In a preliminary report this month, the agency, the National Institute of Standards and Technology (NIST), an arm of the U.S. Commerce Department, listed firefighter lifts as a possible recommendation on how to make tall buildings safer.
Building codes in Europe and most of Asia require firefighter lifts, though specific requirements differ. In both places, firefighter elevators are located near fire stairs, in a part of the building where the air is pressurized to keep smoke out. The shafts are water resistant to prevent damage from sprinklers and fire hoses. The elevators' mechanical and electrical systems are rated to work in wet conditions. The doors have to be fire-rated.
European codes require a small dedicated elevator for use only during emergencies. They're large enough to carry three firefighters with equipment. In most Asian countries, including China, the elevators tend to be larger and can also be used during normal operation for freight.
Critics of the European model say the elevators are too small, and because they aren't in use all the time, might fall into disrepair. Detractors of the Asian model, meantime, say because they are in use for freight service, they could be blocked with goods when an emergency happens.
Current U.S. practice allows firefighters to use elevators to reach the fire and evacuate disabled people. But the elevators don't have special protection like in Europe and Asia.
At least one building in the U.S. will have something akin to a firefighter lift, though the building's architect, Skidmore Owings & Merrill, is not calling it that. The Freedom Tower, the skyscraper that is planned to rise next to where the Twin Towers fell, will use a system similar to the Asian model, where a set of service elevators would be placed in a pressurized fire-protected lobby near the fire stairs.
But the Freedom Tower could be the only U.S. building with such elevators. NIST's recommendations are advisory only. Model codes on elevators in high rises are written by a coalition of builders, engineers, architects and fire-safety professionals. It's then up to local governments to adopt or amend the model codes.
Also in the way of adoption will be the price tag. In addition to the elevator itself, there's the loss of usable square footage, as well as maintenance and other costs.
The final NIST study, which also examines why the towers collapsed, is expected to focus on improving how firefighters get into buildings, and how occupants, especially disabled ones, get out. Of the 212 elevators in the Twin Towers, only two worked after the planes hijacked by terrorists hit the New York skyscrapers on Sept. 11, 2001. It took firefighters more than an hour to climb to around the 30th floor of the North Tower.
