowed from nature when we began building domes.”
Wilson sees a dome’s inherent strength as one of its greatest advantages, particularly in the future. He said, “Domes are just too good of a thing not to gain in popularity. They can withstand just about any force, and they are economical to build and maintain. What more can you ask?”
Wilson reinforced his point by recounting a 1988 incident, in Alabama, involving a fire inside of a Monolithic Dome, capable of holding one million bushels of grain. This dome, 150’ in diameter and 75’ in height had a hopper that sloped toward its bottom, making its center 20’ deeper. A tunnel and conveyor system at the base of the hopper removed grain from the dome.
“The fire apparently started in the tunnel where gases built up, as the grain deteriorated or fermented, but were not properly eliminated,” Wilson said. “I was called to help determine where holes could be cut into the dome, so the fire could be fought more effectively. At that point, the dome contained 300,000 bushels of grain. The fire had been going for 60 days, one semi-truck load of carbon dioxide had already been injected into the dome to extinguish the fire.
“Before the cutting decision could be made,” Wilson continued, “they had an explosion. The dome’s top, acting like a relief valve, blew off, creating a skylight of about 100’ in diameter. The sound of the explosion woke people as far as four miles away. But here’s the wonderful part about this whole incident: the dome contained the explosion. Escaping gas sucked the debris back into the dome so that lives were not lost and other property was not damaged.”
The incident also proved a principle once demonstrated in a class Wilson attended at BYU. “The professor covered the hole in one end of a spool of thread with a scrap of paper,” Wilson recalled. “Then he blew through the other hole; the paper stayed in place. To our amazement, the harder he blew, the tighter the paper clung to the spool, because the air going around the paper sucked it down. That same principle accounts for the dome containing the explosion.”
In the years that followed, Wilson continued experimenting with small domes, some using earth forms, some using rebar cages. His goal: finding an affordable method for constructing domes.
By 1975, Wilson had patented a form, much like a collapsible umbrella, over which a dome could be built.
“But then,” Wilson said, “I met David South and he had a better idea and patent than mine — the Airform.” That meeting marked the beginning of a personally and professionally rewarding relationship for both.
Like parents who may love their children equally but remember their first-born with more excitement and in greater detail, Wilson still thinks of one of his first, air-formed dome projects as the most challenging and exciting. He said, “I was the structural engineer for an ongoing project that involved building three huge domes in three different States. They would all be used for the storing of coal and limestone, that eventually would be burned to generate electricity.
“They were huge — 260’ in diameter and 130’ in height. It was my job, as structural engineer,” Wilson continued, “to determine how much concrete and steel were needed and where it had to be placed. Many people had their doubts. Some were absolutely sure a dome that size would never work. I always expected it to work — and it did!”
Asked to define small and large domes, Wilson chuckled, “The answer to that depends on whom you ask and when. In 1975, a dome with a diameter of 100’ was considered large. Today, that dome is small.
“Today we define domes with diameters of 300’ or more as large. The future will probably see 300’ diameter domes as small. It’s large to us, right now, because the largest one built, to date, is 260’ by 130’.”
Wilson said that in 1975 David South asked him, “How big can we go?” and he answered, “I’m thinking 800’ diameter.”
“Many, many long talks followed,” he added. “And the experimenting at BYU, cosponsored by Monolithic Dome Institute and Dome Technology, began. Twenty-three years later we know we can do diameters of 1000’ with a Crenosphere Dome.”
According to Wilson, when building a Crenosphere Dome, a cable net placed over the outside of the Airform prevents these gigantic expanses of fabric from tearing, and concrete ribs on the inside of the Crenosphere make its increased diameter possible.
He explained, “A Crenosphere differs from a Monolithic Dome in two important ways — one on the outside and one on the inside. On the outside, a steel cable net is secured to the dome’s foundation, over the Airform, before inflating begins. When the Airform is inflated, the fabric pillows out between the cables, forming a series of connected smaller domes — like a spherical quilt.”
On the inside, the Crenosphere is first sprayed with foam, then crisscrossed with rebar ribs, and sprayed with concrete. “Those ribs,” Wilson said, “give the Crenosphere more depth, but not weight, and create row upon row of small domes — thus eliminating the problem of snap-through buckling.”
