fire safety implications for power engineers

Fire Safety Implications for Power Engineers

Carl D. Wren, P.E.Chief EngineerAustin Fire Department

Fire Behavior – Fire Dynamics

FIRE Reference 16 a rapid (exponential growth), self sustaining oxidation process accompanied by the evolution of heat and light of varying intensities

Fire Behavior – Fire Dynamics

Mattress Fire, Reference 1

Fire Behavior – Fire DynamicsHuman viability is affected by

multiple products of combustion: Heat (thermal burns, respiratory

damage) Smoke (particulate, vapor, and gaseous)

Effects include toxins and reduced visibility Oxygen deprivation

Products of combustion vary by fuel but always include CO

Fire Behavior – Fire DynamicsFire can be self limiting in common

situations. Controlling Factors Are: Available Fuel Supply (furniture, structure,

other contents) Available Oxidizer – Ventilated Fire or

Unventilated Fire; Chemical Oxidizers

Design, Construction and Occupancy can contribute to these limitations (types and continuity of fuels and oxidizers)

Fire Triangle or Tetrahedron

Heat

Oxygen

Fuel

Heat Transfer Energy tends to move toward equilibrium – a

body or material at a higher energy state will tend to transfer energy to a body (or bodies) at a lower energy state(s)

Heat Energy is transferred from a warm or more energetic body to a cooler or less energetic body by one of three mechanisms conduction, convection, or radiation

Types of Construction and Fire/Collapse

HazardsFire Resistive Construction (I-FR, IA)Concrete and protected steelMay or may not be compartmentedTypical construction for high-rises

Typical HazardsFires are generally content firesNot a severe “collapse” hazard (WTC, not normal

hazards)Spalling of concreteCentral HVAC as a smoke travel path (also floor/ceiling penetrations and voids)Hazards may be most obvious on floor above fire floor

Emergencies Affecting Structures References – See Specific Incidents

High Rise Fires 1911 Triangle Shirtwaist

Company NY, NY 1980 MGM Grand Hotel

Las Vegas, NV 1986 Dupont Plaza

San Juan, Puerto Rico 1988 1st Interstate Bank

Los Angeles, CA 1991 One Meridian Plaza

Philadelphia, PA

Triangle Shirtwaist Company 1911 - NY, NY (Reference 2)

March 25, 191110 Stories146 Deaths (female immigrant workers)62 JumpedNo Structural FailureResulted in Major Labor Law and Workplace Safety Changes

1988 1st Interstate BankLos Angeles, CA (Reference 7)

May 4, 1988Wilshire BV @ Hope Street62 StoriesStarted on 12th FloorGutted 4 floorsNo operable sprinklers1 Civilian death (security guard)Fire spread vertically at least in part due to lack of seals at curtain walls~$50,000,000 loss

1991 One Meridian PlazaPhiladelphia, PA (Reference 8)February 23, 1991

1414 South Penn SquareImproper penetration seals in mechanical rooms38 StoriesStarted on 22 Floor8 Floors Gutted & Structural Damage on 10 Floors3 Firefighter deathsPartial SprinklersEventually demolished~$300,000,000 Loss

MGM Grand HotelLas Vegas, Nevada (References 9, 10, & 13)

•November 1, 1980

•85 Deaths (60oC can sear the lungs)

•Approximately700 Injuries

•~$30,000,000 loss (1980 dollars)

•No structural collapse

Type II Construction andFire/Collapse HazardsNon-Combustible or Limited Combustible Construction (II-H, II-A)

Metal, masonry, or concrete wall construction with metal roof

Some Typical Hazards

Unprotected lightweight steel roof joist & I-Beams

Roofs are typically flat w/ combustible weather covering

Ignition of built-up roofing may be above ceilings & therefore above fire sprinklers

Concentrated roof loading can result from HVAC units, etc.

