Safety Speed WP 4: Formulation of Flooding RiskCost Models

1
Safety _at_ SpeedWP 4 Formulation of Flooding
Risk/Cost Models
The Ship Stability Research CentreDepartment of
Naval Architecture and Marine EngineeringUniversi
ties of Glasgow and Strathclyde
Bureau Veritas HQ 15-17 May 2002, Paris
2
Primary Initiating Events

• Collision
• Grounding
• Structural failure of bow or stern doors
• Mechanical failure of watertight barriers
• Operational safety management systems failure /
  human error

3
Modelling Water Ingress
First-Principles Tools for RBD Damage
Survivability
4
Static Equivalent Method - SEM

• Generalized formulas for Hs, the critical
  survivable sea state
• h f based on static properties
• Hs function of h f based on statistical
  correlation.

5
Example of RBD for Damage Survivability
Subdivision Index A

• Factor pi represents the probability that a
  compartment or group of compartments will be
  flooded
• Factor si represents the probability that the
  ship will survive flooding of the said
  compartment or group of compartments

Survival Probability

• Factor sa reflects the probability that the ship
  will survive pure loss of stability, heeling
  moments, cargo shift, angle of heel and
  progressive flooding
• Factor sw reflects the probability that the ship
  will survive large scale flooding on the main
  vehicle deck Sw FHscritical(h)

6
Damage Survivability Uncertainty Modelling

• External/Environmental conditions (operational
  sea state(s))
• Internal ship arrangements, layouts and operating
  conditions
• ? Operating draughts and centres of gravity
• ? Internal layouts below and above the car
  deck
• ? External shape of the hull form

7
Capsize Hs vs. Intact Draught SEM Results
8
Intact Draught Distribution
Source Joint NEW Project
9
Distribution of Capsize Hs - Histogram
10
Distribution of Capsize Hs Cumulative Curve
Probability to Capsize
Target Hs
11
Generic Event Tree for Collisions
Source Joint NEW Project
12
Cost Model for Evaluation of Risk Control Options