Page 31 - Practical Design Ships and Floating Structures

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vessel.

Lessons have been learnt from the losses of Leader L and Erika in recent years that ships under poor
maintenance will pose great threat to safety at sea and marine environmental protection.

Statistics show that 80% of marine accidents are caused by human elements, which has been widely
accepted among the maritime world.

Maritime safety chain provides a sound base for prevention of marine accidents. To ensure chain is
working well, efforts must be make in all associated areas, such as ship and offshore installation design
standard, quality assurance audit, management of maritime administrations and recognized
organizations, training and examination of seafarers. Regional PSC MOU (Port State Control
Memorandum) has also played an active role in promoting maritime safety and environmental
protection.

Ship age is another key element leading to marine accidents. Therefore, safety control of ships within
her life span is put on the top of the agenda. There is detailed analysis of the age of the world fleet as
follows.

The youngest fleet is container fleet, 50% of which are under 5 years of age. Bulk carrier fleet is older,
30% of which are under 5 years and the average age is below that of the total world fleet. General
cargo ship fleet comes last, 7% of which are under 10 years of age and only 2% under 5 years. This
implies that general cargo fleet is shrinking and will be gradually replaced by containers including
semi-containerships and multi-purpose vessels. The same thing happens to refrigerator ships. More
seriously, world passenger ships are aging rapidly, 44.3% of which are above 25 years. Although there
have been new constructions in the near decade, however the situation can not be changed quickly.

To solve the above problems, actions must be taken in two aspects. One is that new construction
standards should be reviewed and improved, such as requirements for tanker to have double hull, and
requirements regarding longitudinal strength, local strength including transverse bulkhead and double
bottom, bowkern door of roho ships. The other is to review the technical status of existing ships
including survey scheme and inspection method. Due to the implementation of IMO resolutions
concerning transverse bulkhead between No.1 and No2 holds and new strength requirements for
double bottom of No. 1 hold of bulk carriers, bulk carrier losses have been drastically reduced.
Requirements for longitudinal strength and fatigue strength of tankers are under review. Enhanced
Survey Program (ESP) of bulk carriers and tanker as well as Condition Assessment Scheme (CSA) to
tankers will come into force shortly. The revised 13G of MARPOL will lead to the fact that a large
number of tankers will be phased out.

It is true that any accidents will bring about the improvement of ship and offshore installation safety
standards, design standards and management. Accidents are the driving force of better safety and
environmental protection standards.