Steel expands ~2.54 cm (1”) per 3.05 m (10’) at 593oC (1100oF)

Steel loses ~40% of load capacity after ~10min. @ 593oC (1100oF)(some conflicting positions on this data)

Types of Construction and Fire/Collapse Hazards

Ordinary Construction (III)Freestanding masonry or brick walls

* Can be FRTW in FR assembliesSolid wood joist flooring and roofing(this is typically within older buildings)Wood truss assemblies (typical in newer buildings)

Some Typical HazardsCombustible concealed spacesPeaked roof concealed spacesLack of or damaged draft or fire stoppingDecorative parapet wallsFire cut beams


Heavy Timber Construction* Wood frame of large cross section (20.3 cm [8”] minimum dimension for vertical members and 15.2 cm [6”] minimum dimension horizontal members)

* High fuel load is present in the structural members exclusive of contents

* May include masonry walls with collapse hazards similar to ordinary construction

* May survive long periods of fire exposure - but control in advanced stages of fire may be very difficult

* Radiant heat exposures may be extreme


Wood Frame Construction * Structure of light weight wood members (less than heavy timber dimensions) typically consisting of wood 5.08 cm (2”) thick by

various widths* Entire frame is part of fuel package* Small dimensions can be compromised more quickly than heavy timber (5cm x 10 cm [2”x 4”] bearing members)

* Braced Frame (mortised connections), Platform (sectional framing & multi-story), and Balloon Framing (fire & smoke travel paths)

* Failure of wood frame bearing walls may trigger simultaneous collapse of floors and/or roof

Centennial Condominium FireFriday December 13, 1996

$12 million damage.1 square block destroyed.75 homeless.More than 100 firefighters to control.Had not been inspected in years.Not in compliance with codes…

Source Austin Fire Department Incident Records

Centennial CondominiumsAustin, Texas

Centennial Condominium FireFriday December 13, 1996

Cocoanut Grove Nightclub FireBoston, MA (Reference 11)

November 28, 1942492 known deathsContributing Factors – Combustible finishes and furnishing Locked exits Possible overcrowding State of available burn & smoke injury

treatment Firefighting limitations (manual & automatic)

Beverly Hills Supper ClubSouthgate, Kentucky – 1977 (Reference 12)

May 28, 1977165 known deathsContributing factors Combustibility of finish materials (even

after a major fire in 1970) Exit design Overcrowding Lack of automatic detection and

suppression

STATION NIGHTCLUB FIRE(Reference 13)

February 17, 2003100 deaths/250 injuriesPossible contributing factors Pyrotechnics Exiting arrangement/overcrowding Door swing and broken door hardware No sprinklers Foam plastic finish materials

STATION NIGHTCLUB FIRE

Place: West Warwick, RIStructure: 1 story, <4,000 square feetOccupancy: NightclubLegal Occupant Load: Between 300 and 360 (based on exiting capacity)Estimated Actual Occupant Load: ~420No Fire Sprinklers

Fire Consequences

In 2001 Fire Losses (Reference 3): 6,196 deaths (2,451 on 9/11 + 3,745) 21,100 injuries (800 on 9/11 + 20,300) $44,023,000,000 in property loss

$33,440,000,000 related to 9/11$10,582,000,000 independent of 9/11

Fire Consequences

In 2002 Fire Losses (Reference 4): 3,380 deaths 18,425 injuries $10,337,000,000 in property loss


Fire Consequences



EMERGENCY AND STANDBY POWER SYSTEMS

Summary in IBC SECTION 2702

2702.1 Installation. Emergency and standby power systems shall be installed in accordance with the ICC Electrical Code, NFPA 110 and NFPA 111.

Buildings and Occupancies Requiring Standby or Emergency Power

Emergency and standby power generators listed in accordance with UL 2200.

Required InstallationsGroup A occupancies. Smoke control systems. Exit signs. Means of egress illumination. Accessible means of egress elevators. Horizontal sliding doors.

Buildings and Occupancies Requiring Standby or Emergency Power

Semiconductor fabrication facilities. Membrane structures. Hazardous materials. Highly toxic and toxic materials. Organic peroxides. Pyrophoric materials. Covered mall buildings.

