http://www.boston.com/dailyglobe2/124/nation/Cause_of_submarine_disaster_is_mystery+.shtml
Cause of submarine disaster is mystery
By Indira A.R. Lakshmanan, Globe Staff, 5/4/2003
BEIJING -- When submarine No. 361 descended on a training mission
two weeks ago, a malfunctioning diesel engine may have sucked the
oxygen out of the hull, claiming the lives of all 70 crewmen within
two minutes, a senior Chinese Navy official said yesterday.
All the victims were found at their posts, and there were no signs
of struggle, suggesting that death came upon the men quickly,
according to the official, who spoke on condition of
anonymity.
The Chinese military publicly attributed the tragedy to
''mechanical failure,'' giving no further explanation in a brief
announcement Friday night. But Western naval specialists familiar
with diesel-powered submarines said the official's account was
plausible.
According to the navy official, the submarine had charged its
batteries from its diesel engine at the surface in preparation for
descent. Diesel power is switched off in preparation for descent
because diesel requires oxygen to burn, the specialists said.
In this case, mechanical failure is believed to have caused the
diesel power to continue running, depriving the hull of its oxygen
and suffocating the crew, the official said.
''That is very plausible, and I'm inclined to believe that's what
happened,'' said retired admiral Lloyd ''Joe'' Vasey, who served 36
years in the US Navy, including a dozen aboard diesel-powered
submarines.
In a telephone interview from Honolulu, where he founded the
Pacific Forum with the Center for Strategic and International
Studies, Vasey said that ''the first thing you do when you dive is
you shut off the diesel because it sucks up a lot of air, switch to
battery power, and close the hatch. People don't forget to shut it
down,'' he said of the diesel engine, which in Ming class
submarines is easily shut off.
Mechanical failure of the engine, air induction valve in the engine
room, secondary air ducts, or a gasket are possible explanations,
he said.
''But it's possible we may never know the cause,'' Vasey
said.
The accident occurred during a training mission on April 16, the
official said, but was not discovered by the navy until 10 days
later, when the submarine crew did not contact their base as
expected. The crew had been under instructions to maintain radio
silence during training to practice disguising their location from
detection by enemy intelligence.
Ming class submarines can go 60 days without resupply, according to
Jane's Defence Weekly.
The crew had been training in the Neichangshan Islands off the
coast of northeastern Shandong and Liaoning provinces.
It is rare for China to release any news of military accidents,
making the announcement, even if belated, striking. In the 1980s, a
destroyer is believed to have exploded near the southern island of
Hainan, killing about 100 crew members in what is thought to be the
nation's worst naval accident in the last 50 years. That incident
was never officially reported.
Western analysts said the disclosure suggests that President Hu
Jintao's pledge to promote openness in government and media could
be genuine. Smarting from global criticism over its coverup of
severe acute respiratory syndrome, China might be more inclined to
release bad news now rather than have it leaked by an insider,
analysts said. An indignant military doctor publicized the hidden
cases of SARS in hospitals.
The No. 361 submarine was built in 1995, making it one of the newer
of the Ming class that China produced from 1971 to 1996. Intended
for patrols and coastal defense, it is copied from the decades-old
Soviet Romeo class, which was based on a German U-boat produced in
1944.
The Ming class is considered obsolete by the Federation of American
Scientists, but Vasey said he did not see any reason for China to
retire its fleet of Ming class submarines, now estimated at 13,
because ''accidents can happen to any subs.''
But James Clay Moltz, a research professor at Monterey Institute of
International Studies in California, said the Ming class has had
problems before. One of the earliest produced was scrapped because
of a fire.
In a telephone interview, Moltz said that No. 361 was the only Ming
class submarine built at Hudong Shipyard, suggesting there may have
been some engineering differences in this boat that contributed to
the malfunction.
The Ming class submarines are 249 feet long and 25 feet wide, able
to submerge to 984 feet and travel at 18 knots underwater. They are
equipped with eight torpedo tubes for 16 torpedoes or 32 mines,
Chinese military sources say. They usually hold nine officers and
46 sailors, suggesting that other technicians or staff officers
were aboard for this exercise.
The accident highlights vulnerability in China's aging fleet of
domestic and Russian submarines, estimated to number around 90.
Submarines are tactically useful for China, especially to enforce
its claim on the island of Taiwan, because they are difficult to
detect, and unseen submarines are a powerful deterrent to any
enemy.
