TS-128
Assessment of Stability in Damaged Condition for a Ship with a Novel Arrangement of Internal Spaces
Miroslaw K. GERIGK* and Yasushi YOSHIDA**
ABSTBACT
The paper presents some results regarding the risk assessment for a ship with the novel arrangement of internal spaces, at the preliminary stage of design. The objective of the research is to introduce a method for the multi-objective and multi-parametric-variation investigations to achieve the required and optimal levels of a ship safety in damaged condition. The method is a parametric-risk-based one. It uses the elements of knowledge following from the formal safety assessment (FSA) methodology, ship hydromechanics and ship safety. A computational model has been developed and it works as a kind of database. It consists of a few modules: design requirements, constraints and criteria ship and environment definition, hazard identification, hazard and risk assessment, modification of design and decisions on safety.
The results follow from the computer simulation of the risk assessment (assessment of the ship safety in damaged condition) for a container and general cargo vessels with a novel arrangement of internal spaces anticipated at the preliminary stage of design.
The practical remarks regarding the method, computational model and preliminary results are given.
Key Words: safety, design, systems, computer, simulation.
1. INTRODUCTION
The research problem concerns development of a method for the ships safety estimation in critical conditions at the preliminary stage of design. The major application area for the method should be the "design for safety" using the risk assessment approach. The objectives followed from the design for efficiency should be taken into account, too.
The method is integrated as the influence of many factors on the ships safety may be investigated.
The ships safety estimation is connected with the risk assessment regarding the stability, damage stability and survivability.
The risk assessment for survivability may concern as follows:
- estimation of the probability of a ship survival when flooding any group of compartments;
- estimation of the probability of oil out-flow according to the arrangement of internal spaces of a ship;
- estimation of the probability of a ship survival in particular cases (direct method preferred).
The critical conditions have been defined as the ingress of external water into any group of watertight compartments of external water into any group of watertight compartments of a ship associated with the following impacts:
- internal - cargo and/or ballast shift
- external - waves, wind.
The knowledge base for the research is as follows:
- naval architecture;
- ship hydromechanics;
- system approach to safety;
- safety case / formal safety assessment (FSA) approach;
- IMO and SOLAS regulations regarding safety.
2. CURRENT RESEARCH PROJECTS REGARDING THE SHIPS SAFETY ESTIMATION FOR DESIGN
The problems studied according to the "Safety of Passenger/RoRo Vessels" project established by the Nordic countries - MO Document, 1996 [1]:
- damage stability modelling methods;
- watertight integrity;
- collision damage extent;
- dynamic effects in waves.
The results of the project contained three important new elements: minor damage concept probability of survival. major damages.
There is the SAFER-EURORO programme directed by the Ship Stability Research Centre at the Strathclyde University in the United Kingdom - Working Document [8]. This is a multi - disciplinary research programme for developing an integrated approach to designing safe passenger/ro-ro ferries and to implement this approach to actual design examples.
The programme is structured as a cluster of individual projects, each addressing a special area in ship design and operation.