Buildings and Occupancies Requiring Standby or Emergency Power High-rise buildings. Underground buildings. Group I-3 occupancies. Airport traffic control towers.. Elevators. Smokeproof enclosures. Maintenance. Emergency and standby

power systems shall be maintained and tested in accordance with the International Fire Code.

Standby Power for Covered Mall Buildings

Covered mall buildings exceeding 50,000 square feet (4645 m2) shall be provided with standby power systems for the operation of the emergency voice/alarm communication system.

Fire & Building Code Standby Power Requirements for High Rise Buildings

A standby power system shall be provided for standby power loads specified in IBC Section 403.10.2.

Special requirements for standby power systems. A generator set inside a building shall be located in a separate room enclosed with 2-hour fire-resistance-rated fire barrier assemblies. System supervision and manual start and transfer features are required at the fire command center.

Fire & Building Code Standby Power Requirements for High Rise Buildings

The following are classified as standby power loads:1. Power and lighting for the fire command center;

2. Electrically powered fire pumps;

3. Ventilation and automatic fire detection equipment for smokeproof enclosures.

Standby power shall be provided for high rise elevators in accordance with IBC Section 3003.

Fire & Building Code Emergency Power Requirements for High Rise Buildings

An emergency power system complying with Section 2702 shall be provided for the following emergency power loads.The following are classified as emergency power loads:1. Exit signs and means of egress illumination required

by IBC Chapter 10;2. Elevator car lighting;3. Emergency voice/alarm communications systems;4. Automatic fire detection systems; and5. Fire alarm systems.

Standby Power for Atrium Buildings

404.6 Standby power. Equipment required to provide smoke control shall be connected to a standby power system in accordance with IBC Section 909.11.

Fire & Building Code Power Supply Requirements for Underground Buildings

A standby power system complying with Section 2702 shall be provided for the following standby power loads.The following loads are classified as standby power loads.1. Smoke control system.2. Ventilation and automatic fire detection equipment for smokeproof

enclosures.3. Fire pumps.

Standby power shall be provided for elevators in accordancewith Section 3003.The standby power system shall pick up its connected loads within 60 seconds of failure of the normal power supply.

Fire & Building Code Power Supply Requirements for Underground Buildings

Emergency power. An emergency power system complying with Section 2702 shall be provided for the following emergency power loads.

Emergency power loads. 1. Emergency voice/alarm communications systems.

2. Fire alarm systems.

3. Automatic fire detection systems.

4. Elevator car lighting.

5. Means of egress and exit sign illumination as required

by Chapter 10.

Fire & Building Code Power Supply Requirements for Airport Traffic Control Towers

A standby power system that conforms to Section 2702 shall be provided in airport traffic control towers more than 65 feet (19 812 mm) in height. Power shall be provided to the following equipment:1. Pressurization equipment, mechanical

equipment and lighting.2. Elevator operating equipment.3. Fire alarm and smoke detection systems.

Fire & Building Code Power Supply Requirements for Haz Mat Storage414.5.4 Standby or emergency power. Where mechanical ventilation, treatment systems, temperature control, alarm, detection or other electrically operated systems are required, such systems shall be provided with an emergency or standby power system in accordance with the Electrical Code.Exceptions:1. Storage areas for Class I and II oxidizers.2. Storage areas for Class III, IV and V organic peroxides.3. Storage, use and handling areas for highly toxic or toxic materials as

provided for in the International Fire Code.4. Standby power for mechanical ventilation, treatment systems and

temperature control systems shall not be required where an approved fail-safe engineered system is installed.

Fire & Building Code Power Supply Requirements for Semiconductor Fabs

An emergency power system shall be provided in semiconductor fabrication facilities where required in IBC Section 415.9.10.1.

The emergency power system shall be designed to supply power automatically to required electrical systems when the normal electrical supply system is interrupted.


