Going Vertical with Austin’s Waterline
This article is included in the Great Things: Issue 10 edition of the DPR Newsletter.
When complete, Waterline will be a 74-story mixed-use residential, office and retail skyscraper, and the tallest tower in Texas.
They identify urban landscapes without a word. They decorate postcards and serve as backdrops for city-dweller balconies and commutes to the office. Iconic skyscrapers give their homes personalities and proof of economic growth, but what makes them special to those who help erect them from the terrain below?
As an established tower contractor in downtown Austin, TX, DPR’s toolbelt for constructing some of the tallest, highest quality and most unique structural giants in the city is built on expertise and experience. And it because of that trusted expertise and commercial market prowess, they are on track to build Waterline, which will be the tallest tower in Texas: a 74-story mixed-use residential, office, hotel and retail skyscraper aptly named Waterline in homage to its proximity to downtown Austin’s Lady Bird Lake.
Building a project of this magnitude takes a lot more than expertise though. One key factor to achieving success is approaching the construction journey with an unwavering commitment to efficiency, which DPR sees as the only way to scale the quality that must go into every floor.
Growth starts at the bottom, and establishing the foundation for this unique tower involved its share of challenges. For the first time ever, the City of Austin contracted the general contractor to perform the underground piping for the chilled water system. Two 18-in. pipes were tied into an existing vault approximately 25 ft. deep under the road. Due to the project’s location in a very prominent and widely used intersection in the city, logistics and planning were crucial. Starting the work right after the globally attended SxSW festival in March 2023, DPR maintained a tight schedule despite unforeseen utility challenges, and turned the road back over faster than projected if the city were called on to perform the work. They even have scoped realignment of one of the major roads in the intersection to create a new drive lane.
Elevating Material Delivery
When prioritizing schedule, climbing north of 70 stories to deliver workers and material is a gargantuan task. Because of this, logistics of the tower crane and vertical transportation require intense planning and a process that is different from a more typically-scaled project. With Waterline, the common tower hoist serves as the mainline transport for the duration of the project and will reach all the way to level 74. All six cars on the hoist were custom built for this project—a lot more oversized than what you would normally expect. All cars will hit one common platform and then a single ramp into the building.
“Using a single ramp allows us to minimize the space needed to block off on the skin of the building, and much more easily, progressively remove the ramps and install the skin as we move up,” said project superintendent Emory Sweeney.
To put it into perspective, using the traditional hoist method for 74 levels, a project would need to wait for it to be topped out, the hoist to be fully removed, and then the skin installed, or “closing the zipper,” all the way down—a significant impact to the schedule and efforts facing the team.
“With the common platform here and holding the hoist off the building, once we're going to be done with phased levels, we'll pull this platform out, put the crash wall and curtain wall in and be done—progressively closing up the building as we go,” said Sweeney.
Knowing the importance of this method on this project, DPR visited previous projects by the hoist vendor in New York City, which boasts many “supertall” buildings, before selecting them to work with on Waterline.
A Giant Concrete Footprint
Future visitors will experience Waterline’s mixed-uses via grand three-part, three-floor tall lobbies, separated for residential, office and hotel spaces. However, each is home to mammoth monolithically placed, single pour concrete columns, expertly placed by DPR’s self-perform concrete team. There are 91 mega-columns planned for the tower, ranging from 30 to 53 ft. each and averaging 70 cubic yards. Their architecturally exposed finish will draw eyes to all who enter the floor-to-ceiling glass atriums. In addition, there are 24 complex teapot columns that line the lobbies co-starring in the drama of the space with glass elevators connecting the upper levels with the garage and a glass terrace with views of the neighboring Waller Creek—also in revitalization mode to accompany this landmark tower.
It's no secret that a 74-story tower needs a solid base and secure foundation, and all of these skillfully constructed concrete columns add more value to the structure than it does the aesthetics. The heaviest columns average close to 28,000 pounds, which is about equivalent to 21 of Austin’s most famous four-legged icons: Texas longhorn cattle.
The self-perform concrete showcase was one for the books: among challenging site logistics, design coordination, and managing the sizeable crews needed for a job of this caliber, the mat pour consisted of 3,213 yards, and the largest deck pour to date was 1,023 yards. And the tower is just starting to scale—there is 2,436,642 sq. ft. of elevated deck left to pour.
“What I’m most proud of on this job, is how our team has come together to take on the biggest and most challenging project any of us has ever, or will probably ever do,” said SPW concrete project manager James Dunn. “Everyone has stepped up to put in the time and effort to make this project a success and a great place to work every day.”
And before long, there will be more and more literal stepping up, as Waterline begins to ascend to its incredible goal. Teamwork on a daily basis will be crucial, efficiency mandatory, and as far as tracking progress goes? Well, all you have to do is look up.
Posted on November 9, 2023
Last Updated January 29, 2024