4
T. Soomere
(of failure or accident) and the properly quantified severity C a (cost or consequence)
of this disaster:
R = P a × C a .
(1.1)
This notion of risk, called the risk equation below, is commonly used in natural
sciences, engineering and industry. The dawn of this concept stems from coastal engineering and management efforts during the planning of the immense Delta Works
infrastructure. After the devastating storm surge in February 1953 that killed 1,835
people in the Netherlands, the Dutch government triggered the construction of an
impressive bulwark megastructure, the Delta Works, to reduce the country’s flood
vulnerabilities.
The most visionary aspect of the Delta Works in our context is the statistical
approach that guided the designs. The novelty of the Dutch decision was to include
both the properties of storms and the economics of the Netherlands. With the help of
renowned mathematician David van Dantzig, the safety levels were calculated using
the risk equation (1.1) to produce a sequence of economically rational public-safety
decisions. This kind of risk analysis is common today in many fields of science and
engineering but back in the 1950s, accounting for the projected cost of damage was
novel. Dutch law now requires this principle to be used to determine the strength of
flood defenses throughout the country (Wolman 2008).
While the majority of the research in marine traffic risk has been focused on
the probability (Fowler and Sørgård 2000; Soares and Teixeira 2001; Goerlandt and
Kujala 2011, to name a few), the use of this notion is gradually increasing in the
analysis and modelling of such risks (Montewka et al. 2011).
Both factors on the right-hand side of the risk equation have been massively
addressed in the scientific and technical literature. For example, the use of contemporary navigation devices and detailed charts, the overall improvement of the
construction of ships to withstand the forces of nature, the implementation of realtime control through vessel traffic systems, etc., have considerably decreased the
probability P a of ship accidents. In spite of all these developments, however, major
offshore accidents continue to happen with some frequency. Although our understanding of loads that may occur during severe storms or accompany an ice attack
(Kujala and Arughadhoss 2012) is continuously improving, it is economically unfeasible to design all the ships to fully resist such forces on all occasions. Also, a
ship or offshore structure is such a complicated system that even minor defects in
its production or errors in its design may result in a significant failure (e.g., Collins
et al. 1997). Moreover, a human error or misbehaviour cannot be totally excluded.
As there is no way to stop ship traffic or to avoid extensive use of the marine
space for other purposes, society has to cope with the associated dangers. This implies that, along with methods to properly quantify (Goerlandt and Kujala 2011) or
decrease the probability of misfortunes, an equally important task is to develop ways
for the mitigation of the potential damage that may occur. This can be achieved, for
example, by specific improvements in ship construction so that minor groundings
and collisions will not result in pollution. The key development here has been the
introduction of double-hull tankers (Paik 2003). This advance has considerably reduced the number of oil spills due to tanker traffic (Glen 2010).
T. Soomere
(of failure or accident) and the properly quantified severity C a (cost or consequence)
of this disaster:
R = P a × C a .
(1.1)
This notion of risk, called the risk equation below, is commonly used in natural
sciences, engineering and industry. The dawn of this concept stems from coastal engineering and management efforts during the planning of the immense Delta Works
infrastructure. After the devastating storm surge in February 1953 that killed 1,835
people in the Netherlands, the Dutch government triggered the construction of an
impressive bulwark megastructure, the Delta Works, to reduce the country’s flood
vulnerabilities.
The most visionary aspect of the Delta Works in our context is the statistical
approach that guided the designs. The novelty of the Dutch decision was to include
both the properties of storms and the economics of the Netherlands. With the help of
renowned mathematician David van Dantzig, the safety levels were calculated using
the risk equation (1.1) to produce a sequence of economically rational public-safety
decisions. This kind of risk analysis is common today in many fields of science and
engineering but back in the 1950s, accounting for the projected cost of damage was
novel. Dutch law now requires this principle to be used to determine the strength of
flood defenses throughout the country (Wolman 2008).
While the majority of the research in marine traffic risk has been focused on
the probability (Fowler and Sørgård 2000; Soares and Teixeira 2001; Goerlandt and
Kujala 2011, to name a few), the use of this notion is gradually increasing in the
analysis and modelling of such risks (Montewka et al. 2011).
Both factors on the right-hand side of the risk equation have been massively
addressed in the scientific and technical literature. For example, the use of contemporary navigation devices and detailed charts, the overall improvement of the
construction of ships to withstand the forces of nature, the implementation of realtime control through vessel traffic systems, etc., have considerably decreased the
probability P a of ship accidents. In spite of all these developments, however, major
offshore accidents continue to happen with some frequency. Although our understanding of loads that may occur during severe storms or accompany an ice attack
(Kujala and Arughadhoss 2012) is continuously improving, it is economically unfeasible to design all the ships to fully resist such forces on all occasions. Also, a
ship or offshore structure is such a complicated system that even minor defects in
its production or errors in its design may result in a significant failure (e.g., Collins
et al. 1997). Moreover, a human error or misbehaviour cannot be totally excluded.
As there is no way to stop ship traffic or to avoid extensive use of the marine
space for other purposes, society has to cope with the associated dangers. This implies that, along with methods to properly quantify (Goerlandt and Kujala 2011) or
decrease the probability of misfortunes, an equally important task is to develop ways
for the mitigation of the potential damage that may occur. This can be achieved, for
example, by specific improvements in ship construction so that minor groundings
and collisions will not result in pollution. The key development here has been the
introduction of double-hull tankers (Paik 2003). This advance has considerably reduced the number of oil spills due to tanker traffic (Glen 2010).