Not worth repeating?

Try as we might, fire protection engineers are often victims of a truism often applied to the fire service in the times before their great awakening. Awakening to mana of incident command,  exterior attack, and spending most of their time following ambulances around with a million dollar apparatus. It is ,“a hundred years of tradition unhampered by progress.” 

Though we promote performance based design (PBD) as "the way," One allure of PBD is in its forward-looking approach to problem solving. The ideal implied in the PBD method is a means to identify hazards and for the engineering to mitigate them without being chained to the old way of applying experience to solve the problem.

And while many (even myself) often decry the heavy-handedness of prescriptive codes, their one-size-fits-all approach, the extra expense involved in doing it by the book, there is one thing that is irrefutable.  A key reason they work is that they have been built on a mountain of misery or lessons learned from tragic fires. This why it is important for those applying prescriptive codes and standards to be students of the codes; to make an effort to understand the intent behind a given provision in the code. We in the code weenie community often lose sight of the importance of the past. The problem is we have done our job too well. 

We just do not have that many “good” fires any more to learn from. In addition to the knowledge gained from the lessons learned, the “good” fire serves to re-energize the passion needed to sustain a mission as noble as protecting life and property from fire.We are indeed fortunate in our country that we now have so few “good fires.”  While we watch amazing video of high-rise buildings in other countries turning into roman candles, we can with some confidence be comfortable in the knowledge that certain things are not likely to occur here. That was not always the case.

February 23 marked the 25th anniversary of the One Meridian Plaza fire, one of those “good fires." The following comes from “Fire Investigation Report, One Meridian Plaza Philadelphia, Pennsylvania Three Fire Fighter Fatalities" published on February 23, 1991 by Thomas J. Klem. The fire department received the initial alarm from a person located outside the building just before 8:30 p.m. Upon arrival at One Meridian Plaza, the firefighters observed heavy smoke at the mid-height of the building. Firefighters soon observed flames extending from one window and exposing the floor above. A thick, dark column of smoke was seen extending up the building’s facade toward the roof, and smoke was also beginning to vent from several additional points along the north side of the floor where the fire started. The fire spread from the floor of origin, to the 22nd floor, to the 29th floor. One Meridian was a 38-story high rise building built in 1973. It was originally unsprinklered. At the time of the fire, the building was being retrofitted with an automatic sprinkler system. The building was located at 1414 South Penn Square, Philadelphia, Pennsylvania. It faced city hall and its famous statue of William Penn.The NFPA Fire Investigation Report 1 cited the following major factors contributing to the loss of life and the severity of the fire:

  • The lack of automatic fire sprinklers on the floor of fire origin
  • The lack of an automatic early detection system
  • Inadequate pressures for fire attack hose lines due to the improper settings of the standpipe pressure regulating valves
  • The unimpeded growth and spread of the fire on the 22nd floor
  • The early loss of the main electrical service and the emergency power to the building, including the loss of elevator service due to a breach in the electric room enclosure on the floor of origin
  • The improper storage and handling of linseed soaked rags and other associated combustibles

The fire started at 8:23 p.m. on a Saturday evening. Security received an alarm of an activated smoke detector on the 22nd floor. The fire investigation revealed that the fire originated on the 22nd floor in a private office located on the north side of the building. The cause was determined to be spontaneous ignition of linseed-soaked rags used for restoring and cleaning wood paneling within the floor area.Very early in the fire, primary power to the building was lost. Fire entered an electrical room on the 22nd floor at approximately 8:37 p.m. causing loss of the two main building electrical feeds that ran up through the building.  

In 1988, the existing manual dry standpipe system was converted to an automatic wet standpipe system. Hose valves were equipped with pressure regulating valves. During early fire operations, firefighters reported that hose stream flows were severely weak. The fire investigation revealed that the settings on the PRVs were set too low to allow decent hose stream performance. Though field adjustable PRV hose valves were installed, the adjustment required the use of a special tool. During the fire, an employee of the sprinkler contractor working on the sprinkler system assisted the fire department by adjusting several of the PRV, with that special tool, to improve hose stream flows. Without power for the fire pumps, the fire department supplied water through fire department connections. In response to the issues brought to light by this fire, in May 1991, NFPA issued Alert Bulletin 91-3 Pressure Regulating Devices in Standpipe Systems. 

The bulletin recommended fire departments to check every standpipe-equipped building within their jurisdiction for the presence of pressure regulating devices. Further, they should become thoroughly familiar with the function of the various pressure-regulating devices. If they find such devices, they should immediately contact the building owner and verify that the devices have been properly selected, installed and adjusted to deliver the pressures and flows needed for firefighting purposes. Information on the inspection, testing and maintenance of standpipe systems is contained in NFPA 14A. NFPA 14. At the time, the standard for ITM of standpipe systems and has since been replaced by NFPA 25.

Subsequent changes to NFPA 14 and 14A included requirements  that hose valves equipped with PRV’s  be tested to confirm adequate flow and pressures during system acceptance and as part of ITM. Early in the fire, three firefighters were sent into the center stairway on the 22nd floor with instruction to open the roof door to vent the stairs. These firefighters reported they were in trouble, and a major rescue effort was launched to find them. They reported leaving the stairway on the 30th floor, so rescue efforts were focused on the 30th floor and above. Unfortunately, they actually left the stairway on the 28th floor, and it was not until 2:00 a.m. Sunday morning that their bodies were recovered.

The investigation report indicated that stairway identification signage was provided. At the time, the building was undergoing a sprinkler retrofit. The original building had sprinklers in the three basement levels. At the time, fire sprinklers had been installed on the floors 30, 31, 34 and 35. With the help of improved hose streams, firefighters had managed to control the fires on floors 21, 22, 23 and 24 but could not stop the spread to the upper floors. At 7:00 a.m. Sunday morning, fearing collapse of the structure, firefighters were removed from the building. The fire continued to spread fully burning out on floors 25 through 29. During this 18-hour fire, 12 alarms were struck by the fire department involving hundreds of firefighters. With the fire department pumping through connections to the sprinkler system, the  fire’s progress was stopped at the 30th floor by a total of 10 operating sprinklers. 

In 1991, the U.S. had recognized the importance of sprinklers protection for high rise buildings. New high rises at the time were being provided with sprinkler protection, but there are still many older high rise buildings that are not. A key lesson learned from this fire, as alluded to in the investigation report, is that unsprinklered high-rise buildings present challenges to even the most modern and well-equipped fire departments. Sprinklers are essential to firefighter safety in high-rise buildings. About 45 minutes into the 1993 movie “Philadelphia” starring Tom Hanks and Denzel Washington, a helicopter-mounted camera takes a sweeping circular view around the statue of William Penn. If you look closely you will see a high-rise building come into view with plywood covering many openings on several floors, One Meridian Plaza. 

In addition to the terrible loss of three firefighters, the property loss and loss of business was tremendous. One Meridian Plaza, deemed structurally unstable, stood as a horrible reminder to Philadelphians until it was demolished in 1999. Like those unaware of the Beer Hall Putsch with its similarity to modern day events, “Those who cannot remember the past are condemned to repeat it.”

 The full investigation report which contains a copy of Alert Bulletin 91-3 can be found at www.nfpa.org.

Samuel S. Dannaway, P.E., FSFPE, is a registered fire protection engineer and mechanical engineer with bachelor’s and master’s degrees from the University of Maryland Department of Fire Protection Engineering. He is past president and a fellow of the Society of Fire Protection Engineers. He is president of S. S. Dannaway Associates Inc., a 15-person fire protection engineering firm with offices in Honolulu and Guam. He can be reached via email at SDannaway @ssdafire.com.

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