While Boston is famous for its annual marathon, last year's $90 million parking expansion at Boston Logan International Airport (BOS) was definitely much more of a sprint. As soon as the Massachusetts Port Authority awarded Arrowstreet/Parsons Brinckerhoff the project contract in May 2014, the design team started its stopwatch. Most of the 1,700-space expansion needed to be ready for use by Thanksgiving 2015.
Why so fast?
Project: Parking Expansion
Location: Boston Logan Int'l Airport
Size of Addition: 10 floors; 1,896 total parking spaces (1,700 for passengers; 196 for hotel guests)
Garage's New Capacity: 12,000 spaces
Cost: $90 million
Funding: Bonds backed by airport parking revenues
Timeline: Contracts awarded May 2014; 7 of 10 floors completed by Thanksgiving 2015; remaining floors completed by Feb. 2016
Engineer: Parsons Brinckerhoff
Construction Manager: Turner Construction
Concrete: Blakeslee Prestress
Facade Wall Design/Fabrication: EXTECH/Exterior Technologies
Facade Wall Testing: Intertek Architectural Testing
Facade Wall Installation: Ipswich Bay Glass Co.
Hallmark Feature: Kinetic wall with 48,000 anodized aluminum flappers that swing individually in the wind
"Customer service," explains Sam Sleiman, director of capital programs for Massport. "We were overflowing. Our parking spaces were full almost 25 weeks out of 52. We needed those 1,700 spaces."
To help offset the inconvenience to customers, Massport began valet parking vehicles at no extra charge when the airport parking lots filled up. In addition to finding open parking spots off-site, personnel had to coordinate the retrieval of passengers' vehicles when they returned. Needless to say, various levels of airport personnel were eager for crews to finish the parking expansion.
"The biggest challenge was the schedule," recalls David Bois, an Arrowstreet principal. "It was incredibly fast-tracked." In retrospect, Bois estimates that the 10-story pre-cast concrete structure was designed and built at least twice as quickly as other comparable garages Arrowstreet has designed.
"The challenge was to build in enough design in the early stages so that in the end we would be comfortable that it would have a design that was unique and interesting," Bois explains. By fall, Arrowstreet began sending drawings to its pre-cast concrete partner, Blakeslee Prestress.
Beyond the tight schedule, the design/construction team faced unusual logistic challenges. Any additions to BOS' Central Garage could not disturb guests in the adjacent Hilton Hotel-during construction or while in operation afterward.
Massport financed the $90 million garage and walkway project with bonds backed by BOS's parking revenues.
Although speed was a key priority, aesthetics were not relegated to the slow lane. The new parking addition needed to adhere to Massport's new design philosophy for major capital projects. As Sleiman describes it, the port authority wants to create facilities that make passengers feel comfortable, as if they're at home.
With the emphasis on "smart design," the garage expansion needed to work efficiently, but also be a memorable facility, he adds. "We want to bring glamour to travel."
When seeking proposals for the project, BOS consequently looked for teams led by architects, not engineers. Then, it slotted the architectural firm that was selected as the project leader.
"This gave us the best opportunity to lead the process and to integrate design into the entire process," Bois comments.
Specifically, Massport wanted the exterior façade of the addition to break up the visual impact of BOS' massive Central Garage. Officials did not want the expansion to look like a "chunk of concrete" standing in the middle of an airport, recalls Sleiman. Furthermore, a well-designed façade was needed to assure Hilton management that garage customers would not be looking directly into the hotel and vehicle headlights would not be shining into guest rooms.
The initial design included seven floors and placed the garage 50 feet from the hotel, but the final 10-level design creates a 100-foot gap.
Massport originally asked Arrowstreet to consider using a screen to create the visual barrier it required. Because the garage is an open-air structure, a screen could leverage natural lighting and preclude the need for an expensive ventilation system.
"We challenged ourselves to make it something people would be interested in looking at," Bois recalls. "It would be more than just attractive, but something that would catch your interest-like watching waves or smoke."
So instead of a screen, Arrowstreet specified a kinetic wall, with thousands of individual metal pieces that move in even the slightest breeze. The wall, which spans roughly 23,000 square feet, is dynamic and thus ever changing, like the waves or smoke, Bois mentions.
Inspired by the work of California artist Ned Kahn, Bois and other team members traveled to Pennsylvania to study a kinetic wall he designed for the Pittsburgh Children's Museum. While there, they also met with EXTECH/Exterior Technologies, the local firm that fabricated Kahn's design and eventually the wall for BOS.
