Search operations to rescue more than 287 missing passengers from the stricken Sewol ferry in South Korea have been hampered by strong currents, poor underwater visibility and bad weather.
Speaking at a press briefing on 17 April, Kang Byung-kyu, South Korea’s minister of security and public administration, said that 500 divers, 169 boats and 29 planes had been mobilised to continue search operations. “Strong currents and the murky water pose severe obstacles,” he said. “We will do our best.”
Sewol was reportedly carrying around 470 passengers when she capsized and sank about 20km off the island of Byungpoong on South Korea’s south-west coast on Wednesday 16 April.
Passengers included around 30 crew and 89 regular passengers, as well as 325 high school students and 15 teachers from Danwon High School in Ansan, Seoul, who were on a field trip to Jeju island. While the South Korean Ministry of Security and Public Administration confirmed that 179 passengers and crew had been rescued, many of the schoolchildren are still missing. Nine deaths have been confirmed, while dozens of people have been injured.
It is not yet known what caused the incident, which led to onboard crew sending a distress signal from the ferry at around 9:00 am local time on Wednesday. Numerous survivors have reported hearing a loud thud before the 20-year-old vessel – which was built by Hayashikane Shipbuilding & Engineering in Nagasaki, Japan – began to shake, list and eventually sink.
Speaking to BBC News, naval architect Ian Winkle said it was likely that the ship had struck an underwater object at a relatively high speed, causing a tear to form along the hull of the vessel. Comparing the incident to the Costa Concordia accident, which occurred on 13 January 2012, Winkle explained that the ferry had probably taken in a large amount of water into the lower wing tanks, causing her to list at a 45- to 60-degree angle for a prolonged period of time. This then caused more water to fill the upper decks and eventually capsize the ship.
“Apparently this vessel would have been travelling at around 20 knots, which is quite fast, and if you hit something underwater at this speed, it’s likely to tear a long hole in the side of the ship,” said Winkle, explaining that if the heel of a vessel reaches a certain point, the wing tanks become ineffective. “Unfortunately it is almost impossible to recover from this, as ships are not designed to have tears in the side. Consequently, she's flooded rather more quickly than we would normally assume.”
According to Winkle, it was clear the vessel would roll and all measures to protect passengers should have been taken by the crew. “We would have expected the crew to launch all of the life rafts, which they didn’t do as they are all clearly strapped to the upper decks,” said Winkle. “The crew should also have aimed to get passengers away from the internal spaces because you can’t move around in these large spaces once the vessel reaches any level of significant heel. You would want passengers to line up on the side of the upper decks so they could at least slide down or get off as the vessel rolled over.”
The ferry’s captain was questioned at the Mokpo Coast Guard Office and was filmed by Yonhap news agency apologising for the accident. He said: “I am really sorry and deeply ashamed. I don’t know what to say.”
Owned by Chonghaejin Marine, the vessel is registered with the Korean Register of Shipping and has the capacity to carry up to 900 passengers. Chonghaejin Marine has issued a brief apology via local media but has since made no further comment.