Page 38 - Practical Design Ships and Floating Structures

Practical Design of Ships and Other Floating Structures 13
You-Sheng Wu, Wei-Cheng Cui and Guo-Jun Zhou (Eds)
0 2001 Elsevier Science Ltd. All rights reserved

STRUCTURAL SAFETY OF SHIPS

Donald Liu

Senior Vice President
American Bureau of Shipping
Houston, Texas, USA

ABSTRACT
The topic of this lecture is the Structural Safety of Ships. This is a very broad topic and this lecture
will focus on tankers and bulk carriers, two ship types that have been the subject of structural safety in
recent years. It is interesting to explore the motivating forces behind many of the technical
developments that have affected structural design and safety of tankers and bulk carriers over the years
by considering:

What were the economic and regulatory forces driving technical change?
How did the industry respond to these forces?
Where do we stand today?
And, what are the implications for the future?

KEYWORDS

Structural safety, Tankers, Bulk carriers, Human element, Casualties, Risk-based safety standards.

1 HISTORICAL PERSPECTIVE

I would first like to give a historical perspective on how the design and safety of tankers experienced
the greatest changes during the last 40 years.

I will begin with the 1960’s and 1970’s, which were a time of incredible growth in the field of ship
technology, particularly in tanker design. This growth was economically driven as it was a period of
rapid developments in the economies of Europe, Japan and America.

In the decade of the 1960’s oil consumption increasing at more than 7% annually. As a result tanker
demand increased an annual average of more than 12%.
These economic driving forces promoted the most dramatic changes in tanker design that the marine
industry has ever experienced. The 50,000 dwt super tanker became the 250,000 DWT VLCC and
500.000 DWT ULCC.