Lynda Tollner is a program director in the World Trade Center Construction Department with design and construction responsibilities for One World Trade Center.
Ms. Tollner has more than 25 years of experience in project management and structural engineering and has worked for the Port Authority for seven years. In the past, she has managed design and construction of a variety of commercial, institutional and transportation facilities including projects at LaGuardia and Newark Liberty International airports and the Port Authority's current headquarters at 225/233 Park Avenue South.
One World Trade Center is scheduled to open in 2013.
Q. Will there be retail below One World Trade Center? – Jamal, Brooklyn, N.Y.
A. Retail is a critical component of the rebuilding effort, and we anticipate that there will be about 39,000 square feet of retail located in or around One World Trade Center when the project is complete.
Q. I am following the construction of this project and find it remarkable. Regarding the concrete pour that recently occurred for the east plaza, a sunken large round area can be seen, and I wondered what the purpose of this was. Is it the intention that the Koenig Sphere from the original plaza will be placed there? – Joe, Nottingham, N.Y.
A. Joe, as you may have seen in the designs for One World Trade Center, the street-level portion around the tower will be a tree-lined plaza. The sunken large round area that you refer to will serve as a planter for landscaping elements that will beautify the plaza area.
Q. I've been following the construction of One World Trade Center and was wondering if the cores will always be built staggered as they are now, or is the south core going to wait on the north core to catch up and rise together? Also, will there be more tower cranes installed at the site? – Anthony, Scarsdale, N.Y.
A. As you may have noticed, we poured another level of the north core last week and we anticipate that the north core will catch up to the south core in August. By the end of this quarter, we expect to install steel on top of the north core and jump the north tower crane up 189 feet above street level. Ultimately, we expect there will be three tower cranes on this project.
Q. I would like to know when more of the steel core is going to be built and when we are going to start seeing the outer perimeter columns going up? – Jason, Miami, FL
A. As I mentioned in a previous inquiry, we expect to install steel above the north core during this summer, and this fall, you'll see jumbo columns being installed around the tower's perimeter.
Q. I was wondering when the actual steel perimeter will start rising? From my vantage point, it looks like there are still basement areas needing to come up to street level on the north as well as the west side. Perhaps by September? – Joseph, Cambridge, MA
A. An excellent observation, Joseph. Not all of the below-ground areas around One World Trade Center need to be completed to begin the erection of the tower's jumbo perimeter steel columns. A crawler crane will be mobilized on the recently poured southeast slab at street level to assist in the erection of the first perimeter steel columns. We expect to begin installation of these jumbo columns this fall.
Q. What is taking One World Trade Center so long to get built? – Richard, New York, N.Y.
A. Richard, what most people don't realize is the extent of work that needed to be done to build the underground portions of the tower, which stretch 80 feet below ground. There is approximately 500,000 square feet of space that needed to be built below ground before we can begin to install above-ground steel columns. We also are building the largest office tower in the United States with the PATH system – which operates 24 hours a day, seven days a week – running through the tower's footprint, which adds an extra layer of complexity to an already complex construction job.
Q. I would like to know when it will be possible to see the skeleton of One World Trade Center built. So far, only the basement has been done, and the north base is still being poured that is directly over the PATH tracks. When are we going to be able to see the actual lobby, windows and walls? – Boris, Montreal, CT
A. Boris, the above ground steel framing for One World Trade Center should begin in the fall. The exterior skin of the building, or curtain wall, will begin next summer. The lobby finishes will start later in the construction process, as the project is nearing completion.
Q. How high will One World Trade Center's rooftop be without the parapet? When will the superstructure begin rising for One World Trade Center now that the lobby floor is at grade level? How many observation decks will the tower have? When is the tower expected to top out? – Monique, Portland, ME
A. The rooftop structural steel will top out at 1,368 feet above the lobby level in the fall of 2011. This does not include the 408-foot antenna structure, which will bring the total height of the building to 1,776 feet. The building will have a two-level observation deck on the 100th and 101st floors. The installation of perimeter steel will begin this fall.