HIGH-RISE FIRE SPREAD: LEARN FROM THE PAST

HIGH-RISE FIRE SPREAD: LEARN FROM THE PAST

New York City currently has more than 1,000 buildings of 100 feet or more in height, excluding residential or hotels. The first major high-rise fire and million-dollar loss in New York City occurred in the Home Insurance Company building on December 4, 1898. Since then, the experience and knowledge gained from these fires has provided the opportunity to study the problem in depth. Unfortunately, much of the information gathered over the years appears to have been forgotten or dismissed as outdated. The time has come to revive the material gathered from past experiences and use it to assist your high-rise suppression and protection efforts.

The protected steel-frame construction of the Home Insurance Building was considered the most advanced design of the time. The fire originated in an adjacent five-story, nonfireproof building and quickly involved the entire structure. The highrise windows overlooking the fire building were regular unprotected glass, and they quickly failed. The failure of the windows allowed the fire to extend from the 6th to the 16th floor of the building. Subsequently the NYC building code was amended to require wired glass w ith a 3/4-hour fireresistive rating.

(Editor’s Note: “Fireproofing” was the general term given to the practice of insulating the steel structural members with tile, plaster, or concrete. “Fire resistive” is a more accurate term for such construction techniques and refers to a building’s resistance to collapse under fire conditions and resistance to vertical and horizontal spread. Refer to Frank Brannigan’s Building Construction for the Fire Service, Chapter 11.)

On April 22, 1908, the New York City Fire Department received an alarm for the 12-story Parker Building, representative of fireproof buildings occupied for mercantile and light manufacturing purposes in New York City. Upon arrival the firefighters found both the fifth and sixth floors involved in fire and heavily charged with smoke. Fire spread quickly up the building’s open stairways. Electrical conduit placed inside tile fireproofing expanded, pulling the tile off the columns and exposing the columns to the extending fire. Structural integrity was severely compromised and the building collapsed, killing several firefighters.

The New York Board of Fire Underwriters was asked to investigate and determine the cause and spread of the fire. They concluded that the large amount of combustible material in the Parker Building, its large open areas, inadequately protected stair and elevator shafts, and lack of early w arning devices furnished conditions that permitted the rapid spread of fire before the fire department’s arrival.

The board strongly recommended the establishment and enforcement of fire safeguards. These included more effective use of fireproofing materials and the use of automatic sprinklers, especially in high-rise buildings used to store large quantities of combustible material.

The Parker Building fire caused a stir because a supposedly “fireproof” building had failed so rapidly, yet there was no immediate reaction in the w ay of code amendment.

On January 9, 1912, a fire was reported in the Equitable Life Assurance Building in lower Manhattan. Firefighters arrived at this eight-story building in the early morning hours. The fire was not declared under control until the late afternoon, hours after the building had collapsed. Again, large unprotected, undivided vertical and horizontal openings, coupled with heavy fire loading, produced rapid fire spread. Once the fire gained headway into the upper floors, fire department operations became ineffective due to the absence of standpipes and smokeproof stair towers.

SPREAD: LEARN FROM THE PAST

The Triangle Shirtwaist fire in 1911 took 146 lives. The fire occurred in the upper three stories of the Asch Building, a factory loft building that housed several manufacturers. The fire spread rapidly through the vast amount of shirtwaist material, and the lack of adequate exits forced manyvoung women to jump to their deaths below. Following the fire, the New York State Labor Law instituted the requirement that sprinklers be installed in factories of more than seven stories in height.

This fire, like that of the Equitable Building and Barker Building, paved the way for a number of tests on fireresistive construction, including ASTM F-119, the National Bureau of Standards test that is still used as a standard for fire resistance.

Based on these fires, the New York and the National Board of Underwriters recommended that any building more than 50-feet or four-stories high be equipped with some or all of the following fire protection features: automatic sprinklers, smokeproof stair towers with standpipe equipment, one or more interior fire walls, and ample stairways and other approved means of exits. Fire doors should be used as corridor partitions in every office building, and any glass should be wired for reinforcement. Single offices containing large areas should be subdivided by fire partitions intended to retard the fire spread.

Moving to more recent history, on August 5, 1970, occupants of One New York Plaza pulled a fire alarm box in response to a fire on the 33rd floor. The alarm boxes were not connected to a central station or the fire department so they produced no results. A guard in an adjoining building called in the first registered alarm eight minutes after the alarm box was pulled.

When the fire department arrived, the 33rd and 34th floors were raging infernos. Smoke and heat were so intense that firefighters could stay on the floor for only short periods of time. It took five hours to control the fire, and the building sustained S10 million worth of damages. The rapid spread of fire was caused by the common ceiling plenum in the HVAC system, exterior curtain wall construction. Q-deck floors with embedded raceways, and heavy fireloading. The delayed alarm was another major contributing factor.

In the early morning of Friday, February 14, 1975 a fire was reported from the 1 10-storv North Tower of One World Trade Center. The fire involved the ninth to 19th floors. Firehad spread through the common airhandling plenum in the ceiling. Window glass failed, which caused autoexposure of upper floors. The main cause of fire spread was determined to have been through openings around cables in telephone closets that were not fire-stopped. The telephone closets had louvered doors and contained cable insulated with polyethylene and polyvinyl chloride. These cables passed through ceiling openings of 12″ by 18″ to the closet above and through holes in walls to other closets on the same floor.

This building had unique regulations restricting the combustibility of furnishings, drapers, curtains, and carpeting. While these restrictions did not eliminate combustible furnishings, they limited extremely rapid extension that could have worsened the situation.

These fires and many others have provided a list of basic methods to reduce fire loss and provide life safety:

  • Automatic sprinklers provide important and necessary fire protection. When properly installed and maintained they are the most effective means of limiting smoke generation and fire spread.
  • Openings between floors, whether access stairs, cable openings, or the HVAC system, must be protected with fire-resistive barriers.
  • Reducing the amount of combustible materials available to burn and controlling the types of combustible furnishings allowed in the building will positively impact the fire spread problem.
  • Farly alarm is important both to help fire personnel control the fire spread and to ensure the safety of the occupants. Modern technology has provided the means to detect fires in the incipient stage, yet we still find the alarm being transmitted by people from outside the fire building.
  • Large open areas allow fire to spread freely throughout a structure. Compartmentation and fire barriers are necessary. The current trend toward open office design invites rapid fire spread.
  • Wire glass provides protection from external fires and autoexposure. Today’s technology should be able to produce a wire glass or substitute that would satisfy asthctic requirements while restricting fire spread.

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