Reconfiguring the ship environment for damage stability enhancement

Student thesis: Doctoral Thesis

Abstract

It has often been said that, from a fundamental Naval Architecture perspective, the primary design objective to be achieved is for a ship to remain afloat and upright (safety-related objectives). This is particularly true in case of vessel flooding, where this objective becomes harder still. The traditional risk control option adopted in Naval Architecture to meet safety related objectives is by rules and regulations, targeting damage limitation, nominally instigated in the wake of maritime accidents claiming heavy loss of life. The first Merchant Shipping Act of1854 is the earliest known legal requirement addressing safety at sea and concerning watertight bulkheads, i.e., permanent (passive) reconfiguration of the internal ship environment to enhance safety. This has been the most common measure, manifesting itself in the wake of every serious flooding accident since the beginning, back in the 19th century. Notably, with accidents providing the main motivation, emphasis has primarily been placed on reducing consequences, i.e., on cure rather than prevention.The key reason for this, derives from the fact that the residual risk post flooding accidents is unacceptably high, meaning that the most-cost-effective way to reduce flooding risk is to target the residual risk. This being the case, the prevailing situation can be drastically improved through understanding of the underlying mechanisms leading to vessel loss and to identification of governing design and operational parameters to target flooding risk reduction more cost-effectively. On one hand, this necessitates the development of appropriate methods, tools and techniques capable of meaningfully addressing the physical phenomena involved. On the other hand, this nurtures wider understanding and wisdom. Safety is normally a compromise to vessel earning potential and, as public demand for higher safety standards grows, industry is forced to choose between viability of business and safety of customers. Unfortunately, in any such compromise, safety loses. However, the key reason for this is strongly linked to the traditional myopic focus on only permanent, designed-related safety measures, pertaining in particular to flooding incidents.Traditional flooding protection through watertight subdivisionis largely dictated by IMO regulations and has a physical limit which, if exceeded, a safety plateau is reached. This is currently the case and with damage stability standards progressively increasing, the safety gap between existing and new ships is dangerously widening. Adding to the problem is the progressive erosion of design stability margins, making stability management unsustainable and leading to loss of earnings at best. The need for monitoring and managing the residual risk through active intervention/protection over the life-cycle of the vessel drives the industry in searching to adopt a new normal. This new normal is the innovation being explored in this thesis, by addressing safety enchantment through a systematic reconfiguration of the ship environment for passive and active protection in flooding (and to some extent fire) accidents. In this respect, the “design-optimal” internal arrangement of a vessel, is adapted and reconfigured, using passive and active containment systems for flooding/fire incidents, in the form of high expansion foam products. Several case studies are being presented to explain and explore the safety-enhancement potential. This demonstrates transformational reduction in flooding/fire risk, in the most cost-effective way available.
Date of Award9 Oct 2020
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SponsorsUniversity of Strathclyde
SupervisorDracos Vassalos (Supervisor) & Evangelos Boulougouris (Supervisor)

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