The front section of an Iranian oil tanker that has been on fire for days off the east China coast has exploded partially, rescue boats are searching  for 31 missing sailors to retreat and sparking environmental concerns.

32 crew members, including 30 Iranians and two Bangladeshis, went missing after the tanker carrying 136,000 tonnes of oil  from Iran to South Korea collided with a Hong Kong-registered bulk freighter and caught fire on Saturday in waters about 160 sea miles east of the Yangtze River’s estuary.


Since then, Sanchi a Panama registered tanker  has been ablaze and drifting in the waters between Shanghai and southern Japan. So far, no survivors from the tanker have been found and only one body has been recovered. 21 crew members were recused by the Chinese ship.

The front side  of the tanker exploded on Wednesday. “Vessels at the scene have to stop putting out the fire and withdraw back to (a safe distance),” China’s Ministry of Transport said. “The fire extinguishing operation did not achieve the desired effect,”.

Chinese largest patrol ship Haixun 01 is fighting the fire after the explosion while organizing other vessels to move away.

According to the ministry, Japanese sea police arrived at the scene an hour before the explosion and established contact with Haixun 01. China’s Ministry of Foreign affairs said Wednesday that 12 vessels were searching for the missing sailors in the tanker’s vicinity before the explosion, and they are working to clean the spilled crude oil.

Since the crash, the tanker has been billowing thick plumes of black smoke. Officials worry that the explosion might sink the ship, releasing its 1 million barrels of oil into the water. The resulting spill would be about three times as big as the Exxon Valdez spill of 1989, one of the worst environmental disasters in history. “For now, burning might be good for consuming the leaked oil, but there will be some remaining for which disposal will be difficult,” Lin Boqiang, director of the China Center for Energy Economics Research at Xiamen University, told the Global Times.


Sanchi was carrying 1.36 lakh tons of condensate oil when it collided with CF Crystal, a Hong Kong-registered bulk freighter in waters about 160 nautical miles east of the Yangtze River estuary.

Experts are very much  worried because the ship is carrying condensate, an ultra light version of crude oil. Condensate is highly toxic and even more combustible than regular crude oil. It also is nearly colour less and odourless, which makes it difficult to detect.

Oil is usually not degradable, meaning the damage to the ocean would be long-term, he said.

Zhao Ruxiang, an expert with China’s Yantai Oil Spill Response Technical Centre, was quoted by the ministry as saying that a simulation test showed condensate oil in the water can evaporate so quickly that it will leave little residue – less than 1 percent after five hours. “It is toxic and volatile when exposed to air,” Zhao said.



The blast happened on board the tanker in the afternoon after rescue crews were working on the ship with foam in an attempt to put out the fire, China’s Transport Ministry (MOT) said in a statement on Wednesday.

The cause and damage to the tanker from the incident is not clear. The ship was carrying condensate, a highly flammable ultra-light crude, to deliver to South Korea when it collided with a Chinese freight ship on Saturday.

Dozens of rescue boats from China and South Korea have been battling strong winds, high waves and poisonous fumes to comb a 900-square-nautical-mile (3,100-square-kilometre) area for 31 missing sailors and tame the fire, amid growing concerns the listing ship may explode or sink.

Iran’s Navy joined the effort on Wednesday, a government official said, according to the Iranian Students’ News Agency (ISNA).

The lashing winds are expected to ease on Thursday, the MOT said.

The tanker Sanchi (IMO:9356608), run by Iran’s top oil shipping operator, National Iranian Tanker Co, collided on Saturday with the CF Crystal (IMO:9497050), carrying grain from the United States, about 160 nautical miles (300 km) off China’s coast near Shanghai.

The Sanchi was carrying 136,000 tonnes of condensate, equivalent to about 1 million barrels and worth some $60 million. The Chinese government said late on Tuesday it had not found a “large-scale” oil leak, and the condensate was burning off or evaporating so quickly that it would leave little residue – less than 1 percent – within five hours of a spill. That reduces the chances of a crude-style oil slick.

Iranian officials said there was still a chance of finding survivors among the 31 remaining crew, who are all Iranian nationals except for two Bangladeshi citizens. The body of a crew member was found on Monday in the water near the tanker.

“If the crew have been able to reach some place like the engine room, then the chances of their rescue are high,” said Hassan Qashqavi, a senior Iranian foreign ministry official, according to ISNA.

Authorities and environmentalists worry though the ship is increasingly vulnerable to breaking up and sinking the longer the blaze rages. Still, the ultra light crude is highly volatile when exposed to air and water.

South Korea’s Ministry of Oceans and Fisheries warned on Wednesday the tanker could burn for up to one month, potentially expelling the tanker’s bunker fuel, or the heavy fuel oil that powers a ship’s engines and contaminating the waters.

“We believe flames would last for two weeks or a month considering previous cases of oil tank accidents,” said Park Sung-dong, an official at the ministry.

Bunker fuel is the dirtiest kind of oil, extremely toxic when spilled, though much less explosive.

Fuel oil is relatively easy to contain because volumes are lower and its viscosity means it’s easier to extract from water, but even small volumes can hurt marine life.

“The problem is the ship’s heavy bunker fuel,” said Chauncey Naylor, a U.S.-based director of emergency response and training at Tyco Corp’s oil-fire specialists Williams Fire & Hazard Control, which is not involved in the clean-up.