2005

Georgia Aquarium

Jeff Swanagan (1957–2009)

Atlanta wants to build an aquarium tank large enough to comfortably house four whale sharks, along with thousands of other fish and rays. Assume that the average whale shark is 32 feet (10 meters) long and weighs as much as several African elephants. How do you make an aquarium that big? These were issues faced by the engineers working on this structure, including the founding executive director, Jeff Swanagan, who was responsible for much of its creation and design.

The typical Olympic-size swimming pool (50 meters long, 10 lanes wide) holds about 660,000 gallons (2,500,000 liters). The Georgia Aquarium Ocean Voyager exhibit, at 6.3 million gallons (24 million liters), is roughly the size of 10 Olympic swimming pools. This immense tank, which opened in 2005, is 263 feet long (80 meters), 125 feet wide (38 meters), and 33 feet deep (10 meters). Its walls, some up to three feet (1 meter) thick, are made of Agilia concrete, a special mixture that flows almost like water yet does not allow the aggregate to settle out while it is curing. This means that when workers removed the formwork, there were no bubbles or voids anywhere in the concrete.

The main viewing window measures 23 feet (7 meters) high and 61 feet (18.6 meters) wide. The water behind that window has a combined weight of approximately 50,000,000 pounds (23,000,000 kg). How are engineers going to keep that water from bursting through the window? They made it out of acrylic measuring two feet (0.6 meters) thick. The advantage of acrylic, compared to glass, is that it is 17 times stronger while having half the weight.

The next challenge is filtration. At the Georgia aquarium, the total exhibit space is 10 million gallons (38 million liters). To filter this much water requires an immense pumping capacity. The total flow rate of the filtration system is 300,000 gallons (1.1 million liters) per minute, powered by over 500 pumps totaling 5,500 hp. Sand filters take out anything larger than 20 microns. There are also protein skimmers that use fine air bubbles to eliminate unwanted organics from excess food and fish waste.

SEE ALSO Concrete (1400 AAA), Water Treatment (1854).

The biggest aquarium in the world, Atlanta, Georgia, USA.