Copper tubing system warms and cools bronze panels.



As monuments go, the National September 11 Memorial in lower Manhattan will remind many visitors of the Vietnam Veterans Memorial in Washington. The 9/11 Memorial is still under construction but it opened to visitors last September, shortly after the 10th anniversary of the terrorist attacks on the twin towers of the World Trade Center.

Just as the monument in Washington carries the names of the 58,272 service people who died or went missing during the Vietnam War, the 9/11 Memorial bears the names of 2,983 victims of the terrorist attacks in 2001 and 1993, including 11 unborn children. And, similar to the Vietnam Veterans Memorial, photos of the 9/11 Memorial really can’t do it justice. Both must be experienced on a personal level.

Each pool stands in a footprint of where the twin towers of the World Trade Center once stood. Photo credit: Bob Miodonski/Plumbing & Mechanical

I had the opportunity to visit the 9/11 Memorial in early June when I traveled to New York City on a business trip. After standing in line for 20 minutes or so on a Tuesday afternoon, and passing through a metal detector and security checkpoints, I walked up to the memorial but didn’t feel much emotion until I came close enough to read the names engraved there.

The last time I can remember having the same feeling was when I visited the Vietnam Veterans Memorial in the mid-1990s. Making the connection between the war or the terrorist attacks with individuals who were fathers, mothers, sons and daughters can be quite moving.

The 9/11 Memorial contains 12,000 sq. ft. of copper brackets and 14,000 ft. of copper tubing. Photo credit: Joe Woolhead

Touches encouraged

The 9/11 Memorial is separate from the Freedom Tower, which is being constructed on adjacent property. The memorial consists of two rectangular reflective pools located in the footprints where the twin towers once stood. The names are engraved on 152 connecting bronze panels on the perimeter of the pools.

The pools measure close to 1 acre each on the surface and 45 ft. deep, making them the base of North America’s largest manmade waterfall. Every minute, 50,000 gallons of recycled water cascade over the waterfall ledge and disappear down a square shaft at the center of each pool.

One difference from the Vietnam Veterans Memorial is that physical contact is encouraged at the 9/11 Memorial. Technology similar to that found in radiant systems will warm the bronze panels in the winter and cool them in the summer so visitors can pay their respects by tracing the names on the panels with their fingers.

Jaros Baum & Boles of New York and KC Fabrications of Gardiner, N.Y., designed the system, which consists of 12,000 ft. of copper brackets and 14,000 ft. of copper piping, according to the Copper Development Association. Christopher Powers, founder of KC Fabrications, assisted JB&B with the system’s design to ensure it would work with the memorial’s bronze parapets.

“We worked together to design and assemble a back-mounted tube system that could work within the parapets and nameplate system,” Powers says. “A network of copper pipes circulates glycol behind the parapets to heat and cool the bronze panels.”

Half-inch diameter copper tubing makes this heating and cooling possible. Tubing is fastened behind each panel in a looping system down into the pedestal, thereby controlling the temperature of the touch surfaces. The designers say they chose copper as the preferred material for this project because of its corrosion resistance, high levels of heat transfer, durability, workability and reliability. The mechanical contractor who installed the piping declined to be interviewed for this article.

Ronaldo Vega, the memorial’s director of design and construction, says that human interaction with the memorial is vital for every visitor’s experience.  Keeping the panels between 40° and 70° F is essential for the memorial’s success because if the panels are too hot or too cold, the memorial loses the ability for people to interact with it.

“The bronze panels are the first thing people see, the first thing they touch and their first contact with the memorial,” Vega says. “We want people to be able to connect with it. The memorial almost becomes like a baptismal setting. Here folks can dip their hand in the water beneath the panel and leave a handprint instead of a stone or rock.”

Copper tubing is fastened in a looping system beneath the bronze panels, thereby controlling the temperature of the touch surfaces. Photo credit: Amy Dreher

LEED-certified

The project, which is Gold LEED-certified, uses recycled water not only for the waterfalls but also to irrigate the nearly 400 trees that have been planted on site.

“The system is extremely efficient,” Vega says. “It was designed to minimize water and energy costs.”

CDA President Andy Kireta Sr. says about 91 tons of bronze in the panels and miles of brackets and tubing make copper and its alloys important contributors to the 9/11 Memorial.

“From the piping to the panels, copper plays a key role in making this memorial truly unforgettable,” says Kireta, who also visited the site. “To be here and to see it in person is a remarkable experience. I hope this magnificent memorial can serve as a lasting tribute and help heal the families who were directly affected, as well as our country.”

People who visit the 9/11 Memorial should be aware that they need passes to enter the grounds, at least until construction is finished. Passes can be downloaded at www.911memorial.org/visitor-passes.

The passes are free, but donations are encouraged. Visitors also can make donations at the memorial.