While it is untrue and simplistic to say that old ships are automatically unsafe ships, the statistics show that there is a definite correlation between age and accidents. Old ships suffer more from corrosion than new ones. They tend to break down more often. They require much more maintenance, which is not always given when most of the world is in recession and freight rates have plummeted. The second aspect of an ageing fleet is less obvious but just as serious. Shipping technology is evolving rapidly and the ships built today are constructed to much higher safety and pollution prevention standards than those built twenty or even ten years ago. Every time the regulations are changed, the "safety gap" grows wider.
"Grandfather clauses" which allowed amendments to regulations to apply only to new ships have been adjusted by the International Maritime Organization. Certain modified safety standards have to be completely introduced by the end of 1994, and others phased in between 1994 and 2000. In particular, from 1995 the new requirements will be extended to existing tankers not later than 25 years after the date of delivery; in other words, tankers built in 1970 or before will have to be converted immediately. The cost of converting these ships will be high and it is expected that many will be scrapped and replaced. According to an estimate by the Japan Maritime Research Institute, 54% of the world's existing tanker tonnage could be scrapped between 1993 and the end of the century.
In the 1970s the average age of a ship was about 8 years. In 1993 it is about 15. A 1990 Lloyds Register report drew attention to the aging oil shipping fleet. Most oil tankers are now between 10 and 20 years old. There are double the number of incidents involving machinery and hulls among ships in the 15-to 20-year-old range, while fire outbreaks multiply sixfold.