An integrated approach to naval ship survivability in preliminary ship design

• Main Author: Piperakis, A. S.
• Published: University College London (University of London) 2013
• Subjects: 621
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.626289

Alongside deploying weapons and sensors what makes a warship distinct is survivability, being the measure that enables a warship to survive in a militarily hostile environment. The rising cost of warship procurement, coupled with declining defence budgets, has led to a reduction in the number of ships in most western navies. Moreover, cost cutting is often aimed at aspects which may be difficult to quantify, such as survivability, and can lead to potentially inadequate designs. Innovation in both the design process and the design of individual ships is, therefore, necessary, especially at the crucial early design stages. Computer technology can be utilised to exploit architecturally orientated preliminary design approaches which can address innovation early in the ship design process and in issues such as survivability. A number of survivability assessment tools currently exist; however, most fail to integrate all survivability constituents (i.e. susceptibility, vulnerability and recoverability), in that they are unable to balance between the component aspects of survivability. Some are qualitative, therefore less than ideal for requirement specification, others are aimed towards the detailed design stages where implementing changes is heavily constrained or even impractical. Since a ship’s survivability is dependent on layout, the approach adopted in this research takes advantage of an architecturally orientated ship design approach applicable to early stage design. Such a method is proposed and demonstrated on five combatant (including a trimaran configuration) and two auxiliary ship design studies. The proposed method combines various tools used by UCL and the UK Ministry of Defence, as well as a new approach for recoverability assessment and, therefore, tackles difficulties currently associated with the latter (e.g.: lack of data, human performance and time dependence) by using weighted performance measures. An overall approach for survivability assessment has been applied across the range of designs produced and conclusions drawn on their relative merits for overall survivability. The approach and implications of the integration of survivability assessment in the preliminary ship design stages, as well as the identification of major survivability design drivers, are discussed. Through the identification of problematic topics, areas for further research are suggested. It is envisaged that this research will assist in developing the design process of what are, according to Captain C. Graham, USN, “the most complex, diverse and highly integrated of any engineering systems” produced today on a regular basis.