Capitol Challenge

The following article appeared in the November/December, 2000,  issue of NFPA Journal.
©2000 NFPA Journal. Used with permission

The United States Capitol, one of the most enduring symbols of the U.S. government, is rich in history and serves as a museum for some of our nation’s most important works of art. Along with this cultural heritage, it also houses the Senate and House of Representatives. Combining a historical building, a museum, and an office building into one structure provides some significant challenges when designing and installing fire protection.

Construction on the United States Capitol began in 1793, and the Congress, the Supreme Court, the Library of Congress, and the courts of the District of Columbia occupied the north wing in 1800. Construction stopped until additional funding in 1803 allowed the government to hire architect Benjamin Latrobe. As work began on the south wing, the north wing, which was already falling into disrepair, needed renovations. This work was only partially completed by 1811, when funding became scarce because of the impending war with Great Britain.

However, even then fire safety was in the forefront, according to Bill Allen, architectural historian for the Architect of the Capitol.

“[Being] fireproof and solid were two of the driving forces,” says Allen. “Latrobe was using construction methods involving masonry arches and domes. Not only were these architecturally pleasing, they were some of the best-known fire safe construction methods of the time.”

Latrobe’s good sense was put to the test in 1814 when the British set fire to the Capitol and the White House during the War of 1812. According to Allen, the fire heavily damaged the White House, which was built primarily of wood. The Capitol building, on the other hand,  suffered less fire damage.

After the war, Charles Bullfinch, a Boston architect, began to oversee the construction. By 1826, 33 years after construction originally started, the Capitol was complete, sporting a copper-covered wooden dome over the center of the building.

By 1851, however, the government was outgrowing the building and expansion started on the north and south wings. After the renovation, the dome wasn’t proportional to the length of the wings and was also considered a fire hazard. In 1856, the old dome was removed, and a “fireproof” cast-iron dome was put in its place.

The Capitol building, which itself is considered a historical work of art, is home to numerous priceless works of art that document important events in U.S. history. The Rotunda is home to the Declaration of Independence, as well as three paintings by John Trumbull, which were put in place between 1819 and 1824. Between 1840 and 1855, additional paintings were added, and in 1865, Constantino Brumidi painted “The Apotheosis of Washington” on the dome’s canopy. Other works of art in the Rotunda include statues and busts of presidents, including George Washington, Abraham Lincoln, Ulysses Grant, and Thomas Jefferson.

Fire protection

“One of the unique challenges is the ability to design and install fixed detection or suppression systems while not destroying the architectural fabric of the building,” says Ken Lauziere, P.E., head of the Fire Protection Engineering Division for the Architect of the Capitol (AOC). Lauziere, who’s been designing fire protection systems for the Capitol for 22 years, has had a lot of experience overcoming these challenges.

Balancing the needs of fire protection against preserving the historical heritage is an ongoing effort in the Capitol.

“We use a lot of creative thinking and creative use of existing technologies,” says Lauziere. “How do you install wiring without it destroying wall murals painted in the 1860s, for instance?” Some of the methods used are unique. Take, for example, some special pieces of art that merit different suppression systems. The cases that hold the Maintz Bible and other valuable works use gaseous agents and cross-zoned smoke detection. These systems currently use Halon 1301, although newer systems are using environmentally compatible agents. Sprinklers back up these gaseous agent systems.

It’s also important to protect the 30,000 daily visitors and the 35,000 Capitol employees. Any interruptions to sessions of Congress are taken very seriously, so it’s vital to identify potential fires early and initiate an appropriate response.

Once a fire protection need is identified, the AOC’s office puts together a cost estimate. These requests must go through a series of hearings before a subcommittee responsible for legislative branch appropriations. If the committee agrees, the funding for the design and installation is available two years later.

A major hurdle for the AOC is scheduling the work. Each congressional representative and senator’s office is “owned” by the state he or she represents, and the AOC can only do work with the occupant’s permission. Furthermore, much of the work is done at night or while Congress is in recess to minimize interruption.

When work in a particular office is being done, a photograph is taken immediately before the work begins. Then, when the crew has finished for the night, it uses the photograph as a guide to replace all the furnishings to their original positions.

Photographs are also taken of the work in progress. After the workers channel a wall through which they’re going to run wiring, for example, they take a picture. Later, if an office needs to be modified, they can check to see if the work will affect any wiring.

More logistical problems come from having to do the work in small sections.

“We can’t do a whole wing, and go left to right. We have to do one room at a time, channel it, wire it, and then do the next room,” says Bob Creger, supervisor field representative for the Construction Branch of the AOC.

Smoke detection

According to Creger, the building has various types of smoke detection systems. Approximately 90 percent of the systems use conventional smoke detectors, while 8 percent use beam detectors, and the remaining 2 percent use air-sampling systems.

Air-sampling systems are installed in some of the rooms that contain artwork. In one of the hearing rooms where Brumidi painted the walls, for example, the AOC installed piping up a doorway through which they draw air samples. To complete the installation, the floor tiles had to be removed and the piping run to a sampling device in the basement. The piping was so well concealed that the committee chairman couldn’t even find the smoke detection in the room.

Lauziere also uses projected beam smoke detection. By installing the equipment on the tops of column caps, where it can’t be seen from below, they’re able to cover vast areas with minimal detection. This protection scheme is typically used in the large hearing rooms, most of the corridors, and in the great halls. In the Rotunda, the detectors are at three different levels and calibrated to detect obstruction levels of 3 to 6 percent per foot.

Currently, the AOC is providing smoke detection in the Capitol dome itself, which is actually two separate structures, one inside the other. Within this interstitial space, the AOC is installing air-sampling tubes to draw in air and carry it to a sampling location. An air sampling laser smoke detector then tests the air for smoke particles.