Emergency power shall be provided for electrically operated equipment and connected control circuits for the following systems in semiconductor fabrication facilities:1. HPM exhaust ventilation systems.2. HPM gas cabinet ventilation systems.3. HPM exhausted enclosure ventilation systems.4. HPM gas room ventilation systems.5. HPM gas detection systems.6. Emergency alarm systems.7. Fire alarm systems.8. Automatic sprinkler system monitoring and alarm systems.9. Electrically operated systems when required elsewhere in

order to use, store or handle HPM.


415.9.10.2 Exhaust ventilation systems. Exhaust ventilation systems are allowed to be designed to operate at not less than one-half the normal fan speed on the emergency power system where it is demonstrated that the level of exhaust will maintain a safe atmosphere.

Power Supply Requirements for Smoke Control Systems

Required smoke control systems shall be supplied with two sources of power. Primary power shall be the normal building power systems. Secondary power shall be from an approved standby source complying with the Electrical Code. The standby power source and its transfer switches shall be in a separate room from the normal power transformers and switch gear and shall be enclosed in a room constructed of not less than 1-hour fire-resistance-rated fire barriers ventilated directly to and from the exterior. Power distribution from the two sources shall be by independent routes. Transfer to full standby power shall be automatic and within 60 seconds of failure of the primary power. The systems shall comply with the ICC Electrical Code.Elements of the smoke management system relying on controls such as computer or microprocessor memories shall be supplied with uninterruptable power sources adequate to span a 15-minute primary power interruption.

Fire & Building Code Power Supply Requirements Exit IlluminationThe power supply for means of egress illumination shall normally be provided by the premise’s electrical supply.

In the event of power supply failure, an emergency electrical system shall automatically power the illumination for the following types of areas:

1. Exit access corridors, passageways and aisles when two or more means of egress are required.

2. Exit access corridors and exit stairways located in buildings required to have two or more exits.

3. Exterior egress components at other than the level of exit discharge until exit discharge is accomplished for buildings required to have two or more exits.

4. Interior exit discharge elements, as permitted in Section IBC 1023.1, in buildings required to have two or more exits.

5. The portion of the exterior exit discharge immediately adjacent to exit discharge doorways in buildings required to have two or more exits.

Fire & Building Code Power Supply Requirements Exit Illumination

The emergency power system shall provide power for a duration of not less than 90 minutes and shall consist of storage batteries, unit equipment or an on-site generator. The installation of the emergency power system shall be in accordance with IBC Section 2702.

Fire & Building Code Power Supply Requirements Exit Signs

Exit signs shall be illuminated at all times. Continued illumination for a duration of not less than 90 minutes is required when there is a primary power loss. The sign illumination means shall be connected to an emergency power system provided from storage batteries, unit equipment or an on-site generator. Exception: When approved exit sign illumination means provide continuous illumination independent of external power sources for a duration of not less than 90 minutes, in case of primary power loss, an emergency electrical system is not required.

Fueling Issues For Outdoor Generator SetsGeneral Requirements for Outdoor Diesel

Generator InstallationsSecondary containment required. If double walled

tank is used, interstitial leak detection is required in tank annular space.

Normal vent routed outside weather enclosures at least 12 feet above grade

AFD Aboveground Hazardous Materials Permit is required if greater than 275 gallons.

Fueling Issues For Outdoor Generator SetsA public hearing is required if the aggregate

volume is greater than 12,000 gallons.NFPA 704 placard and DIESEL signs required

on tank.Vehicle impact protection per IFC.Must be within 150 feet of fire department

access road and must have at least one fire hydrant within 500 feet.

Outdoor Diesel Tank Requirements

Tank is 275 gallons or less. 5 ft from property lines that can be built upon, public ways and

buildings. UL 142 listed tank

Tank is 276-500 gallons. 10 ft from property lines that can be built upon and public ways

and 5 ft from buildings. UL 142 listed tank

Tank is 501- 660 gallons. 10 ft from property lines that can be built upon and public ways

and 5 ft from buildings. UL 142 listed tank. Overfill prevention valve required at fill connection.

Outdoor Diesel Tank Requirements

Tank is 661-2,000 gallon Risk assessment required. 150 foot setback required from certain

occupancies (assemblies, daycares, hotels, hospitals, residential, nursing homes).

