Safety of cruise ships demands persistent research
12.03.2012
The safety of cruise vessels usually becomes a public issue only in the aftermath of catastrophes. The more severe the accident the more acutely arises the need for better ships and better science. The research on ship safety does not however proceed in clear-cut breakthroughs. Safety and stamina of ships in accidents is a sum of numerous uncertainties, and to control them takes wide-ranging and cross-disciplinary research.
The safety of cruise vessels usually becomes a public issue only in the aftermath of catastrophes. The more severe the accident the more acutely arises the need for better ships and better science. The research on ship safety does not however proceed in clear-cut breakthroughs. Safety and stamina of ships in accidents is a sum of numerous uncertainties, and to control them takes wide-ranging and cross-disciplinary research.
The recently finished project FLOODSTAND studied thoroughly the safety of cruise ships and freight transport vessels in flooding scenarios. The three-year project covered topics from ship design, measuring and modelling the flooding caused by damages, and predicting the capsizing of ships, to managing crises situations and rescue operations.
The Aalto University Department of Applied Mechanics coordinated the vast project of 17 international partners comprising universities, research institutes, shipyards, classification agencies and companies from ten European countries.
From hindsight knowledge to risk prediction
One the most critical worries for a ship facing an accident is water flooding in from the damages in the haul. If the water spreads unevenly through the ship’s compartments, the ship will start to capsize. In the worst-case scenario the capsizing will lead to the ship collapsing and sinking.
In FLOODSTAND the effect of flooding on ships was studied in accord with the methods of measuring and controlling the flooding. The risk and the process of capsizing and collapsing was both numerically and analytically modelled and simulated with statistical probabilities.
– There was a lack of knowledge on the progress of flooding and capsizing and on structural failures on board, so we did a lot of experiments in the project, says coordinator Risto Jalonen from the Marine Technology unit of the Department of Applied Mechanics in Aalto University.
– The aftermath of accidents is not a good starting point for research. In FLOODSTAND we aimed to focus on risk prediction instead.
Covering accidents from A to S
Water flooding in from damages of the haul in or below the water level usually does not spread from one compartment to another. This is precisely the point of the compartmentalisation of ships. To prevent the ship from capsizing, the flooded water needs to be distributed evenly into both sides of the ship. Thanks to the experiments conducted in the water technology laboratory in Aalto University, the progression of the flooding in the flooding channels can now be accurately modelled. (IMG)
The mathematical modelling and simulation of the probability and the progress of capsizing require experimental research as well.
– The major source of uncertainty in predicting capsizing is the information on the extent of flooding, says Andrzej Jasionowski from the University of Strathclyde who calculated the probabilities of capsizing in FLOODSTAND.
There are numerous uncertainties affecting the capsizing process: wave height, weather conditions, cargo on board, water tightness and stamina of the compartment structures, to name only a few. To get hold of these and render them as calculable risks, complex calculation of statistical probabilities is needed.
– Still, even for the finest of models, something remains out of reach – simply because models always oversimplify reality, reminds Risto Jalonen.
On the other hand, thanks to the achievements of project FLOODSTAND, it is now possible to replace many arduous and time-consuming experiments with mathematical calculations.
– We have also reached a new level in the research of the safety of cruise ships; we are in a good position to proceed, confirms Jalonen.
See the website of project FLOODSTAND: http://floodstand.aalto.fi
For further information please contact:
Project manager Risto Jalonen
Tel. +358 9 470 23477, risto.jalonen[at]aalto.fi
Aalto University
Department of Applied Mechanics, Marine Technology
Professor Pentti Kujala
Tel. +358 9 470 23484, pentti.kujala[at]aalto.fi
Aalto University
Department of Applied Mechanics, Marine Technology
Professor Jerzy Matusiak
Tel. +358 9 470 23480, jerzy.matusiak[at]aalto.fi
Aalto University
Department of Applied Mechanics, Marine Technology
