The Crenosphere Stadium--
The Ultimate Sports Facility

By Freda Grones

Simply defined, Crenosphere Domes—the newest members of the Monolithic Dome family—are huge, concrete structures ideally suited for indoor sports. Their diameters range from 300 to 1000 feet; their heights range from 75 to 500 feet. They can accommodate thousands of spectators and a virtually limitless number of activities. But—here's the best part—Crenosphere Domes are affordable and practical.

The Crenosphere's Advantages

• Significantly Lower Construction Costs – In some situations, the cost of building a Crenosphere could be half the construction cost of other types of sports facilities, with nothing sacrificed in playing space, spectator seating, concessions or other amenities.
• Interior Design Flexibility – The Crenosphere's interior adapts readily to almost any plan. Its inside is just space—beautiful, open space. There are no pillars or posts—only unobstructed space. Crenospheres can be single-level or multilevel; they can include mezzanines, hanging press boxes, concession and dining areas, spectator seating and lounges, restrooms and lockers.
• Exterior Design Flexibility – The variety of sizes and shapes make the Crenosphere ideal for football, indoor soccer, baseball, arena football, hockey, basketball, softball, tennis, etc.
• Energy Efficiency – A Crenosphere has superior insulation with an effective R60 value. This eliminates sudden changes or peaks in the Crenosphere's interior temperature and greatly reduces heating and cooling costs. What heating or cooling the dome requires can be provided by smaller or fewer units, running for shorter periods.
• Cost Efficient Maintenance – The concrete and other materials used in the construction of the Crenosphere make the structure extremely durable and low maintenance.
• Durability – The Crenosphere's life span is measured in centuries, not years. It cannot burn, blow away, or be eaten by bugs. Such durability means less costly insurance premiums, and more importantly, security.
• Security – A Crenosphere Dome can instantaneously become a disaster shelter and protect the population of a school or a community from the destructive force of a tornado, hurricane, or earthquake.

According to David South, inventing the Crenosphere took twenty years of research and experimentation, and just getting the patent took another two years. "We've created a different class of structure—one that makes building a stadium, arena or field house much more affordable for any city, athletic league, organization or individual who wants to build one," he says.

The Crenosphere costs less to build because of its construction process. A single contractor can build the shell, using readily available materials. Since most of the construction happens on the inside, not the outside, of the Airform, an efficient construction schedule can be maintained—one that does not depend on weather, temperature or daylight. With three shifts, construction can continue on a 24-hour basis.

The chart below gives approximate prices for various sizes of Crenosphere Domes. This estimated price includes the shell, ring beam and footing only.

Crenosphere Size and Cost*			Seating Capacity**
Diameter	Height	Cost	Football	Soccer	Baseball	Hockey	Basketball	Concert
400 ft	100 ft	$7 Mill	8,000	8,000		20,00	24,000	25,000
450 ft	112 ft	$9 Mill	16,000	16,000		35,000	40,000	41,000
500 ft	125 ft	$12 Mill	24,000	24,000	20,000
600 ft	150 ft	$19 Mill	50,000	50,000	30,000
*Cost is for the Crenosphere shell only (2007 Prices). Does not include interior finish.
**Typical seating capacity. Actual capacity varies greatly depending on seating configuration. This table is for Crenospheres up to 600 feet diameter, approximately the size of the Astro Dome in Houston, Texas. However, Crenospheres may be built as large as 1000 feet.

MDI's consulting architect Rick Crandall cites another of the Crenosphere's advantages: its effectiveness in large assembly situations, such as those for sports activities. "Domes create the best assembly occupancies that can be had. There's no better way to get the maximum number of people in the smallest volume all facing the same direction," Crandall says. "There's no better shape than round. With dome technology, we don't have to accept the limitations of traditional architecture."

Designed as a field house, a Crenosphere with a diameter of 400' or more can comfortably accommodate several activities, each with its own space, plus removable or permanent spectator seating.

"I suspect that almost any college or school would love having an indoor field house where several activities could be practiced simultaneously—regardless of the weather or the temperature or the time of day," David says. "Now it's possible. For example, in one Crenosphere you can include an artificial grass field for football or soccer, a hard floor for tennis or basketball, and a running track along its inside perimeter. You can heat or cool it if necessary, and you can use it any time of day or night."

The Crenosphere is the ideal structure for controlling the weather in a play space. David says, "If you want to surf, you can build an indoor wave pool and keep it swimmingly warm.

"Or consider this ultimate sports facility: an indoor ski mountain. You can build a ski mountain inside a Crenosphere in the middle of a hot, densely populated city. Its residents can practice their skiing skills without going out of town and regardless of the weather."

The cost effectiveness of a Crenosphere Dome extends to its on-going energy consumption. Dr. Arnold Wilson, consulting engineer with MDI and retired professor of civil engineering at Brigham Young University, says that the Crenosphere's superior insulation is an automatic result of the foam layer sandwiched between the Airform and the concrete.

As for the cost of on-going maintenance, David comments, "Because the Crenosphere does not have a roof such as traditional buildings have, the Crenosphere does not have roof problems. The roof of the Crenosphere is simply the uppermost part of the dome. There are no shingles to blow off or develop leaks. Costly roof problems are something we hear about frequently from folks involved in the long-term upkeep of traditional structures."

 Considering the Crenosphere's advantages—its affordability and flexibility—its effectiveness as a disaster shelter—it truly is the ultimate sports facility—the dream stadium! But certainly not an impossible dream. The ultimate sports facility, the Crenosphere Dome, is realistically reachable.

177 Dome Park Place - Italy, TX 76651
Tel (972)483-7423 - Fax (972)483-6662