7 ½ feet from property lines that can be built upon and public ways. 5 feet from buildings.

UL 2085 Protected Aboveground Tank Additional requirements see IFC Section 3404.2.9.6

Tank is 2,001-12,000 gallon Risk Assessment Required. 175 foot setback required from certain

occupancies (same as above). 7.5 feet from property lines than can be built upon and public ways.

5 ft feet from buildings. UL 2085 Protected Aboveground Tank Additional requirements see IFC Section 3404.2.9.6

Heat Load Comparison

Time Temperature Curves

0

500

1000

1500

2000

2500

1 5 9 13

17

21

25

29

33

37

41

45

49

53

57

61

Time (min)

Tem

pera

ture

(F

)

Standard Curve Temperature (°F) UL 1709 Curve Temperature (°F)

Fueling Issues For Indoor Generator Sets

General Requirements for Indoor Installations

Tank must be UL 142 listed.

An AFD Aboveground Hazardous Materials Permit is required if the volume is greater than 120 gallons.

The normal and emergency vents for the primary tank must extend outside of the building at least 12 feet above grade and 5 feet from building openings.

Fueling Issues For Indoor Generator Sets

The fill connection for the tank must extend outside the building at least 5 feet from building openings or lot lines of property that can be built upon.A public hearing is required if the aggregate volume is greater than 12,000 gallons.NFPA 704 placards and Diesel signs required on the tank.NFPA 704 placard required on the door to generator room.

Indoor Fuel Tank Requirements

Tank is less than 120 gallons. Volume is less than the exempt amount established in

the IFC. Tank may be located in a nonsprinklered building.

Tank is 121-240 gallons. Volume is less than the exempt amount for a sprinkler

protected building. Tank may be located in a sprinkler protected building that is not classified as a Group H occupancy.

Installations on the roof of a sprinklered building or top level of a sprinkler protected parking garage are limited to 120 gallons.

Indoor Fuel Tank Requirements

Tank is 241-500 gallons. Volume is above the exempt amounts. A Group H-2 or H-3

occupancy is required. A Group H-2 occupancy is required if the system is pressurized at more than 15 psig.

Room must be constructed in accordance with the IFC and IBC and provided with secondary containment, mechanical ventilation, fire barrier walls, automatic fire sprinkler system, emergency alarms, etc.

Tank is 501-12,000 gallons. Volume is above the exempt amounts. A Group H-2 or H-3

occupancy is required. A Group H-2 occupancy is required if the system is pressurized at more than 15 psig.

Room must be constructed in accordance with the IFC and IBC and provided with secondary containment, mechanical ventilation, fire barrier walls, automatic fire sprinkler system, emergency alarms, etc.

Overfill prevention is required in accordance with IFC Section 3404.2.9.4.

Impacting Fire & Life Safety

Consider the abilities and resources of firefighting and rescue personnel near your projects and be realistic.

Impacting Fire & Life Safety

Use the rule of thumb of the emergency services – risk versus benefit – risk (invest) a lot for a life (maybe even another life) – risk little for little gain

but again be realisticwe cannot and will noteliminate all risk

Codes & Standards

Know the applicable codes and understand the code and standards development processes: International Code Council

(a consortium of ICBO, BOCA, and SBCCI) Meant to create a single consistent series

of codes for the USA (world?) National Fire Protection Association (NFPA)

Codes and Standards - ICC

International Codes Series - e.g. International Building Code (IBC) International Fire Code (IFC)

Performance Based Codes

NFPA 101, Chapter 52003 ICC Performance for Buildings and Facilities NFPA 5000, Chapter 5

Standards - NFPA

NFPA 13, Fire Sprinkler StandardNFPA 72, Fire Alarm StandardNFPA 14, Standpipes (Hose Systems)NFPA 70, National Electrical CodeNFPA 110, Emergency & Standby Power SystemsNFPA 111, Stored Electrical Energy Emergency and Standby Power Systems

