Thomas J. O'Connor is a senior engineer of construction for the World Trade Center Construction Department and is responsible for managing the construction of the National September 11 Memorial & Museum.
Mr. O'Connor has nearly 30 years of experience in project management and engineering construction activities, including the restoration of the temporary World Trade Center PATH Station and major construction projects at John F. Kennedy International and LaGuardia airports.
Note: More than 40 questions were submitted regarding construction progress on the 9/11 Memorial & Museum. Repetitive or similar questions were folding into one.
Q. The renderings for the Memorial pools show their surfaces as being a very tranquil light blue color, but in the most recent photos and videos of the pools, the pools appear to have a very dark and blackish color. Is this likely to be the final color of the pools, or will the base of the pool be painted to give it the light blue color? – Ryan, Baton Rouge, LA
A. Ryan, the granite installed on the walls of the reflecting pools is dark black with a gray bottom. This is the color that visitors will see when they visit the Memorial.
Q. The top of the PATH Station arches appear to be at different levels. Will the Memorial Plaza and Fulton Street also be at different levels? – John, Los Angeles, Calif.
A. Both the Memorial Plaza and Fulton Street will be on the same level.
Q. Will the Memorial have any open areas of grass and paths to walk around and see the towers above all of the trees, or will it be covered by the 400 trees? – Michael, East Brunswick, N.J.
A. As you can see from the renderings on our Web site – www.wtcprogress.com – the Memorial Plaza consists of numerous paths interspersed with the trees that will provide visitors with an awe-inspiring view of the surrounding towers and WTC Transportation Hub.
Q. Since it is so cold in New York, how will you keep the Memorial pools from freezing? – Jeff, Jacksonville, FL
A. Great question. The waterfalls in the reflecting pools will operate throughout the winter months without the risk of freezing because of steam exchanges that the water will run through as it recirculates.
Q. Will the Memorial and Museum be ready for the 10th anniversary? – Michael, Smithtown, N.Y.
A. The Memorial will open for the 10th anniversary, and will remain open after that date. This is our top priority and all of our construction activities have focused on meeting this commitment. The museum will open up afterwards. In our 2008 assessment, we committed to opening the museum in the second quarter of 2013, but we are now looking to beat that date because of all of the recent progress made.
Q. I was wondering if they have started cladding on the pavilion, and if not, when is this work going to start? – Jeffrey, Massillon, Ohio
A. Cladding has begun. You can see pictures of our progress at www.wtcprogress.com.
Q. Where is the water for the Memorial pools coming from, and is there a strategy to keep the water from evaporating? – Joseph, Minneapolis, MN
A. The water that will be filling the Memorial reflecting pools is New York City water. The water circulation system we have installed for each pool is designed to provide sufficient replacement water to make up for loss due to evaporation.
Q. Approximately how much dirt will be used to complete the project? Also, how much stone will be used to create the plaza and paths? – Michael, East Brunswick, N.J.
A. About 18,000 cubic yards of dirt – enough to fill five Olympic swimming pools – will be used to complete the Memorial Plaza. Approximately 128,000 square feet of stone – which would cover more than two football fields – will be used to create the plaza and paths.
Q. What are the two buildings on the left side of the Memorial and what are they used for? – Jesus, Peoria, AZ
A. The two buildings located on the left side of the Memorial are ventilation structures. They will provide ventilation to the below grade spaces, including the Memorial Museum and the WTC Transportation Hub.
Q. Are the Memorial pools as large as the Twin Towers used to be, and can the water run in the winter? – Robert, fair Haven, VT
A. The Memorial reflecting pools are slightly smaller than the dimensions of the footprints for each of the Twin Towers. Each of the pools will be nearly one-acre in size and 30 feet deep. As I mentioned previously, the Memorial pools will continue to run throughout the winter months.
Q. Is there going to be problems in the fall with leaves falling into and clogging the reflecting pools? If so, how are they going to resolve it? – Michael, New York, NY
A. To deal with the leaves and other debris that may get into the pools, we have installed debris screens located at the bottom of each pool to catch and filter out these items.
Q. Is there a date when the south pool will be tested? And when will the Memorial Plaza walkways be tested and completed? – Lisa, New York, NY
A. We will complete the construction and testing of the south pool by second quarter of this year. The walkways will be completed by third quarter 2011 in time for the 10th anniversary.
Q. In news reports, it was said that the Memorial will be open on the 10th anniversary, and will then close until other buildings are nearing completion. Is this true? – Dominic, Grants, NM
A. The Memorial Plaza will open for the 10th anniversary, and will remain open thereafter. There will be controlled public access after that date during the construction period that will follow as the towers and Transportation Hub rise around it.
Q. How will construction be affected when pedestrians are on the 9/11 Memorial Plaza? – Jordan, Valencia, CA
A. It will be a significant logistical challenge but all visitors will be isolated and protected from surrounding construction, with construction progress around it.
Q. How long will it take to install all of the glass around the 9/11 Memorial pavilion? – Robert, Roselle, IL
A. The Pavilion cladding is anticipated to be complete by the third quarter of 2011, in time for the 10th anniversary.
Q. I know the victims' names will be lit at night, but will the waterfalls themselves be lit at night also? – Steven, San Diego, CA
A. Yes, the bottom of each waterfall is lined with lights, which will illuminate the waterfall of each pool at night.