The Taiwan Transportation Safety Board (TTSB) has released the final report on the investigation into the occurrence involving the container vessel Uni-Active, which was involved in a collision at Yangon Port, Myanmar.

At 1342 hours (local time) on May 14, 2025, the Taiwan-flagged container vessel Uni-Active (IMO No. 9130547, gross tonnage 14807, length overall 165.00 meters, beam 27.10 meters, container capacity 1,296 TEU), while conducting a turning maneuver during departure within the Yangon River channel, Myanmar, had its stern collide with three vessels moored abreast at the pier. As a result of the occurrence, Navy 217 and Dana Hlaing sank, and Annawar Aung 8 sustained hull damage, but no injuries or pollution were reported.

Following Taiwan's Transportation Occurrence Investigation Act and the Casualty Investigation Code of the International Maritime Organization, the TTSB is an independent transportation occurrence investigation agency responsible for conducting this investigation. The investigation team also included members from the Maritime and Port Bureau, Ministry of Transportation and Communications; the Evergreen Marine Corp. (Taiwan) Ltd. and the Myanmar Maritime Administration.

Based on a comprehensive analysis of the factual information, the investigation identified 8 findings and issued 3 safety recommendations. The final report was reviewed and approved at the 83rd TTSB Board Meeting held on February 13, 2026.

Ⅰ. Findings from the investigation

Findings related to probable causes:

1. During the outbound turning maneuver in the restricted waters of the Yangon River anchorage, Uni-Active was operated astern without personnel assigned to monitor the stern movement. The pilot and the master focused primarily on the distance between the bow and the riverbank, while the bridge team did not effectively integrate radar and other navigational monitoring information to maintain overall situational awareness of the vessel’s movement. As a result, the increasing sternway inertia was not identified in a timely manner, and the vessel’s stern collided with small vessels moored alongside the berth at a speed of approximately 3.3 knots astern, resulting in the sinking of two vessels and damage to a third vessel.

Findings related to risks:

1. Prior to commencing the turning maneuver, the pilot and the master did not conduct a sufficient Master–Pilot Information Exchange (MPX) in accordance with the recommendations of IMO A.960(23). No agreed turning plan or shared understanding was established regarding maneuver intentions, such as speed control and clearance distances, nor were contingency actions discussed. This limited the bridge team’s ability to take timely control in response to emerging risks.
2. Although the master became aware that the pilot’s selected turning method in the restricted waters differed from previous practice, the associated risks related to vessel speed, position, and passing distances during the turning maneuver were not discussed with the pilot. In addition, the bridge team did not establish clear monitoring priorities or task allocation to support effective risk oversight during the operation.
3. During the operation of weighing anchor and conducting a turning maneuver in restricted waters, the vessel did not treat the risk of stern movement astern as a primary monitoring focus. Throughout the operation, no real-time identification and response measures were established based on changes in vessel speed, position, or the relative distance of the stern. As a result, this risk was not timely identified or addressed in operational decision-making, thereby increasing the risk of collision during turning operations within the river channel.

Other findings:

1. Steering gear and main engine were operating normally at the time of the occurrence.
2. At the time of the occurrence, the vessel’s Global Positioning System (GPS), Automatic Identification System (AIS), and Electronic Chart Display and Information System (ECDIS) experienced brief signal instability, which was a commonly reported condition in this river section.
3. At the time of the occurrence, weather conditions were good, with a south-easterly wind at Beaufort scale force 2 and good visibility.
4. The master and on-watch crew of the vessel held valid certificates of competency issued by the competent authority of Taiwan. The pilot held a valid pilot licence issued by the competent maritime authority of Myanmar. No evidence of fatigue was identified.

Ⅱ. Transportation Safety Recommendations

To the Evergreen Marine Corp. (Taiwan) Ltd.

1. Review and strengthen the risk identification and management practices for vessel operations involving weighing anchor and turning in restricted waters or anchorages, as appropriate. Relevant procedures or operational guidelines should appropriately highlight key risks such as stern movement astern during such operations, and guide masters to incorporate these risks into primary monitoring and decision-making considerations both prior to and during the operation.
2. Strengthen fleet training related to the Master–Pilot Information Exchange (MPX) and bridge monitoring, enabling masters to fully discuss turning plans, tug utilization, tidal conditions, and contingency measures with pilots prior to pilotage. Training should also emphasize the importance of maintaining effective communication and monitoring during operations, and of providing timely reminders or intervention when abnormalities are identified.

To the Myanmar Maritime Administration

1. In line with the recommendations of the International Maritime Organization (IMO) Resolution A.960(23), strengthen pilots’ pre-pilotage Master–Pilot Information Exchange (MPX) procedures, including discussion of turning plans, tug utilization, tidal conditions, and contingency measures. This will assist the master and pilot in establishing a shared understanding of shiphandling intentions and enhance operational safety in restricted waters.

The complete final report (available only in Chinese) can be downloaded at

https://www.ttsb.gov.tw

Ya-Ting Chang, Director

Secretariat Office

Tel: +886-2-7727-6210

E-mail: yating@ttsb.gov.tw

Willis CHEN, Senior Investigator

Marine Occurrence Investigation Division

Tel: +886-2-7727-6246

E-mail: willis@ttsb.gov.tw