Hong Kong shipowners have intensified calls to improve carrier safety following the latest in a spate of cargo-vessel sinkings.
The 3,986-tonne Triumph Kaohsiung sank near the coast of Japan on Monday night with the loss of six crewmen. The ship, which was carrying 20 mainly Chinese crew members and a cargo of steel, was heading for Kaohsiung from Pohang, South Korea. One man is still missing.
The Hong Kong Ship Owners Association is calling for a more comprehensive approach to studies on the safety of the world's shipping fleet, particularly bulk carriers, even though structural enhancements would increase capital expenditure and operating costs.
Studies into bulker safety are centred on hatch-cover failures, but association director Arthur Bowring said the probes should be extended to examine vessel side-shell failures caused by stress, fatigue and erosion.
'Our technical subcommittee [has] made the point that damaged hatch covers, which indicate the extent of failure, are rarely seen, while damaged or loose side frames are an increasingly common occurrence, especially on older [large bulk carriers],' Mr Bowring said.
More than 100 Panamax bulkers are owned and commercially managed in Hong Kong. Of the larger bulk carrier market, more than 20 per cent of the world's vessels over 140,000 deadweight tonnes and less than 10 years old are owned by SAR interests.
Two recent events have turned the spotlight on bulker hatch covers. In December, the 1983-built, Cypriot-flagged Christopher was lost with all 27 crew near the Azores, about 1,000km from the coast of Morocco. The loss in 1980 of the 294m Derbyshire, with all 44 crew members, again brought their safety into question when the latest in a series of reports was released 15 months ago.
A British High Court judge, Justice Coleman, attached the blame for its loss on flooding caused by hatch-cover failure, an assessment he made last month of the Christopher disaster before rounding on ship classification societies for their continued failure to improve safety standards.
'How many more Derbyshires and Christophers will it need for the societies to get their act together?' he asked Lloyd's List.
The four-year-old Derbyshire went down so quickly in a typhoon near the coast of Japan that no distress signal was sent.
Mr Bowring said another bulker nemesis, side-frame failure, could be caused by corrosion of the weld which attaches the frame to the side shell. It can also happen when the frame bends from cargo weight or the force of waves against the vessel's side.
Force 10 winds and 15m waves pummelled the Christopher after an engine failure left the vessel without power.
Critics said the problem lay with the classification societies, which offered differing interpretations of metal fatigue lifespan and corrosion margins in the absence of global standards.
Varying degrees of reinforcement for vessels allow the builders to vary the price for similar ships, which attracts cash-strapped or cavalier owners trying to gain a commercial advantage. However, if structural reinforcement is universally mandated at design or added to existing vessels, Mr Bowring said no commercial advantage would be lost or gained.
'If everyone has to pay an additional US$1 million to US$2 million, then there is no competitive advantage. It's when an owner takes it upon himself to make the changes that the advantage is lost because the ships are more expensive, heavier and cost more to operate,' he said.
A spokesman for the International Association of Classification Societies, some of whose members have been accused of putting commerce before safety, last month said unified class requirements were 'already well on the way to formation', but guidelines remained on the drawing board.
Mr Bowring said: 'The loss of these ships and, more importantly, the lives of the seafarers serving on them makes this an issue that must be tackled with great urgency.
'While the studies into hatch covers must be continued, we ask that urgent attention also be given to the failure of side frames.'