Ten crew members are missing after a cargo ship carrying more than 4,000 tonnes of steel sank following a nighttime collision with a tanker in the Sea of Marmara, south of Istanbul.
The Turkish Directorate General of Maritime Affairs said that the cargo vessel Tugberk Imamoglu failed to respond to emergency calls after colliding with the chemical and oil tanker Alsu in the early hours of the morning.
Search and rescue operations were launched immediately after an emergency distress signal was picked up at 03:26 local time. The alert was transmitted by the vessel's Emergency Position Indicating Radio Beacon through the satellite-assisted COSPAS-SARSAT search system.
Rescuers located an empty lifeboat floating in the water shortly after arriving at the scene. Maritime authorities said that repeated attempts by the Search and Rescue Operations Coordination Center to contact the ten crew members on their mobile phones received no response, leading officials to conclude that the freighter had sunk.
Search operations launched off Silivri
Fourteen search teams, a helicopter and a second vessel are currently participating in the rescue mission, according to local authorities. The collision occurred at 03:15 local time, approximately 18 nautical miles south of Silivri, a coastal district located west of Istanbul along the northern shore of the Sea of Marmara.
The Sea of Marmara is an inland sea situated entirely within Turkey, serving as a critical waterway connecting the Black Sea to the Aegean Sea through the Bosphorus and Dardanelles straits. It is one of the busiest maritime trade corridors in the region, carrying heavy commercial shipping traffic between eastern Europe, the Mediterranean and Asia.
Authorities confirmed that the collision took place within a designated traffic separation scheme off Silivri. Traffic separation schemes are maritime routing systems designed to regulate ship movements in narrow or congested waters, separating opposing flows of vessel traffic into designated sea lanes to reduce the risk of collisions.
Steel cargo bound for Black Sea port
The Tugberk Imamoglu was carrying 4,199 tonnes of rolled steel at the time of the collision. The vessel was travelling from Iskenderun, a major industrial port city in southern Turkey's Hatay Province, to Karadeniz Eregli, a prominent steel-manufacturing port city located in Zonguldak Province on the Black Sea coast.
According to the Istanbul governor's office, an inspection of the second vessel, the chemical and oil tanker Alsu, revealed no visible damage. The tanker remained operational following the incident as search operations focused on locating the crew of the sunken cargo ship.
Iskenderun and Karadeniz Eregli are major industrial hubs in Turkey's steel industry. Merchant vessels transporting heavy industrial goods frequently navigate the Sea of Marmara when travelling between ports on the Mediterranean coast and industrial destinations along the Black Sea.
Satellite distress system triggered
The emergency signal from the Tugberk Imamoglu was registered by the COSPAS-SARSAT system, an international satellite-based search and rescue network that detects distress beacons emitted by ships and aircraft. The system relays location coordinates directly to national emergency coordination centers to enable rapid response efforts.
An Emergency Position Indicating Radio Beacon, or EPIRB, is a portable radio transmitter mounted on commercial vessels. When a vessel sinks or capsizes, the device is designed to deploy automatically or manually, broadcasting radio signals to satellite constellations to pinpoint the exact geographical position of the emergency.
Turkish maritime authorities said that search and rescue operations remain in full progress, with emergency teams continuing to search the waters south of Istanbul for the ten missing crew members.
