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3 Questions for Quentin Brathwaite, Port Authority
Port Authority's assistant director of WTC Construction, Quentin Brathwaite
December 24, 2009
It’s been a year of tremendous progress at the World Trade Center (WTC), where for the first time in eight years one can plainly see structures filling out the site, like an early glimpse of the future.
As owner of the WTC, the Port Authority is responsible for the massive physical development taking place across the site’s 16 acres. The bi-state agency is now at work building what will be the city’s tallest tower, 1 World Trade Center, and the two largest man-made waterfalls in the world, the National 9/11 Memorial’s reflecting pools. As those two enormous projects continue, the Port continues to excavate for and construct the future WTC Transportation Hub, as well as the new South Bathtub, where the Vehicular Security Center entry will be built.
At the center of it all is Quentin Brathwaite, the Port Authority’s assistant director of WTC Construction. Just as the complexities of WTC site redevelopment are unparalleled, so are Mr. Brathwaite’s job duties, which include vast engineering and logistical planning, coordination between the various stakeholders and construction managers, and the responsibility of constant community outreach and responsiveness. In fact, the duties of the latter alone prompted the Port to create and entirely new division within the WTC Department, the Office of Program Logistics, headed by Mr. Brathwaite.
We asked Mr. Brathwaite three questions about the progress his team’s made at the site, and how it’s finding new ways to meet WTC construction demands.
The Port Authority is operating several giant cranes inside the WTC site, with one “mega crane” in place -- how does its size benefit construction progress?
Mr. Brathwaite: The largest crane that will be used during the reconstruction of the World Trade Center -- a Manitowoc 18,000 -- is already on site at the western edge of 1 WTC. With an 800-ton capacity and a boom longer than 400 feet, assembly of the 18,000 requires nearly a full week.
It was used to place some of the jumbo steel columns that frame 1 WTC’s perimeter and first three floors of the building. Each individual column is 60 feet long and weighs 70 tons. (To put that in perspective, every 12 inches of steel equals the weight a Honda Civic.) Currently all 24 jumbo perimeter columns have been installed and are clearly visible to passers by. In fact, additional steel has been installed above the columns and structural steel currently tops out over what will be 1 WTC’s fifth floor.
The Port Authority’s contractor responsible for installing WTC Transportation Hub steel will reposition the 18,000 in the East Bathtub in the first quarter of 2010. Cranes of this size are absolutely essential for placing the massive steel members that comprise the structure of 1 WTC and the Transportation Hub. Just as the 18,000 was crucial to placing 1 WTC’s huge perimeter columns, it is needed to install the largest and most complicated steel members required to realize the iconic design of the Hub.
The Port Authority is working closely with its contractor to ensure the crane obtains the necessary approvals and is repositioned on the site in a manner that minimizes impacts on surrounding traffic and the community. While the coordination and planning required to bring immense cranes such as the 18,000 onto the site is considerable, they are essential to completing the WTC redevelopment. Moreover, their presence serves as very tangible evidence of the progress we continue to make in the reconstruction effort.
How will the Port Authority coordinate the utility and other infrastructure work for the reconstructed Greenwich Street, Fulton Street, and Cortlandt Way?
One of the great challenges in rebuilding the WTC stems from the fact that an unprecedented amount of construction is occurring within a single 16-acre site located in the heart of one of the densest, most active neighborhoods in New York City. With so many projects advancing simultaneously, careful coordination and logistics planning is essential for all construction activity on the site.
Key elements of the WTC rebuilding program are two newly constructed city streets -- Greenwich and Fulton -- and two newly constructed pedestrian ways -- Cortlandt and Dey. Each of these critical public infrastructure projects involves a unique set of challenges. Greenwich Street, for instance, is being constructed on top of the MTA’s active No. 1 subway line, which carries thousands of commuters a day through the middle of the WTC site.
