Transcript Fires in Vehicular Tunnels

12th North American/US Mine Ventilation Symposium
Fires in Vehicular Tunnels
An Overview
Ian J. Duckworth, Ph.D., P.E.
Senior Project Manager, Freeport McMoRan Copper & Gold
(formerly Senior Program Director, Earth Tech)
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Background


Thousands of road and rail tunnels are in service worldwide

Some meet modern safety standards

Majority do not
Major fire is one of the primary risks recognized by operators

Many modern tunnels safer, per kilometer, than above ground

Public perception and reaction to major tunnel fire

General public neither trained nor equipped to fight fires or evacuate
under smoke conditions

Loss of life unacceptable
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Transportation Tunnels


Road Tunnels

Particular safety focus during last decade

Tunnels in service that do not meet modern standards

Large road tunnels may have +50 accidents/yr and +3 fires/yr majority minor
Subways

Complex networks of tunnels and stations


New York: +1,000km track, 468 stations, 4.8 million ppd
London: +400km line, 274 stations, 2.7 million ppd

Original design for control of environment not fire / Passive

Heavily urbanized areas / Deep mined stations

Large transit systems may have +30 fires/yr – majority minor
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Road Tunnel Fires
Date
Name
Country
Mar 2007
Burnley Tunnel
Australia
Sep 2006
Viamala A-13
Jun 2005
Length
Cause of Fire
Fire Duration
Fatalities/Injuries
3,400m
Truck / car collision
1 hr
3 dead / 2 injuries
Switzerland
742m
Car & bus collision
4 hrs
6 dead / 6 injured
Fréjus T2
France-Italy
12,895m
Truck fire – mechanical
6 hrs
2 dead / 21 injured
Oct 2001
St. Gotthard A-2
Switzerland
16,918m
2 truck collision
Aug 2001
Gleinalm A-9
Austria
8,320m
2 car collision
May 1999
Tauern A-10
Austria
6,401m
2 trucks/4 cars collide
16 hrs
12 dead/49 injured
Mar 1999
Mont Blanc
France-Italy
Truck fire – mech
56 hrs
39 dead
Mar 1996
Is. De. Femmine
Italy
Apr 1995
Pfänder
1994
11,600m
48 hrs
-
11 dead
5 dead / 4 injured
148m
Tanker & bus collision
-
Austria
6,719m
Car/truck/van collision
1 hr
3 dead / 4 injured
Huguenot
South Africa
3,914m
Bus electrical
1 hr
1 dead / 28 injured
1993
Serra Ripoli
Italy
442m
Truck & car collision
2 hrs
4 dead / 4 injured
1987
Gumefens
Switzerland
343m
Truck & van collision
2 hr
1986
L'Arme
France
1983
Pecorila Galleria
Italy
1982
Salang
Afghanistan
1982
Caldecott
United States
1980
Kajiwara
Japan
740m
1979
Nihonzaka
Japan
2045m
4 Truck/2 car collision
6.5 days
7 dead / 2 injured
1978
Velsen
Netherlands
770m
2 trucks/4 car collision
1 hr
5 dead / 5 injured
1,105m
5 dead / 20 injured
2 dead
Truck mechanical
-
3 dead / 5 injured
Truck & car collision
-
9 dead / 22 injured
2,700m
Military collision
-
>150 dead
1,028m
Tanker/bus/car collision
662m
3 hrs
Truck collision
-
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7 dead / 2 injured
1 dead
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1999 Mont Blanc Road Tunnel Fire


Major trans-Alpine road tunnel
 11.6 km long, 8.6 m wide, 4.35 m high
 consists of single cross section with a two-lane dualdirection roadway
 Managed by French and Italian public companies
1999 fire resulted in 39 people losing their life
 Initiated by refrigerated truck carrying 9t flour, 12t
margarine & 550 l diesel
 Fire burned for 56 hours, +1,000 °C, and spread to 40
vehicles
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Rail Tunnel Fires
Date
Name
Country
Cause of Fire
Fatalities/Injuries
Feb 2003
Taegu Subway
Korea
Arson. 2 cars engulfed.
192 dead / 148 injured
Nov 2000
Kaprun
Austria
Cable car fire from heater system.
Steeply inclined tunnel.
155 dead
May 1999
Salerno
Italy
Arson suspected.
Tunnel may not have been a factor.
4 dead / 9 injured
Oct 1995
Baku Metro
Azerbaijan
Electrical fault on train.
289 dead / 265 injured
1987
Kings Cross
England
Escalator fire
31 dead
1984
San Benedetto
Italy
Bomb detonated in 18.5 km tunnel.
2 cars destroyed. Small fire.
17 dead / 120 injured
1981
Moscow
Russia
Electrical fault / 2 cars on fire
7 dead
1980
LUL
London, England
Trash fire in cross-passage
1 dead
1979
BART
San Francisco, US
Electrical short-circuit
1 dead / 58 injured
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2003 Taegu Subway Fire

Occurred February 18, 2003
Initiated by an arsonist with gasoline
 Fire destroyed two trains and caused
many additional casualties at
Jungangno Station
 Duration of the fire ~ 3 hrs
 192 fatalities


