BSU: Interim report on the grounding of an LNG tanker

The Federal Bureau of Maritime Casualty Investigation (BSU) has published an interim investigation report regarding an incident where an LNG tanker run aground at the entrance to the Port of Mukran on 22 May 2025.

The incident

Before the vessel approached Mukran on 22 May 2025, the Master came on the bridge at 0305. At that time, the vessel was approximately 20 minutes from the Arkona buoy, and the bridge was manned by the Second Officer and the 0–4 watchman. There were no concerns regarding the surrounding maritime traffic, and the Master went back down for a few minutes to work on his laptop. At 0329, the Master returned to the bridge and spoke to the officer of the watch (OOW) about the pilot boarding time, the arrival speed, as well as the stand-by time for the mooring stations and the pilot boarding arrangement.

At 0335, the OOW called the pilot:

OOW: “Yes, sir, good morning, this is the vessel. ETA to pilot station 0500 at buoy MU 2, is that correct?”

Pilot: “0500 pilotage, yes, confirmed.”

OOW: “Yes sir, can you please confirm on which side pilot ladder to prepare?”

Pilot: “We have westerly winds, so keep pilot ladder portside, 2 m above.”

OOW: “Copy that, we will prepare portside. We will be preparing combination with pilot ladder 2 m above the water.”

Pilot: “Yes, that’s fine.”

This exchange prompted a discussion between the Master and OOW regarding which side the pilot would board on. The Master seemed puzzled, as in his view, with westerly winds, the starboard side would be the leeward side. Based on an email from the agent and the supposed confirmation from the pilot, he assumed that the pilot boarding place was at buoy MU 2 and not at the charted position.

The bridge team discussed the pilot transfer position and reviewed the chart information in front of the harbour entrance. At 0343, the vessel received a call from VTS. In addition to requesting various vessel details, they also asked whether this was their first call to Mukran, which was confirmed.

From 0352, the watch change to the 4–8 watch took place. The OOW informed his reliever that the pilot’s boarding position was at buoy MU 2. The new OOW, a Third Officer, contacted the Boatswain, who reported that the pilot ladder could only be prepared on the starboard side due to mooring lines already being in place. The Master informed the pilot accordingly at 0403. There were no objections from the pilot station, which called back just one minute later to report that the pilots might be delayed by about ten minutes.

At 0405, the Master took over the conning, switched the helm to manual control and began issuing orders to the helmsman. In addition, he began to slowly reduce the ship’s speed in consultation with the engine control room. The speed over ground was still 17.8 kts.

At 0414, the vessel passed the reporting line at the harbour approach. VTS requested a report to port control on CH 15. The person in charge there informed the vessel that, due to strong wind, it was unclear whether the vessel could enter the port. This would be decided by the pilots once they boarded. The Master also received confirmation that the approach could continue for the time being.

At 0428, the Master called on the bridge team to actively participate and emphasised that any safety-related observations should be raised. Two minutes later, he stated that he assumed the approach might be cancelled due to increasing wind. At that time, the wind was 25–29 kts (6–7 Bft) from a westerly direction.

At 0436, the Master confirmed with the engine room that the engine telegraph could be used freely, and set it to “Half Ahead” and shortly afterwards to “Slow Ahead” (SOG 11.5 kts). A few minutes later, the vessel reported to VTS that it was four nautical miles from the harbour entrance.

At 0442, the vessel passed the charted pilot transfer position at around 9 kts SOG. Shortly afterwards, the Third Officer observed vessel movements in the harbour area and speculated whether one might be the pilot boat. A tug left the harbour entrance and headed towards the vessel, reporting this via VHF to port control.

At 0450, ten minutes before the scheduled pilot boarding time, the Master asked for the Chief Officer to be called to the bridge. One minute later, he set “Full Ahead” (SOG 7.7 kts). Further tugs were observed departing the harbour and reporting to port control. The Master ordered the forward and aft mooring stations to stand by.

At 0453, speed was reduced to “Half Ahead” and the bow thruster was started (SOG 8.6 kts). At 0455, the Chief Officer arrived on the bridge. By 0458, four tugs had left the port and were en route to the vessel.

At 0500, the Master altered course slightly to port in order to adjust the approach angle to the fairway. The Third Officer left the bridge to meet the pilot and later take charge of the aft mooring station.

At 0504, the Chief Officer drew attention to the vessel’s speed of 8.9 kts. The Master did not alter the engine setting. The vessel was still 0.5 nm from the fairway entrance. Wind was 16–27 kts (5–6 Bft) from westerly direction.

At 0506, a tug contacted the vessel and queried whether a pilot was on board. This was denied, and the tug advised that speed must be reduced immediately. The Chief Officer confirmed that speed was being reduced. The engine was set to “Slow Ahead” (SOG 8.9 kts).

A pilot boat was then dispatched from the port and made its way towards the vessel at full speed. The pilot established contact and instructed the Master to abort entry and not proceed without a pilot. The Master acknowledged and ordered a starboard turn.

The vessel attempted to manoeuvre within the fairway but was already positioned too far off track. A corrective turn was initiated, but the turning radius was insufficient to remain safely within the channel. At 0509, the Master informed the pilot that he would not enter the port. The pilot advised that stopping conditions were uncertain under prevailing wind conditions.

At 0512, the vessel passed a buoy pair centrally and set the engine to “Stop”, then “Very Slow Astern”.

Shortly after, the pilot advised that there was sufficient water on the starboard side and instructed the vessel to proceed slowly while monitoring buoys. The Master attempted to regain alignment but the vessel continued to deviate.

At 0514, the pilot instructed that tug assistance be used fore and aft and that the vessel proceed cautiously towards the breakwater. Tug connections were established.

At 0516, the engine was set to “Half Astern” and then “Full Astern”. The vessel continued to drift under wind influence from the port bow.

At 0517:37, “Crash Astern” was ordered. Tug connections were being finalised fore and aft. Despite full astern power, the vessel’s speed dropped rapidly. Between 0518 and 0519, speed reduced to zero and the vessel grounded on the port side of the fairway with the forward section, coming to rest and making slight contact with a navigation buoy, with no reported damage.

source : safety4sea