LIVES are being put at risk in Hong Kong waters by a mysterious cross-border paging service whose signal is jamming Marine Department radios, preventing it from alerting ships about to collide. China has been asked to urgently find and stop the signal cutting into vital maritime VHF channels, but has yet to respond. Interference from the service is being blamed for two cases on Tuesday when radar officers in the department's vessel traffic centre could not get through to captains in a bid to prevent two potentially major accidents, one involving a large cruise ship. None of the several hundred passengers aboard the 4,201-tonne Nan Hu was injured when it collided with the 2,283-tonne Shuang Feng Shan in the Tatong Channel in thick fog, damaging the decks of both ships. In an earlier incident, an liquefied petroleum gas carrier scraped along the side of a chemical tanker in the Ma Wan bend. The danger was spotted on department radars but frantic radio operators could not get a message through to the boats. Variable tones traced to Shenzhen and sounding like push button telephone codes have been heard sweeping across channels reserved under international conventions for Hong Kong's port operations and harbour pilots. When interference from the signal is at its height nothing can get through it. The department is bound under the conventions to only use certain channels, with local pager companies assigned frequencies far from interference range. ''Our radar equipment is some of the best in the world, with alarms telling us when ships are on collision courses, but if we can't get through to them it's useless,'' said Barrie Hird, Principal Marine Officer (Port Services). ''We're just lucky that Tuesday's accidents were relatively minor, but we do fear for what could happen in the future,'' he said. Gus Wong Man-hung, of the Office of the Telecommunications Authority, said he had been investigating for several weeks but the authority did not have the equipment to pinpoint the exact location of the signal. ''It is some sort of paging signal and it is across the border but we don't know if it's a private venture or official, and we don't have the equipment to decode the information,'' he said. ''We are still investigating and are waiting for replies from our Chinese counterparts. ''We just don't know what it is being used for or how strong it is but it could well be that a transmitter is faulty and broadcasting across different frequencies,'' he said. Mr Wong said Hong Kong's findings had been handed to senior officials in the Office of the Committee of the Radio Administration in Guangzhou. Hong Kong's Office had a long-standing tradition of good co-operation and he was hopeful of a quick response. Meanwhile, the Director of Marine Allan Pyrke yesterday raised concern at the number of mainland vessels involved in seven collisions when fog clouded the harbour on Tuesday. Of the 14 vessels involved, six were mainland registered with mainland crews, including the sand-barge which capsized after allegedly going the wrong way down a restricted shipping lane. The captain and first mate drowned. Two mainland passenger vessels were among those involved while a smaller wooden craft smashed into a local dredger at the Ma Wan bend yesterday. ''It could just be coincidence but it is something we will be raising firmly with our counterparts during regular meetings once investigations are completed,'' Mr Pyrke said. ''We hope our new campaign to get reports on near-misses will tell us not only the black spots, but who the offenders are.'' Preliminary investigations are under way into all the accidents.
