Building an aquarium is complicated. But building a spectacular 21st century aquarium inside the footprint of a 19th century train shed designated as a National Historic Landmark adds multiple levels of complexity. Fortunately for McCarthy Building Cos. Inc., which built the 2-story, 120,000-square-foot St. Louis Aquarium at Union Station, construction challenges are its strength.
A signature element of the $187 million redevelopment is that the aquarium provides visitors with immersive perspectives of underwater life in the world’s rivers, streams and oceans, including up-close viewing of more than 13,000 animals, from 257 species, in 44 exhibits. This diverse range
of aquatic animals—from freshwater and marine environments—are housed in 1.3 million gallons of water, including a 250,000-gallon shark habitat that serves as the centerpiece attraction.
HISTORY OF ST. LOUIS UNION STATION
Located adjacent to the heart of downtown St. Louis, St. Louis Union Station first opened to the public in 1894 and became one of the world’s largest and busiest passenger rail terminals. Designed by Theodore Link, an architect for the 1904 World’s Fair, the iconic structure encompasses an 11.5-acre train shed, headhouse and midway.
Union Station closed its doors in 1978 when Amtrak relocated its St. Louis station, but the facility reopened in 1985 following its conversion into a festival marketplace with retail, restaurant and hotel components.
When it was purchased by Lodging Hospitality Management in
2012, St. Louis Union Station was completely transformed again into a family entertainment and tourist destination. Today, in addition to the hotel and aquarium, the complex includes several new restaurants, a ropes course, mirror maze, 200-foot-high observation wheel, carousel and mini-golf course.
Retrofitting space that has a national historic designation requires leaving the entire existing infrastructure in place, including protecting and preserving the original columns, footings, foundation, underground piping and other infrastructure.
Given these restrictions, builders had to figure out the best way to design and in- stall 17 independent life-support systems to accommodate each of the unique animal species that lives in each exhibit, as well as separate holding tanks, quarantine tanks, piping, ozone and temperature control systems to provide individualized, treated water to each exhibit. In addition, five overhead viewing areas, a switchback tunnel, and deep-water-area panels needed to be built to create an engaging and immersive visitor experience.
CHALLENGES ALONG THE WAY
The most recent set of as-built drawings for the structure dated to the late 1800s, so one of McCarthy’s first steps was to laser scan the entire former train shed portion of the facility. Laser scanning enabled team members to accurately assess existing conditions and mitigate future design issues that would potentially delay or complicate the project.
The design and construction team worked together to design, coordinate and install an underground pipeline system encompassing more than 10,000 linear feet of pipe. Custom-built piping assemblies—ranging in size from 2 to 24 inches—service the 17 independent life-support systems, each of which is designed to accommodate the animal species that occupy a specific exhibit. Building Information Modeling (BIM) facilitated the entire process—from model to field layout.
Construction activities also included installation of 1,552 square feet of permanent acrylic panels, ranging in size from 3 by 3 feet to 16 by 18 feet and weighing a total of 53,000 pounds. BIM and laser scanning enabled the team to verify tolerances and embed locations before placing each acrylic panel, ensuring precise placement on the first setting and averting the significant installation expense of additional placements.
Other construction challenges involved controlling noise and dust while working in close proximity to an operational 567-room hotel and adjacent restaurants.
Photos: McCarthy Building Cos. Inc.