Wilson predicted an exciting future for domes. For example, he sees them as a practical means for providing low-income housing and said, “Housing for the poor is a big problem, and it’s here now. Domes can definitely be the housing-answer for the masses, particularly in less developed countries. People can be taught to build their own small, thin shell domes using an Airform or a pre-cast segment.
“Either of these could be used repeatedly or become a permanent part of the structure. Local materials could be used that would make the domes strong and fireproof. The domes could be 16’ in diameter and provide 200 square feet of living space — that’s a luxurious area in many parts of the world. Dome building makes an ideal do-it-yourself project, and the best way to go when you want to help someone. It’s better to teach people how to do for themselves than to just do for them.”
Wilson thinks domes may play a role in the communities that futurists describe as closed complexes within which people will live, work, shop and socialize. He said, “Economically speaking, Monolithic Domes would be ideal for such a complex. But before that happens, we have to get people to accept the roundness. If, for instance, they could see the roundness of the structures as a visual that psychologically promotes a feeling of communal togetherness, they would be more accepting of these new architectural shapes. Then circular shapes could be a big selling point.”
Asked if weather changes and increasing violence within our society might promote dome building, Wilson said, “People are definitely concerned about safety. I think they would be interested in Monolithic Domes if they knew about them. We have to get the information out. I think the way to go is to get the architect groups informed and interested. They are very influential.
“Unfortunately, growing violence is another change that could stimulate popular interest in domes,” Wilson added. “People living in cities are experiencing drive-by shootings. Think how scary that is for someone living in a wood frame house that a bullet can easily penetrate. Masonry might stop a bullet. It might. A Monolithic Dome would stop it.”
Wilson predicted domes in outer space: “We will build spheres on the moon and probably other planets. Airformed domes will make ideal space stations. They’re strong, can use local materials and are the least expensive to construct. Inflating the Airform would be easy because in a vacuum it takes very little to do the inflating. So you can just use a pressure cylinder to inflate the Airform. The problems that have to be solved have to do with constructing in a different gravity.”
“I believe Arnold has engineered more thin shells than anyone else, living or dead,” Monolithic’s president, David South said. "Those projects include more than 1500 thin shells located throughout the United States and in 40 other countries.
“There’s what I call a ‘train of super engineers’ – professionals, over the ages, primarily responsible for the development and advancement of thin shell concrete domes,” he continued. “Well, when you talk about that train, you have to include Arnold. When it comes to the engineering of domes built using Airforms, Arnold is a pioneer. I would put him directly after David Billington” (Professor of Civil and Environmental Engineering, Princeton University, NJ).
Wilson agreed with that placement. He said, “Billington wrote a very excellent book. I used both the first and second edition as class texts until I retired from teaching in 1997. But Billington didn’t do a lot of domes. He did reactors for power plants, cooling towers for big, electric power plants and some other exotic things. Writing his book was the big thing. He helped a lot of people when he did that.” (David P. Billington wrote Thin Shell Concrete Structures, McGraw-Hill, 1965 and 1982.)
Wilson met Dr. Billington through Committee 334 – a group of professionals from American Concrete International and the American Society of Civil Engineers who are interested in thin shell structures. About that meeting, Wilson said, “He (Billington) knew that over the years I had used his books. Actually, I found some errors in them. That, in itself, was no big deal because all books have mistakes. So, I just marked what I found and sent them to the publisher. Years later, when he and I were talking he thanked me for sending in those corrections.”
Through Committee 334, Wilson also met Anton Tedesko (1903-1994) whom he described as a “practicing engineer.” He said, “Tedesko came out of Germany and he had experience there before coming here. He did some very large structures – aircraft hangars and structures with big arches. Way ahead of his time and very, very excellent work.”
Dr. Arnold Wilson writes a book!
It took a long, hard, persistent time for David South and others at Monolithic to get Dr. Wilson to put his expertise into a text for engineers, architects, builders and students of civil engineering.
In 2005, Wilson finally did it. He wrote Practical Design of Concrete Shells – 398 pages of domes designed as commercial, public or private facilities. They include unique residences as well as huge domes with diameters of 1000 feet, airplane hangars and water tanks. This book is available online.
Planning his retirement
With the book completed and available to others, Arnold Wilson and Joyce, his wife, are looking forward to some free time and a little traveling.
“As I said, this has been an exciting and rewarding time for me. Now I’m ready to retire,” Wilson concluded.
December 28, 2007