MT Sanchi

The incident

Following a collision with the Hong Kong-registered bulk carrier CF Crystal, en route for China, the Iranian oil tanker MT Sanchi, headed for South Korea, caught fire on 6th January 2018, around 300 km off Shanghai. The collision occurred in China's most important fishing grounds. Driven by violent winds and strong waves, in adverse weather conditions, the vessel drifted for over a week. On 10th January, part of the oil tanker exploded and extinguishing operations, led by the Chinese Government, were suspended.  On the 13th, fresh attempts were made to put out the fire and a Chinese rescue team boarded the vessel and recovered the voyage data recorder from the MT Sanchi. On 14th January, the whole tanker exploded and sank in waters 115 m deep, off the Japanese Ryukyu Islands. Of the MT Sanchi's 32 crew members (30 Iranians and two Bangladeshis), 3 bodies were found and the remaining 29 were reported missing.

The pollutant

After the vessel sank, part of the 136,000 tonnes of condensate still leaking from the ship burnt at the surface, generating an impressive smoke cloud.  On 15th January, the fire went out and, given its low viscosity, the condensate largely evaporated and/or spread widely across the sea surface to form a thin film of sheen with a surface area estimated by the Chinese authorities at up to 300 km².  Despite strong surface agitation, promoting the natural dispersion of the condensate, fragmented slicks were observed by the Japanese Coast Guard on the 16th, 27 km north of the collision site. On 21st January, the oil spill was estimated by the Chinese State Oceanic Administration at around 330 km². From the 22nd, the slicks were less apparent at sea but on the 23rd, around twenty boats nevertheless continued to survey the area. On 2nd February, the first tarballs, which may have come from the burn residues of the condensate or heavy fuel oil, washed up on the shores of Japan's Southern Islands.  By 23rd February, at least 16 islands were affected and 90 tonnes of waste had been collected.

The Chinese authorities had great difficulty in predicting the environmental and health impacts of this spill due to conflicting information on the behaviour of the substances spilt and the sometimes contradictory results obtained from drift modelling.

Response

The Chinese Government was quick to implement search and rescue operations in collaboration with South Korea and Japan to locate the tanker's crew. However, given the blaze and the heat and thick smoke emitted, rescue operations proved complicated. Some 15 vessels which were in the area at the time were involved in rescue, oil recovery and fire extinguishing operations. The bulk carrier, which was transporting grain, did not suffer any major damage and was taken to Zhoushan port after all 21 crew members had been evacuated. The Chinese authorities maintained a major airborne and shipborne surveillance effort in order to monitor the evolution of condensate slicks and leaks of bunker fuel, a heavy, viscous oil.

Based on information released by the China Maritime Search & Rescue Centre, the Chinese website www.eworldship.com announced the following figures for the 60-odd response operations conducted at sea involving all sorts of boats:

• 27 tonnes of dispersants used
• 440 tonnes of sorbents used
• 800 metres of booms deployed

The website also specifies that a ROV inspected the wreck for 2 days and observed a breach at the point of collision, on the right-hand side of the MT Sanchi's hull. The breach was triangular and 35 metres long at the widest part.

This was above all a human tragedy.

Yet it was also the largest known condensate spill into the environment to date. The very volatile crude oil burnt for around 10 days, causing major atmospheric pollution. The share of condensate which was burnt in the air and the share which spread across the sea surface are unquantifiable.

The Chinese maritime authorities were quick to take action in the incident area, but did not disclose any information, in particular as concerns the environmental consequences. The Japanese and Taiwanese media also offered very little information.

The economic impact on fishing could be very high and should be covered by the concerned parties' P&I club. According to estimations by the National Iranian Oil Company (NIOC), the financial damage caused by the MT Sanchi represents approximately US$110 million: US$60 million for the cargo and US$50 million for the ship itself.

Conclusion

This was a rather unusual maritime incident in that:

• the collision occurred between two modern vessels, the MT Sanchi, built in 2008, with a double hull and the bulk carrier CF Crystal built in 2011
• the oil pollution was located at the maritime boundary between two countries: China and Japan
• the area in which the collision occurred is a busy shipping area
• the pollution was worse for the atmosphere than for the marine environment
• condensate is a product whose impact on the environment (air and sea) is poorly known. The effects of the heavy fuel oil on the environment are known however and are detrimental to the environment.

Further information

Video of the spill. Formation of oil slicks at sea around the oil tanker on 15th January 2018 and blaze aboard the MT Sanchi