"We worked together through the drawings and working mockups to develop the final design," explains Kevin Smith, the company's director of product application and development. "They were interested in opaque, curved flappers. We went through a series of recommendations regarding construction, flapper materials and finishes."
Predicting the ultimate price of the kinetic wall was challenging, but important, for Arrowstreet. "This was not something that was easy to estimate," acknowledges Bois. "[But] it could not show up at installation costing three times more." Massport declined to disclose the final price of the kinetic wall.
From a design standpoint, the wall includes 48,000 anodized aluminum flappers attached to metal rods and separated by 1-inch gaps, so each flapper can swing freely and independently of the others. To add even more visual depth, the individual 6-by-8-inch pieces contain mild S-shaped curves.
In a light 5-mph wind, the flappers move slightly; and with winds of 15 mph or more, "you really get some kinetic movement," Smith remarks.
Because the flappers are designed not to touch each other, the wall creates minimal noise-an issue of initial concern for hotel management. "In a mild wind, some people say it sounds almost like a waterfall," says Smith.
The wall is, however, designed to withstand Boston's characteristically strong winds. EXTECH subjected mockups to hurricane forces (Category 3 winds, up to 120 mph) during a series of six sessions at Intertek Architectural Testing. "Everyone wanted to know that the flappers would not detach and become flying debris," explains Smith.
It took EXTECH personnel three months to cut and form each flapper and another two months to hang them on panels. Ipswich Bay Glass, an area curtain wall installer, then spent about four weeks installing the panels on the exterior of the garage last August. Each panel hooked into place much faster and easier than originally envisioned, Bois recalls.
Frames holding the panels of flappers are covered with steel mesh screen to prevent visitors from reaching in and bending the flappers.
In addition to facing the hotel, the kinetic wall also serves as a backdrop to the airport's 9/11 memorial, an eight-story glass sculpture that encases two glass panels etched with the names of passengers and crew members aboard the sabotaged flights. The airport has a particularly close connection with the 9/11 tragedies, because the two flights terrorists used to strike the World Trade Center originated at BOS.
On Your Mark, Get Set
Onsite work for the parking addition began in early 2015, with Turner Construction Co. serving as construction manager. Before crews started moving dirt and concrete, the Arrowstreet/Parsons Brinckerhoff/Turner Construction team used 4-D computer modeling to depict the garage addition, map out projected traffic flow in the expanded space and develop a timeline to construct it. Updates to the work schedule were communicated to stakeholders at weekly meetings.
The project site was a sliver of land leased to the hotel for its own parking needs. The lot contained tunnels for underground utilities and an enclosed second-level sky bridge that allows hotel guests to pass through the Central Garage and into the terminal. Neither the tunnels nor the sky bridge could be disturbed during construction, notes Camille Bechara, Parsons Brinckerhoff's manager for the project.
Although Hilton lost use of its 196 surface parking spaces during construction, crews worked around hotel operations when possible. Pile driving, for instance, was limited to certain daytime hours, Bechara notes.
Construction also temporarily limited capacity in the airport's Central Garage; so it was cause for celebration when crews finished the first seven floors of the addition just before Thanksgiving week 2015, providing about 1,000 additional spaces for holiday travelers. "The first week we were open, it was full," Sleiman recalls.
Work continued on lighting and mechanicals for the top three floors, and the final 700 spaces were ready in February 2016, just in time for traditional winter breaks.
Now, the Central Garage has 12,000 spaces. Customers still use the same entrance and exit, but the newly expanded structure includes a second ramp system to facilitate increased traffic. Designers kept ceilings on individual floors as high as possible to help airport visitors find their vehicles and add a sense of security, explains Bois.
"I have heard from many, many passengers, and they really, really like it," Sleiman reports, noting that the kinetic wall is a particularly pleasant surprise. "One of our goals is for this wall to be viewed as art. They don't recognize there is an addition to the garage, because it is hidden behind the facade."
The kinetic wall also helped BOS make the most of the dollars it spent complying with state requirements for public art in large capital projects. "We combined art with a need to shield the garage," explains Sleiman. "It was a win-win."
Inside the garage, Massport opted for upgraded finish materials, so the walkways and elevator lobbies resemble those in the terminal. "As soon as the passenger enters the lobby, they feel they are walking in the terminal because everything looks like the terminal. Their anxiety levels go way down," Sleiman comments.
Each lobby in the new areas of the garage also has an interactive kiosk, similar to a giant iPad, which allows airport visitors to check the status of flights and find gate locations, shops and dining options. Maps of the garage assist visitors as they return to collect their vehicles. Lobby areas in the original Central Garage are slated for similar updates later this year and early next.