Rescue crews yesterday continued their efforts to control the blaze on Iranian oil tanker Sanchi, which exploded and burst into flames 160nm off the east coast of China, after colliding with bulk carrier CF Crystal.
There were increasing worries that the tanker might explode and sink, official Chinese media said on Monday, citing experts from the rescue team. A 10 nm radius around the vessel has been established.
CF Crystal has been escorted to anchor near Zhousan.
Chinese state media CCTV showed footage on Monday of a flotilla of boats dousing the flames, while plumes of thick dark smoke continued to rise from the suezmax tanker.
China sent four rescue ships and three cleaning boats to the site, South Korea dispatched a ship and a helicopter, while a US Navy military aircraft searched an area of about 3,600 square nm for crew members. None has been found alive, while there were reports that one body had been found on the ship itself.
Sanchi was sailing from Iran to South Korea with 136,000 tonnes of ultra-light and highly volatile crude oil condensate. The collision occurred in waters not frequently used by large vessels like tankers, dry-bulk carriers or container ships. Most ships travel either closer to the Chinese coast in the west or more nearby to Japan in the east.
CF Crystal, which was carrying U.S. grain, suffered limited damage and all 21 crew members, Chinese nationals, were rescued.
Bad weather made it hard for the rescue crews to get access to the tanker, but toxic gas from the burning oil posed a major risk. Condensate mostly occurs as a by-product of natural gas production. It is usually composed of propane, butane, pentane or hexane but can also contain carbon dioxide, hydrogen sulphide, aromatics and naphthenes. When condensate meets water, it evaporates quickly and can cause a large-scale explosion as it reacts with air and turns into a flammable gas, the transportation ministry said on Monday.
Trying to contain a spill of condensate, which is extremely low in density, highly toxic and much more explosive than normal crude oil, may be difficult. When liquid, most condensate is colourless and virtually odourless. Surface spills of condensate are therefore difficult to detect visually, making them hard to manage and contain. Condensate is mostly used to make vehicle fuel, such as gasoline, and is sometimes called natural gasoline. It can also be used to dilute heavier crude oils before they are used as a feedstock in oil refineries, or to make products like plastic in the petrochemical sector. Whether escaped condensate causes an oil spill or not depends on whether it has vaporized, burnt off, or escaped in liquid form. When forming a spill, its toxicity and uncontrollability makes it particularly dangerous. However, it dissipates and breaks down more easily than heavier oils.
The tankers was also thought to have been carrying some bunker fuel.
The Shanghai Maritime Bureau’s navigation department said the collision did not affect traffic in and out of Shanghai.
A spokesman for South Korea’s Hanwha Total Petrochemical Co Ltd, which was due to receive the cargo, said it would use its own stockpiles to replace the lost cargo.
Norway-based marine insurer Skuld leads the hull insurance for Sanchi, it confirmed yesterday.
Sanchi is entered for P&I with Steamship Underwriting (Smuab), Eastern Syndicate, on behalf of Bright Shipping Ltd.
CF Crystal, owned by Changong Group HK Ltd care of manager Shanghai CP International Ship Management of Shanghai, China, is entered for P&I with Skuld on behalf of Changfeng Shipping Holdings Lim.