Systems and Specific DesignCodes and Standards

NFPA 70, National Electrical Code (NEC)


NFPA 72, Fire Detection and Alarm


ANSI A-17.1 & A-17.3 Elevators


NFPA 101, Chapter 52003 ICC Performance for Buildings and Facilities NFPA 5000, Chapter 5


Many New Technological Tools Such as Computer Fire Models Are Now Available To Enhance This Option For Many Larger, More Complex Projects.Reference 14

References

1. National Institute of Standards and Technology (NIST), Building and Fire Research Laboratory, “Fire on the Web, Fire Scenarios”, http://fire.nist.gov/fire/fires/fires.html

2. “The Triangle Shirtwaist Fire”, by Paul Rosa, History Buff.com, http://www.historybuff.com/library/refshirtwaist.html

3. Fire in the United States 1992–2001, Thirteenth Edition, October, 2004, U.S. Fire Administration, Federal Emergency Management Agency, Emmitsburg, Maryland 21727

4. FIRE LOSS IN THE UNITED STATES DURING 2002, by Michael J. Karter, Jr., National Fire Protection Association, Fire Analysis & Research Division, Quincy, MA, September 2003

5. FIRE LOSS IN THE UNITED STATES DURING 2003, by Michael J. Karter Jr., National Fire Protection Association, Fire Analysis & Research Division, Quincy, MA, October 2004

6. “Investigation Report on the DuPont Plaza Hotel Fire”, National Fire Protection Association, Quincy, MA, 1987

7. “Investigation Report on the First Interstate Bank Building Fire”, National Fire Protection Association, Quincy, MA, 1988

8. “Fire Investigation Report on the One Meridian Plaza Fire”, National Fire Protection Association, Quincy, MA, 1991

References (Continued)

9. “Preliminary Investigation Report on the MGM Grand Hotel Fire”, National Fire Protection Association, Quincy, MA, 1981

10. “Official Findings on the MGM Grand Hotel Fire”, Clark County Fire Department, Las Vegas, NV, 1981 http://www.co.clark.nv.us/fire/mgm_doc.htm

11. “The Cocoanut Grove Nightclub Fire” by Robert S. Moulton, National Fire Protection Association, Quincy, MA, 1962

12. “Fire Investigations on the Beverly Hills Supper Club Fire”, National Fire Protection Association, 1978 and 1979

13. Oral Presentations by Frederick Mowrer, PhD, Jeff Shapiro, et al

14. National Institute of Standards and Technology (NIST), Building and Fire Research Laboratory, “NIST Fire Dynamics Simulator (FDS) and Smokeview”, http://fire.nist.gov/fds/

References (Continued)

15. Fire Research Division Building and Fire Research Laboratory National Institute of Standards and Technology, NIST NCSTAR 2: Vol. I, Report of the Technical Investigation of The Station Nightclub Fire, by William Grosshandler, Nelson Bryner, Daniel Madrzykowski, and Kenneth Kuntz, June 2005

16. A combination of various definitions but core is from page 1-4 of “Fire Dynamics Tools (FDTs) Quantitative Fire Hazard Analysis Methods for the U.S. Nuclear Regulatory Commission Fire Protection Inspection Program”, Draft Report for Comment, U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, Washington, DC 20555-0001

17. “The U.S. Fire Problem”, National fire Protection Association, Quincy, MA,http://www.nfpa.org/itemDetail.asp?categoryID=953&itemID=23072&URL=Research%20&%20Reports/Fire%20statistics/The%20U.S.%20fire%20problem

18. Code Requirements Are Taken From the 2003 Editions of the international Fire Code or the 2003 Edition of the international Building Code, International Code Council, 2003

References (Continued)A good contact for additional information and data concerning fire losses and statistics is the NFPA One Stop Data Shop:

Nancy SchwartzNational Fire Protection AssociationOne-Stop Data Shop1 Batterymarch ParkQuincy, MA 02169-7471Phone: +1-617-984-7450Fax: +1-617-984-7478e-mail: [email protected]

fire safety implications for power engineers

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