Page 410 - Practical Design Ships and Floating Structures

385

safety is appreciated only after serious accidents have occurred. Design for safety, therefore, should
include risk to human life and risk to environment. Risk management should, therefore, be an integral
part of the holistic design approach. In the maritime sector, tragic accidents causing environmental
disasters have focused world opinion on ship safety and environmental protection through the
introduction of the International Safety Management code, (ISM).

The Factor of Safety commonly used in Engineering Design should, therefore, include not only safety
of the structure but should also take into account risk to human life and risk to environment, as
follows:
Y = 7x .7Y .Yz
y = Total Factor of Safety
'yx = factor taking account of the safety of the system
yy = factor taking account of the risk to human life
yz = factor taking account of the risk to ecology

It is evident that the irrational increase in the magnitude of L-2 total Factor c ifety of ship structure
will not only reduce the probability of structural failure, the cost of failure, the harmfil impact to the
environment but will also increase the initial cost of ship structure through the irrational use of
materials and resources. This indicates clearly that the magnitude of the Factor of Safety should be
rationally selected so as to satisfy the requirements of safe, ecology, economy and sustainability.

7 RISK MANAGEMENT
The course on Risk Management should cover hazard assessment, risk analysis, development of
accidental scenarios that could potentially lead to fatalitidinjuries, development of methods and
actions to reducdprevent risk, calculation of risk taking into account the likelihood of the scenario and
the probable negative consequences. Risk assessment is the process of assigning magnitudes and
probabilities to adverse effects resulting from human activities. Risk could be assessed by using the
probability density hnctions of both Demand and Capability. In this case the options to reduce risk are:
increase capability (sometimes very costly), decrease demand (sometimes not feasible), decrease
variability and uncertainty of capability (possible), decrease uncertainty of demand (not always
feasible).

8 ENVIRONMENTAL PROBLEMS

The course on Environmental Problems should cover the main types, causes, scope, consequences,
prevention, reduction and control of the negative environmental impacts. The impact of industry on air
pollution, water pollution, (rivers, coastal water, seawater, ground water, lake water), noise pollution,
climate change, ozone depletion, etc. should also be addressed. The course should clearly indicate
the consequences of irrational use of resources, expected climate change due to the increase of
greenhouse gases, etc. The contribution of the shipbuilding and ship repair industries to the local,
regional and global environmental problems should be also introduced and highlighted. Unfortunately,
there is very limited data available on energy consumption in the various stages of ship production.
Also, there is scarce data available on the various types of the negative environmental impacts
resulting from the different stages of ship production.