Time Domain Simulation of Accidental Flooding of RoRo Ships

Santos, Tiago A. R (1999) Time Domain Simulation of Accidental Flooding of RoRo Ships. MSc(R) thesis, University of Glasgow.

Abstract

RoRo ship accidents have become one of the most challenging engineering problems in the field of Naval Architecture. A large number of research programmes have been undertaken in several countries with the objective of improving the safety of these vessels. These investigations have allowed the conclusion that the main problem with this type of vessel is its poor damage stability. In this work, the main developments of the principal particulars, characteristic ratios and general arrangement of this type of vessel are studied, with the objective of determining the reasons for the damage stability problem. The most significant accidents that have occurred with passenger RoRo ships (European Gateway (1982), Herald of Free Enterprise (1987) and Estonia (1994)) are also reviewed. Some of the solutions that have been proposed in the open literature to solve the damage stability problem of passenger RoRo ships are indicated. The main steps in the development of the International Maritime Organisation subdivision and damage stability requirements are also reviewed and discussed. The time domain simulation of ship behaviour while flooding is identified as a useful technique to study the accidents that have occurred with this type of ship and to gain insight into the fundamental physical mechanisms governing RoRo capsize. A state-of-the-art review of the literature on RoRo damage stability model experiments and damaged ship motions simulation is performed. Based in that research, a theoretical model of damaged ship behaviour in calm water and in the absence of wind and forward speed is developed. The ship hydrostatic properties are obtained using a pressure integration technique. A theoretical model of the ship flooding process is also developed, comprising both the accidental flooding of the ship compartments by seawater and the cross flooding of compartments. These theoretical models are then implemented in a computer program. Finally, a general numerical model of ship geometry and loading, used to perform the simulation of its damaged behaviour, is described and a systematic technique to generate this model is presented. The hydrostatic properties calculated by the computer program using the pressure integration technique are validated through comparison with a software package. The numerical models of the barges and ship used to test the program are then presented and described. The time domain simulation results are validated agains quasi-static results for the flooding of a simple barge. The results are further validated by studying the influence of a number of parameters on the simulated motions and flooding of this barge. The results of a number of small-scale model experiments performed at the Glasgow University Towing Tank to investigate the major parameters influencing a physical phenomenon known as transient asymmetric flooding are presented, discussed and compared with simulation results. Finally, the European Gateway accident (1982) is modelled and simulated. The results of this simulation and its implications are discussed. A number of general and specific conclusions relating both to the present situation in what regards the damage stability problem of RoRo vessels and the current research programme are drawn. The pressure integration technique is a viable technique to calculate the hydrostatic properties of damaged ships and is susceptible of being used in a time domain simulation of damaged ship motions. The time domain simulation is a promising technique to analyse the behaviour of flooding RoRo vessels. Transient asymmetric flooding was observed during the experimental work and was reproduced using the time domain simulation. The simulation of the European Gateway accident allows the conclusion that the transient asymmetric flooding might have been the cause of this accident, but the precise influence of this phenomenon is difficult to evaluate accurately. Further large-scale model experiments are required to properly calibrate and validate the time domain simulation, especially the flooding model. Finally, based in the previous conclusions, areas for future development of this research programme are indicated.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Additional Information: Adviser: Carlos Soares Guedes
• Keywords: Naval engineering
• Date of Award: 1999
• Depositing User: Enlighten Team
• Unique ID: glathesis:1999-75927
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 19 Nov 2019 17:26
• Last Modified: 19 Nov 2019 17:26
• URI: https://theses.gla.ac.uk/id/eprint/75927