One of the most topical ship maintenance issues concerns the forthcoming IMO ban on tin-based anti-fouling paints. These protect immersed hull surfaces against the growth of organisms such as barnacles and algae, which greatly reduces fuel efficiency and speed. But the best coating systems contain volatile organic compounds such as tributyltin (TBT) and TBT self-polishing copolymers. Studies show that the tin released into the sea by TBT can be extremely harmful for marine life, for example causing adverse reproductive effects on shellfish such as whelks.

In the past there has been considerable demand for these paints because they offer a high degree of reliable and consistent protection against fouling, and hulls only need to be cleaned every five years as opposed to every three years for TBT-free alternatives. The progressive banning of these coating systems by 2008 means that alternatives have to be found.

Mr Telle says that paint producers are responding to the challenge and are well advanced with tests for new products. "The highly demanding development phase," he says, "requires significant long-term investment and the new paints must be proved to have no other side effects on marine life." A Norwegian programme involving the testing of TBT-free paints on 12 ships, which is being monitored by TRESHIP partner MARINTEK , should be completed by 2006.

The TRESHIP partners have also been investigating and comparing new methods for cleaning hulls such as hydro-blasting and vacuum blasting. The current technique of grit blasting has itself been criticised for the high levels of airborne and sometimes toxic dust generated.

While today's ships release significantly less oil directly into the sea than just a decade ago, they are still the biggest source of maritime pollution. It is estimated that shipping is responsible for 5-10% of the acid rain that falls in coastal areas, and even more around ports where more fuel is used during launching and landing manoeuvres.

Nitrogen Oxides (NO_x) and particles (unburned hydrocarbons) cause the greatest concern. For example, ships generate 45 grams of NOx per kilowatt of power generated compared to 5 grams for heavy goods vehicles. Sulphur Oxides (SO_x), which are directly related to sulphur content levels in fuel oil, are another harmful pollutant that the industry is working to reduce.

Research into the use of alternative fuels such as gas has been a key theme for TRESHIP. There is still a long way to go before gas turbine engines can compete with their diesel counterparts, but they could ultimately reduce NO_x and SO_x emissions by 80-90% without increasing overall fuel consumption. They are of course well suited to the needs of particular customers, such as national navies requiring ever-stealthier noise-free vessels, or luxury ferry operators concerned with the comfort of their passengers. The up-market cruise company Royal Caribbean , for example, has already put in an order with Chantiers de l'Atlantique in Saint Nazaire, France.

Recently agreed IMO regulations will not come into effect for several years, but public opinion and government policy agendas are pushing the industry to act sooner. The formal representation of shipping for the first time at the seventh session of the conference of the parties to the Kyoto climate agreement, held in Marrakesh in November 2001, is indicative of its commitment.

One of the next major challenges is the testing of hydrogen-based fuel cells on board ships. While the automotive industry has made considerable advances in this area, such technology will probably not be a regular feature on merchant vessels for another ten years. A bid for research funds has recently been submitted to the Commission, and the TRESHIP partners are eagerly awaiting a response.