The "Project 2" of the programme called the "Design for Survivability (DESURV)" consists of seven tasks. A few of them have been solved, already.
In Poland there has been a set of research projects concerning the ships safety problems. A few of them have been done at the Ship Design and Research Centre in Gdansk. The background of the projects may be found in documents by Pawlowski [6] and Pawlowski and Laskowski [7].
There is a research project No. 9 Tl2C 026 16 founded by the Scientific Research Council KBN which concerns a new method/model for the ships safety estimation in critical conditions. This project is under development at the Chair of Ship Hydromechanics. Faculty of Ocean Engineering and Ship Technology, TUG and it will terminate by the end of 2000. The project has been presented by Gerigk [2] and Gerigk [5].
The tasks associated with the project are as follows:
- damage stability modelling methods;
- large scale flooding;
- dynamic effects due to internal (ballast and/or cargo shift) and external (waves, wind) impacts;
- development of survival criteria for the ships in damaged condition;
- series of investigations including the safety assessment and example preliminary designs.
The main objectives of the research are as follows:
- development of a method for the ships safety estimation when surviving;
- development of the theoretical and computational models for calculation the hydromechanic characteristics of a ship when surviving;
- development of the models (theoretical and computational) for estimating the risk when surviving;
- series of investigations regarding the ships safety when surviving.
The other objectives are as follows:
- development of both the theory of ships and ship hydromechanics;
- supporting the education;
- developing the tools for the preliminary design;
- publications.
Generally, the research is connected with developing the method and model for the ships safety estimation when surviving.
3. MODERN APPROACH TO SHIPS SAFETY
The factors affecting the safety may follow from different sources;
- design;
- operation;
- management.
There are a few levels of factors affecting the safety:
A. First level:
- human factor;
- control systems / technical means;
- Iegislative actions;
B. Second level:
- ship including hull, propeller and rudder particulars;
- cargo including arrangement of internal spaces, cargo and ballast distribution and loading condition;
- environment including wind, waves and current;
- operational connected mainly with the integrated ship management system if available;
- human including both the psychological and physical predispositions, character, morale, integrity, knowledge, experience and training degree;
C. Third level:
- interrelated parameters and characteristics following from the safety domains: stability, damage stability, survivability.
The major source of information on hazards and risks involved in shipping are both the statistics and investigations into serious casualties, documented by Gerigk [4]. Studying these data it becomes clear that the safety of life at sea and the pollution of the environment are a function of the ship's design, operation and management. Therefore, an integrated rational framework is necessary to work out which should apply the approach based on risk acceptance criteria.
Modern approach to ships safety is connected with combining: System Approach and Formal Safety Assessment (FSA).
Formal Safety Assessment (major elements):
- hazard identification;
- risk assessment;
- risk reduction.
4. A METHOD FOR THE SHIPS SAFETY ESTIMATION FOR DESIGN
A method for the ships safety estimation when surviving has been worked out and it is associated with solving a few problems regarding the naval architecture, ship hydromechanics and ships safety and it is novel to some extent.
The method consists of two sub-methods:
- parametric method - when stability and damage stability characteristics are calculated;
- semi-probabilistic or probabilistic-based method - for the survivability and risk assessment related problems.
From the theoretical point of view the method uses:
- global approach;
- technical approach.
From the practical point of view, the method exists in the form of the dynamical database.
The global approach has enabled to prepare the method framework as follows:
- method philosophy development including reviewing literature, estimating safety of existing vessels, reviewing regulations, etc.;
- ship and environment definition;
- hazard and scenario identification;
- hazard and risk assessment;
- hazard resolving and risk reduction;
- decisions made on ship safety (selection of optimal design, operational and mitigation measures).
The technical approach has been connected with developing the following:
- logical structure of design system;
- logical structure of computational model;
- both analytical and numerical methods;
- application methods.
5. COMPUTATIONAL MODEL FOR THE SHIPS SAFETY ESTIMATION FOR DESIGN
The structures of the design system and computational model combine as follows:
- global approach;
- technical approach.
The most important features of the system/computational model are as follows:
- system/model is open;
- system/model structure is hybrid-modular;
- system/model has a common library of analytical and numerical methods;
- system/model has a common library of application methods (direct geometry-based methods are preferable);
