Reconfiguring Passenger Ship Internal Environment for Damage Stability Enhancement

Abstract

The traditional risk control option adopted in naval architecture to meet safety-related objectives is by regulations, targeting damage limitation, nominally instigated in the wake of maritime accidents claiming heavy loss of life. These primarily concern the introduction of watertight bulkheads, i.e., permanent (passive) reconfiguration of the internal ship environment to enhance damage stability. 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. However, traditional flooding protection through watertight subdivision, to an extent dictated by IMO regulations, 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 and with design stability margins progressively eroding, stability management is unsustainable, leading to loss of earnings at best. The need for managing the residual risk through active intervention/protection over the life-cycle of the vessel drives industry to searching and adopting a new normal. This new normal is the innovation being explained in this paper by addressing safety enchantment through a systematic reconfiguration of the ship environment for passive and active protection in flooding accidents. In this respect, the “design-optimal” internal arrangement of a vessel, is adapted and reconfigured, using passive and active containment systems for flooding incidents, in the form of high-expansion foam products. The innovation is briefly explained, claiming transformational reduction in flooding risk in the most cost-effective way available. To support wider understanding and appreciation for the latter, the paper critically reviews the whole evolution of internal ship space reconfiguration, chronologically and systematically, concluding that new technological developments and breakthroughs will bring sustainable changes to the traditional evolutionary maritime safety enhancement.

A Review of Methods for Modelling Flooding, Its Progression and Outcome in Damaged Ships

“…Following a damage identification and outcome prediction, an emergency response by the crew is put in place (e.g., damage control). Though passive and active containment systems for flooding incidents-e.g., high-expansion foam products-have been proposed [130], active measures by the crew like counter flooding can be potentially assessed to determine their outcome using the tools described in Section 5.1. These types of actions, targeting flooding mitigation for stability enhancement in a damaged RoPax ship, were studied recently by Valanto [23].…”

Alternative Design Approach for Ship Damage Stability Enhancement Based on Crashworthiness

“…The system was devised by Vassalos and Paterson, and the University of Strathclyde has the patent (Patent No.PCT/ GB2017/050681). The permeability of two wing compartments filled with foam is assumed as 0.05, which was proposed by Paterson (2020). Considering zero permeability for internal safe spaces, the total permeability of the target zone may be between 0.00 and 0.05, which means almost no flooding will occur in the target zone as a "Never flooded zone" for this RCO.…”

“…For the cost estimation of each RCO, the unit cost utilised in the EMSA III project in Table 11 has been adopted considering an exchange rate of 1.1 between Euro and USD in 2015. In particular, for foam filling, 600 € /m3 and 25 kg/m3 have been considered based on the relevant study by Paterson (2020). For the additional fuel cost due to the increased weights of each RCO, the wetted area increases have been calculated from NAPA, and it was assumed that it directly affects ship fuel consumption as friction resistance of the ship as a function of the wetted surface area generally takes a majority of total ship resistance.…”