The tug TNS Catcher, which capsized off Busan, is believed to have been in an accident while turning right as it was towing a container ship. The Korea Coast Guard significantly expanded the search area on the second day of the operation to find the six missing people.
Busan Maritime Police Station held a briefing on the 3rd and released the initial findings of the investigation.
A Busan maritime police official said of the cause of the accident, "Two tugs were towing from the left and right of the bow of the container ship and another one was pushing from the stern," and added, "(The bow starboard tug, TNS Catcher) is presumed to have capsized due to the hawser (towline) while changing course (turning) to the right."
The official added, "It appears to have capsized because the speed and timing did not match during the course change," and said, "It has not been confirmed whether it snagged on the towline."
The Korea Coast Guard ruled out the possibility that the tug and the container ship collided. It also explained that, considering the vessel's engine output and other factors, the towing operation itself at the time did not appear to be excessive.
Closed-circuit (CC) TV from the container ship released by the Korea Coast Guard that day showed the TNS Catcher turning to the right and then rolling to the left.
The 286-ton (t) tug TNS Catcher capsized at about 1:29 p.m. on the 2nd in waters about 9 km east of Oryukdo, Busan. At the time, it was towing the Liberia-flagged 66,332 t container ship M with other tugs.
Of the eight crew members, one Indonesian was rescued, but one Korean was found unconscious and died after being taken to a hospital. The remaining six are still missing.
The capsized TNS Catcher is believed to have drifted about 4.5 km northeast from the accident site before sinking, then moved about 0.8 km southwest again. The Korea Coast Guard found an object believed to be a vessel at about 8 p.m. on the 2nd on the seabed 6.5 km east of Songjeong Port and confirmed the TNS Catcher resting at a depth of about 87 m.
A Navy remotely operated vehicle (ROV) was then deployed for an underwater search, but visibility was only about 30 cm, and the missing were not found.
Taking into account the time elapsed since the accident, the Korea Coast Guard expanded the search area that day to 66 km wide and 40 km long. Dividing the search waters into 17 zones, it has deployed 24 ships and seven aircraft for a joint military-government search.
Seong Dae-hoon, chief of the Busan Maritime Police Station, said, "While conducting underwater searches using Navy ROVs, we also plan to explore methods that allow diving to the relevant depth," and added, "We will promptly and fairly determine the cause of the accident and accountability based on objective evidence and verified facts."
The Busan maritime police formed the "TNS Catcher capsizing incident investigation headquarters," with 41 investigators participating, to look into the circumstances of the accident. So far, six officials from the shipping company have been questioned, and data including the automatic identification system (AIS), voyage data recorder (VDR), and CCTV footage from the tug and the container ship have been secured.