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Weapons of Mass Destruction Threat Assessments and its Impact on Full High-Rise Building Evacuations
Presented at the Urban Hazards II Forum - "Homeland Security after 9/11" -
John Jay College, NYC,
January 23-24, 2003
Presented by Jack J. Murphy, Vice-Chairman /
Fire Safety Directors Association of Greater New
Over the years, we have learned to navigate a
high-rise building fire evacuation by vacating to several floors
below the incident and staging there for further evacuation, if
necessary. The high-rise building means of egress have been
designed around this half-hearted "defend-in-place" practice. I
advocate this because not all high-rise structures are fully
sprinkled nor segregated into floor fire compartments. And the
fire loads on many floors far exceed the capacity of fire
department hose streams. If not for the beliefs of
"defend-in-place", the engineers and architects would have
designed the egress means accordingly and the objective would
more than likely resemble our Madison Square Garden stair and
ramp egress widths and the street level exit discharge
components. Even the foremost of all egress practices, the
National Fire Protection Association, Life Safety Code 101 has
never thought it necessary to deploy a full high-rise building.
Collectively we have all failed to meet the riggers of a full
high-rise building evacuation.
While we still have not fully conquered all the
high-rise fire safety requirements, we are as a group thrown
together with today's Weapons of Mass Destruction [WMD] crisis to
augment rapid deployment procedures for evacuating all occupants
with a limited capability of the high-rise building means of
So how do we safely and pragmatically go about
accomplishing this feat?
For today, let's just discuss some necessary
threat assessments for an internal chemical incident and how it
may affect a full building evacuation:
I. A Reconnaissance of Building Systems is Essential for;
Some key systems are HVAC, Elevators and Communications
- Where are the air in-takes and is there a vulnerability here?
- How many HVAC zones and what areas do they cover?
- If a contaminant is present, can the smoke management system and/or building management system be used to purge the agent? After normal working hours is the building management system remotely controlled off site?
Some building natural air supply advantage points;
- If present, do building setbacks have the capability to temporally stage occupants for fresh air?
- Are windows immediately operable and if not are window keys readily available?
- What if the building is totally sealed?
- What floors do the elevator banks serve?
- Are the various elevator banks present for low-rise, mid-rise and high-rise levels?
- Is a sky lobby present and at what floor levels?
- Do blind shafts exist and what floors do they by-pass?
- Do any of the elevator banks cross over into another HVAC zone?
Communications Capability - Fire Alarm System [FAS]
The high-rise building fire alarm voice communications system is
the most critical equipment for an effective evacuation, yet it
is very vulnerable in many present high-rise structures because
the location of the Fire Command Center [FCC] opens onto the
lobby/atrium area. The potential loss of the FAS voice
communications system during a lobby chemical attack could
render the communications system inaccessible, thus negating
voice communications onto all floors.
- Is there a redundant and remote emergency voice communications system?
- Do the occupants have confidence in the voice that they hear?
- Are the announcements clear and the directions understandable to the floor occupants?
- Do we use for Fire -"Code Red" that signifies a partial evacuation?
- Do we use for Emergencies other than Fire - "Code Black" signifying a full building evacuation, like a chemical incident?
- For WMD threats do we provide specific evacuation information and direct the occupants to the least threatened area of the building?
- When the lobby is not affected, have we assembled at the Fire Command Center a "Chemical Threat Management Team" that consists of the building Fire Safety Director, a Security Supervisor and the HVAC engineer, to assist in the mitigation?
II. Evacuation Concerns for a Chemical Incident:
- What types of stair towers are present to mitigate an evacuation?
- Pressurization with a fan capability
- A fire tower with an enclosed vestibule off each floor that is open to the atmosphere prior to entering into the stair tower itself.
- Or just an enclosed stair with no air movement.
- What stairs discharge directly onto the street?
- Are there any access stairs between floors?
- What are the re-entry floor levels? And how do we release the secured stair tower doors, if an automatic fire alarm device does not release the doors?
Use of elevators for rapid evacuation, especially for disabled
people, may depend on the location of the chemical release. The
potential effect of elevator movement may cause a drawing of the
chemical agent up the elevator shaft.
III. Occupant training for WMD;
- Evacuation phases;
- Training for floor evacuation teams [FET]
- Full building evacuation drill for FET's
- Floor evacuation drill for all occupants
- Full building evacuation
- "Buddy System" for people with a disability
- Exterior points of assembly
IV. High-Rise Vulnerability Enhancements;
- Increase stair widths to a minimum of 55
inches between the handrails. The new design of # 7 WTC has
incorporated a minimum width of 66 inches. While it is
difficult to retrofit stair widths in existing buildings, it
does not preclude the fact that we can enhance a rapid
evacuation by making a Phase IV elevator bank that is water
and smoke proof.
- For easier stair identification, emergency lighting, photo-luminous signage and a sound alert system should all be incorporated.
- Increase exit discharge at the grade level, particularly if only 1 of the 2 stair towers are available during an emergency incident.
- Enclose the lobby Fire Command Center with a 'bunker type' shielded protection. Relocate it to the street side of the building and provide a fortified exterior access door for the fire department.
- Provide a redundant type emergency communications system.
- Assign a dedicated Fire Safety Director whose sole function is life safety for the building occupants. We have more people in many high-rise buildings than communities across this country, yet we entrust numerous high-rise buildings to a person who has no experience with emergency incidents and then we ask them to make split-second life safety decisions for a multitude of potential evacuation strategies.
To apply pragmatic life safety means to current
Weapons of Mass Destruction threat issues, senior management
whether corporate or real estate management, now more than ever,
must coordinate an inclusion of both life safety and security.
Together we can collectively raise the bar on ensuring the
building occupants that a due-diligence is being preformed prior
to the arrival of any First Responder.
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(Presented at the Urban Hazards II Forum - "Homeland Security after 9/11" - John Jay College, NYC, January 23-24, 2003) © Copyright 2003 Jack Murphy.