The Ballpark
T-Mobile Park took just 27 months to build, a remarkable feat for such a complex project. Construction formally began with a groundbreaking ceremony in March 1997 and the first game at the new ballpark was played in July 1999. The ballpark cost $517 million to build, including $126 million contributed by the Seattle Mariners.
Huber, Hunt & Nichols, Inc. formed a joint venture with Kiewit Construction Company to build T-Mobile Park. Together with architects NBBJ, the team came up with creative construction techniques to complete the project in an amazingly short amount of time.
A major challenge was the site, a former tidelands with soil the consistency of oatmeal—not solid enough to support a new sports stadium in an area known for earthquakes. Construction crews drove 1,400 pilings into the ground an average of 90 feet below the surface until the piles connected to bedrock.
The ballpark and its retractable roof were actually built as two separate projects, and T-Mobile Park was constructed as seven different buildings due to seismic requirements. The building can shift against itself without breaking during an earthquake. That also made it easier to coordinate the work being done during construction.
As many as 1,000 people at any time worked on the ballpark construction project.
The Roof
The T-Mobile Park roof is a marvel in its own right. It spans 655 feet, covers 8.9 acres, and weighs more than 11,000 tons! The roof moves on wheeled, travel truck assemblies driven by 96 ten-horsepower motors. The travel trucks were built at the former Ederer Inc.'s crane shop in Seattle just blocks from the ballpark.
When the roof opens, it moves almost completely off the seating bowl, leaving fans inside to bask in the benefits of an outdoor ballpark—sunshine, open air, and spectacular views of the great Pacific Northwest scenery. It takes less than 20 minutes to close or open the roof.
When open, the arched panels stack over the railroad tracks at the ballpark's eastern edge. Two smaller end panels tuck under the larger center panel, forming a grand arch similar to the old railroad stations found throughout Europe.
To close, the roof rolls back in the opposite direction, acting like an umbrella over the fans and the field to protect against rainy weather while preserving the open-air environment. Because the roof sits on legs mounted on wheeled mechanisms, the roof forms a canopy over the bowl so that, even when the roof is closed, the open sides provide views of the city.