So a key first step in constructing Greenwich Street is underpinning the No. 1 subway line and then excavating soil underneath the box while simultaneously constructing the underlying WTC infrastructure. Only with the underpinning complete can the construction of Greenwich Street proceed. The construction of the street, including utility placement, proceeds in phases, so portions are constructed and then used as staging areas as other portions progress. The sequencing of this “hop scotching” is carefully managed to ensure efficient completion of the work and is compatible with staging and access needs of adjacent projects on the site, such as the Memorial plaza.
Similarly, Fulton Street is built on top of the WTC Transportation Hub’s East-West Connector -- a retail-lined passageway extending through the site that forms a seamless below-grade circulation system linking the World Financial Center (WFC) and Battery Park City to the WTC complex. Not only does the Fulton Street construction depend on substantial completion of this corridor, it also is used for staging and access for other projects including 1 WTC and the Transportation Hub. As with Greenwich Street, the utility work is carefully planned and sequenced to permit access to adjacent projects while continuing to meet completion milestones.
As the above descriptions make clear, advancing the WTC Street utility and infrastructure work depends on the progress of other projects, and then entails significant coordination challenges. To meet those challenges, the Port Authority coordinates activities at several levels of increasing detail. First, individual project teams and contactors meet weekly to review staging plans and coordinate activities. When these meetings uncover potential conflicts, Port Authority project managers and contractors convene working sessions to find solutions that ensure work advances as quickly and safely as possible. There is also constant communication in the field to ensure construction continues to advance. By thinking about projects at various levels of detail and meeting continually, the Port Authority ensures that all projects on site maintain momentum.
What areas of construction have made faster-than-expected progress and why?
With the WTC assessment report, the Port Authority established aggressive but realistic schedules and budgets for each of its projects on the site. Through that assessment process we identified two opportunities to deliver projects earlier than anticipated. First, we re-sequenced the construction of the Transportation Hub’s below-grade mezzanine, building the roof first in a “deckover” approach. The Memorial plaza actually sits on top of this mezzanine roof structure, and building it first allows us to accelerate Memorial plaza construction so it can open for the 10-year anniversary of September 11th.
Second, we developed an innovative engineering solution to underpin the MTA’s No. 1 subway line, which bisects the WTC site. This approach calls for bracing the concrete subway tunnel -- commonly referred to as the “1 Box” -- and then excavating more than 100,000 cubic yards of dirt under the tunnel. As excavation advances, below-grade program space is constructed, an approach known as “top-down” construction. At the same time, work can begin on constructing the reinstated Greenwich Street on top of the 1 Box. As a result, this key piece of public infrastructure will be delivered much earlier than first anticipated.
In just slightly more than a year since the assessment, two other projects have made dramatic progress. In January 2009, we removed the Acrow Bridge ramp that spanned from street level down to the bedrock where the original twin towers were constructed, some 80 feet below grade. In the 11 months since then, more than 92 percent of Memorial structural steel has been installed and enough concrete poured that large portions of the plaza deck and the outlines of the reflecting pools are clearly visible. In fact, due to the level of progress made, family members of 9/11 victims were able to walk out onto the Memorial plaza for the first time during the September 2009 commemorative events. Memorial steel installation is slated to be nearly complete by the end of 2009.
The Port Authority has also developed a plan to accelerate construction of the Route 9A Pedestrian Underpass, a climate-controlled pedestrian corridor beneath the West Side Highway, which will serve the anticipated 100,000 people per day traveling between the WFC and the Transportation Hub. Under the previous plan, WFC master leaseholder Brookfield Properties was committed to design and construct a pavilion at the western terminus of the pedestrian underpass. Pavilion construction would have started only after completion of the underpass since limited staging area and access points permit only a single contractor to work in the area at any given time.
Working closely with Brookfield, the Port Authority developed a different approach where Brookfield performs a portion of the underpass work using the same contractor performing the pavilion construction. As a result, the building effort will be more efficient, saving a year on the combined schedule. Accelerating the opening of a permanent mid-block connection between the transit system and Battery Park City will significantly reduce travel times and improve the pedestrian experience for commuters, residents, and visitors -- one of the Port Authority’s overarching goals during the World Trade Center rebuilding.
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