While this system could detect a small fire in a wastebasket on the floor of the Rotunda, Lauziere says that the a fire would probably be detected even sooner by other means. Such means include Capitol police officers who are positioned throughout the building when the Capitol is open. Furthermore, an extensive network of video cameras monitors many areas of the building, helping to spot fires in their early stages.

Because of the design of the building, the second floor is the most challenging to retrofit, according to Creger. If fire alarm systems are installed on the first or third floors, wiring can be run in the basement or the attic. Since this isn’t possible on the second floor, more creative measures have to be used.

Sprinklers

Recently, there’s been a push to install sprinkler systems throughout the Capitol complex. Lauziere has used such techniques as designing almost every sprinkler system as a looped system.

“The advantage is that this not only provides us with redundancy, but we’re able to use a smaller pipe diameter, too,” he says. The AOC also makes extensive use of copper piping in the sprinkler systems because of the pipe’s smoother flow characteristics. Copper piping is easier to work with and conceal, as well.

Installing sprinklers so that they’re not in plain view is another significant challenge. One common technique is placing a sprinkler in the middle of a decorative rosette. However, before any workers drill into the middle of an actual rosette, they use practice rosettes to demonstrate that they can do the work without causing damage. In some rooms, they’ve installed the piping along wall molding and painted it to blend in. For consistency, they’ve even installed piping along the room’s other three walls.

“Sprinklers in some of the buildings are so well concealed that without drawings, I can’t find them,” says Lauziere.

Workers have also had to use unusual techniques to drill holes. In one case, Lauziere had the contractor cut a hole by running the saw in reverse to wear away the plaster instead of cutting it, which would have caused more damage.

“The contractor thought I was crazy,” says Lauziere.

Since the occupancy use of an area can change frequently, each of the systems is designed for ordinary Group II sprinkler densities. By doing so, Lauziere knows that the sprinkler system can provide protection for any future use.

Lauziere has also had to install sprinklers contrary to their UL listing. For example, he’s placed quick response sprinklers lower than their listing calls for. Testing at the National Institute of Standard and Technology has shown that doing so causes the quick response sprinkler to react like a standard response sprinkler, which was his intended goal. At a recent fire in one of the house office buildings, “everything worked as it was supposed to,” says Lauziere. “This keeps validating that the systems are working.”

Lauziere has conducted live burns to test some of the designs, and he uses computer modeling, as well.

Fire alarms and egress issues

In 1980, the AOC decided to put in a slow whoop signal fire alarm system. The main reason was that it emits a distinctive sound that only the alarm system would make. The system can also reproduce voices, so it can give directions. At first, the system used taped messages but now uses digitized messages. All the fire control rooms and the police division offices can also give live direction through microphone input.

One unique design feature in the fire alarm system is that no device can activate the audible devices. Instead, an alarm signal is transmitted to one of the constantly monitored locations in the complex, and an on-duty Capitol police officer is immediately dispatched to evaluate the situation. This procedure avoids malicious activations of the system while Congress is in session. This method works because police constantly staff the building, which has a significant number of video cameras.

 One of the reasons egress design is a challenge, says Lauziere, is because stairways were converted to elevator shafts when the building was retrofitted with elevators, and alternative egress routes weren’t created to make up for the lack of stairs. To help correct some of the deficiencies, the AOC has sometimes had to come up with unorthodox solutions. For example, they’re currently converting an exterior window into a door.

Because of the Capitol’s design, it’s not possible to compartmentalize the building. If a general evacuation is necessary, the entire building is evacuated at the same time.

The Capitol police are an integral part of the evacuation process. Since they’re required to conduct evacuation drills for each building under their jurisdiction, they conduct drills at least 14 times a year. This, according to Lauziere, has provided them with a great deal of experience in managing mass evacuations.

What to do?

When undertaking any fire protection project in a historic building, putting together a team composed of representatives from all of the different disciplines is critical.

“Definitely have a historic preservationist involved,” says Allen.

Dr. John M. Watts, Jr., a member of the NFPA 914, Recommended Practice for Fire Protection in Historic Structures, committee, adds, “One of the biggest issues is establishing communication between the code official or fire safety consultant and the historic preservation people and interests.”

Dr. Barbara Wolanin, the curator for the Capitol, agrees.

“Better project coordination in the beginning is far better than having to make changes at the last minute,” she says.

When bringing these two groups together, Watts says that it might appear at first that they’re opposed to one another. However, “both groups are trying to preserve and protect the building, one from fire and the other from all the other types of threats that historic buildings may be exposed to. Remembering that sometimes helps to get the communications going.”

NFPA 914 is currently a guide, but at the NFPA 2000 Fall Education Conference, the membership is going to vote on making it a standard.

“NFPA 914 tries to identify a process of establishing appropriate fire safety in historic buildings,” says Watts, who is one of NFPA 914’s former chairs. NFPA 914 includes information on fire experience in historic buildings, identification and evaluation of existing conditions, planning and design, fire protection and safe practices in the construction phase, and operations and maintenance.

NFPA 914 can serve as a bridge between the code official and the historic preservationist. While both want to preserve historic buildings from damage, the two disciplines may seem to differ on how to go about this. The historic preservationist doesn’t want to do any work that will alter the historic character of the building, while “the code official says it has to conform with every other kind of building and might not appreciate the distinctiveness of the cultural heritage,” says Watts. It’s important to be creative and not apply a cookie-cutter approach to fire safety in historic buildings.

Ensuring that fire doesn’t damage any of our nation’s historical treasures is an ongoing and complex challenge. Implementing fire protection plans in such a way as not to damage irreplaceable works of art or the building itself provides additional challenges to the engineers and workers in the Capitol. Through the creative use of new and existing technology, however, the safety of such a significant national landmark and that of the workers and visitors is being improved.