Such fires have led to changes to the
components of transit vehicles
More fire hardened
 Smoke is less toxic

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What are Conditions Really Like?
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Typical Transportation Tunnel Safety Systems
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Fire & smoke detection systems


Ventilation systems
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Walkways, stairs, dedicated tunnel/plenum/adit, refuge bays, cross
passageways
Fire suppression & rescue


Monitoring, tracking, CCTV, radio, phones
Escape and refuge facilities


Natural, vehicle-induced, mechanical
Traffic operation & information provision
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
Manual, opacimeters, temperature (linear, spot, array), air sampling,
infra-red, UV, image recognition
Passive resistance, standpipe, sprinklers, hydrants, deluge, mist,
screens, etc.
Other – power, lighting, tunnel management, etc.
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Some Design Considerations
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Legislation & Standards

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NFPA 130 & 502
Performance vs. prescriptive design

Strict interpretation of design criteria and standards vs. application of
engineered approach to demonstrate systems are safe

Practical yet sufficient

Maintainable
“The major difference between a thing that might go wrong and a thing
that cannot possibly go wrong is that when a thing that cannot possibly
go wrong goes wrong, it usually turns out to be impossible to get at and
repair.” Douglas Adams: Mostly Harmless
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More Design Considerations


Challenge of retrofit

Innovative solutions often required

Risk of delay – Acceptable?

Compromise – Acceptable?
Keep it simple – if possible
“Engineers like to solve problems. If there are no problems handily
available, they will create their own problems.” Scott Adams

Source of funding – Federal, state, private, combination
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Common Concepts
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Tenability
Visibility (30m for lit sign)
 Heat (temperature and duration)
 Toxicity (combination vs. single gas)
 CFD coupled with evacuation modeling


Fire Heat Release Rate

Rate of fire development, number of
vehicles, flammable liquid spills, etc.
Type of Vehicle
Passenger Car
Multiple Passenger Cars (2-4)
Light Rail Vehicle
Large Passenger Rail Car
Bus
Heavy Goods Truck
Diesel Locomotive
Gasoline Tanker
Peak Fire Heat
Release Rate (MW)
5-10
10-20
9-17
20-30
20-30
70-200
100+
200-300
Urban Vent Shaft Bangkok
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Simulation Software

One Dimensional
Integrated modeling of aerodynamic,
thermodynamic and fire scenarios
 Transient & dynamic requirement


Computation Fluid Dynamics
Prediction of hot smoke and gases from first
principals
 Requirement on most subsurface transit
projects


Evacuation Modeling
Three dimensional modeling of people
 Behavioral aspects
 Coupling with CFD

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Conclusions
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Fires will continue to occur in transportation tunnels


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Responsibility of operators to ensure safety systems and
procedures are adequate to cope with major fires
Design of fire-life safety systems for public subsurface facilities
is a complex process

Standards – Compliance requirements
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Constructability considerations

Retrofit for existing tunnels presents unique challenges
Consider the future

Tunnels, once built, are around for a long time

Facility upgrades will continue to be required
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Support Material
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and doors and walls are discernible at 10 meters (33 feet).
NFPA 130 Annex B2.2 proposes these criteria to be applied at 2.5 m (8.2 ft) height above the walkway
for visibility, to allow a margin of simulation error above head height.
Visibility & Smoke Concentration
A combined visibility calculation methodology will be used.
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The extinction coefficient (K [m ]) for a lit sign at a distance S (m) is defined as:
K
8 -1
(m )
S
Where 8 is a constant (ref. Klote & Milke). The maximum allowed extinction coefficient, relating to a
minimum 30 m distance is therefore:
K
8
 0.267 m-1
30 m
The allowable smoke concentration (Csmoke) is calculated from:
Csmoke 
K
8
(1)

7.6 7.6 S
The smoke obscuration levels, or visibility is derived from the equation:
Csmoke 
Ys Cprod
(1  AF)
(2)
AF represents the combustion ratio of air mass to fuel mass, which is assumed to be 14. Ys represents
the smoke yield (0.129 gsmoke/gfuel) as a mass ratio. Therefore, from substituting (2) into (1), the visibility S
(m) is evaluated from CFD by:
S
8 1  AF
122.4

7.6 YsCprod
Cprod
CFD results will report both
of visibility (distance)
and smokeSymposium
concentration.
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CFD Notes
CFD analysis conducted by creating three-dimensional mesh models. The
mesh consists of thousands of small cells or elements. The software solves
the partial differential equations for the conservation of mass, momentum,
species, turbulence scalars (k and epsilon), and energy in each cell.
The simulation results provide air velocities, temperatures, pressures, and
concentration of products of combustion. A time sequence of these results
portrays the spread of smoke, the rise of temperatures, and the airflow
patterns as they relate to evacuation routes.
Time-squared fires are described in NFPA 92B as having slow, medium, fast
and ultra-fast growth rates. Typical medium for transit and fast for road
vehicles.
Smoke production often based on 75% efficiency. Fire growth modeled by
expanding the volume to which heat is added in steps.
Transient and steady state simulation used.
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