Transcript A Simplified Model for Fire Escalation Assessment Onboard Ship

Evacuation Simulation of Shipboard
Fire Scenarios
Camille Azzi, Andrew Pennycott, George Mermiris, Dracos Vassalos
Fire and Evacuation Modelling Technical Conference
Baltimore, US
August, 2011
Contents of the Presentation
• Introduction
• IMO Guidelines on Evacuation
• Modelling Approach
• Case Study
• Conclusions
Introduction – Ship Safety
Safety becoming target hard to achieve as ships
are getting more complicated
Prescriptive rules outdated
Alternative arrangements
Proactive approach
Introduction – Shipboard Fire
• Fires are statistically most frequent hazards that
ships face at sea
• Shipboard fires
are dangerous
especially
onboard
passenger ships
with dense
occupancy
Source: DNV
collision
grounding
fire
0
0.002
0.004
0.006
0.008
0.01
Frequency per Ship Year
0.012
0.014
Introduction – Evacuation
• Ease of evacuation is crucial under any
hazardous condition
• Normal drills differ from actual
evacuations in fire and
flooding events
www.shipevacuation.com
• Evacuation
assessments are
better done
through modelling
Introduction – Ship Design
Assigned
Costs
Knowledge
about the ship
Freedom to make changes
Concept Design
Contract
Time
Introduction – Ship Design
Increased
knowledge
Knowledge
about the ship
Decision making shift
Freedom to make changes
Concept Design
Contract
Time
IMO Guidelines on Evacuation
• Demographic distribution of passengers
• Walking speed according to
demographics and route type
Day case
Night case
Response
time follows
lognormal
distribution
Time in seconds
Time in seconds
Modelling Approach
Quantification of Fire Effects
• Fire effects on human life safety
– Toxicity (CO, CO2 and O2)
– Heat (convection and radiation)
– Visibility impairment (walking speed reduction)
• Health status categories at different Fractional
Effective Doses (FED)
FED Range
Category
0 ≤ FED < 0.3
Negligible
0.3 ≤ FED < 0.7
Mild injury
0.7 ≤ FED < 1
Serious injury
1 ≤ FED
Fatality
Evacuees Reaction to Fire Effects
• Initially passengers are assigned response times
• Reaction lag ignored and evacuation triggered
– directly exposed to fire effects
– alerted by other passenger or crew
• Avoid hazardous areas: modified graph
Case Study
Case Study
MVZ 1
MVZ 2
Zone affected by fire conditions
MVZ 3
Case Study
FIRE DOORS
PASSENGER CABINS
STAIRWELLS
FIRE CABIN
Fire Simulations
Evacuation Simulations
Cumulative Evacuation Time
% of Simulation Runs
100
80
No crew assistance
60
Crew alert passengers
in the affected area
40
20
No injuries recorded
0
12
14
16
18
Evacuation Time (min)
Without crew assistance
With crew assistance
20
Injuries and Fatalities
Conclusions
• Difficulties of evacuation at sea: complex
geometry, familiarity and fire effects
• Study case highlights importance of crew
assistance
• Human behavior and decision-making
currently simplified
• Further development required based on
observations from reported accidents
The authors greatly
acknowledge the contribution
of EC through the research
project FIREPROOF
www.fireproof-project.eu
THANK YOU