Kategorie: News
What happened?
On 25 April 2023, the liveaboard boat M/Y Carlton Queen, built in 2022, capsized shortly after the start of a liveaboard cruise on its way from Abu Nuhas across the Strait of Gubal. Winds were blowing from the northwest at a speed of 30km/h and the air temperature was 26°C. The M/Y Carlton Queen has a length of 42m and a beam of 8.5m and is designed for 28 guests in 14 cabins. At the time of the accident, 26 guests and 9 crew members were on board. The safari guests were mainly experienced diving instructors. All persons could be picked up by ships in the vicinity. According to the shipping company, the M/Y Carlton Queen sank as a result of the capsize.
Article by Jan-Philipp Lauer, MSc
According to eyewitnesses, the ship was already listing slightly to starboard when the liveaboard started. At the time of the accident, almost all the guests were inside the ship after a previous dive. According to eyewitnesses, the ship continued to heel to starboard at this point, as if in slow motion, until it came to rest on the starboard side and did not right itself again. All the guests were able to leave the interior of the ship. Some of the guests suffered minor injuries.
Why does a ship capsize?
A ship either floats on an even keel, i.e. the keel is parallel to the water surface, or it has an attitude. If a ship is listing, it is either listing (leaning) to starboard or port. This can be independent of the wind or the ship leans (heels) under wind pressure to the leeward side (the side facing away from the wind), whereby the windward side (the side facing the wind) lifts. Curving leads to heeling in the opposite direction to the direction of the curve in larger ships. Another possibility is that the trim is not equally weighted, resulting in head-heavy (dipping deeper towards the bow) or stern-heavy (towards the stern) trim. When a ship is on an even keel, it can move smoothly and straight through the water.
However, if a ship is list, this means uneven weight distribution - then a ship is trim. Large ships have ballast tanks to be able to establish a correct trim at all times. Small and medium-sized vessels must achieve the correct trim through correct equipment and loading. Correct trim must first be ensured when building a ship. When operating a ship, it is a fundamental task of the ship's command to ensure correct trim, as this has a significant influence on the stability of a ship.
Stability is the ability of a ship to maintain an upright floating position or to right itself from a heeled (inclined) position. The basic parameters of ship stability are centre of gravity and centre of buoyancy. The centre of gravity describes the imaginary point at which the weight of the ship is applied in the direction of the centre of the earth. During heeling, this point retains its position in the ship, provided there is no change/displacement of mass, e.g. due to water ingress or the tearing loose of heavy equipment.
The centre of buoyancy is the imaginary point of application of all buoyancy forces resulting from the upward weight force of the water displaced by the vessel. When heeling, the position of the centre of buoyancy changes because the shape of the hull, which is now in the water, also changes the shape of the displaced water.
In an upright swimming position, the centre of gravity is directly below the centre of buoyancy. When heeling, this is no longer the case. The heeling causes the centre of buoyancy to move out in the direction of the heeling. A lever arm is created between the centre of gravity and the centre of buoyancy, which generates a righting torque. Due to the increasing lever arm with increasing heel, the righting torque continues to increase up to a turnaround point. When the turnover point is reached, a boat can no longer right itself but remains on its side, capsizes (turns) or continues to float keel-up (negative stability). This depends on the design. Because of the great impact of stability on ship safety, there are a number of regulations that must be observed both in the construction and operation of ships.
Classification
The listlessness, which according to witnesses was already present at the start of the safari, must be viewed critically, as this has a massive impact on the ship's stability. Even at sea, it would have been possible to correct the trim or abort the safari by stowing heavy objects if the stowage did not lead to a correct trim. Whether the ship's command made a stability assessment and why they did not ensure correct trim or abort the safari must be clarified.
Furthermore, it has to be clarified which changes of condition occurred that ultimately led to the capsizing of the vessel. At the present time, there is no evidence of a shift in weight, e.g. due to an engine breaking free from its foundation. There is also no information about a collision or water ingress. Nothing was reported about attempts by the crew to save the ship.
It needs to be clarified whether an abandon ship drill took place. It must also be clarified whether the command to abandon ship was given in a timely and proper manner and whether the signal used was sufficiently known to the guests. The suitability, absence of obstacles and marking of the escape routes and emergency exits must also be checked. Whether the crew carried out the evacuation properly and checked that all guests and crew members were present at the assembly point requires further clarification. The fact that many guests remained on the hull of the ship indicates a disorderly evacuation.
The reports of one defective liferaft (out of two) are worrying. Normally liferafts continue to function for years after missed maintenance intervals. As this ship was only built in 2022, this life raft should have been functional. Life rafts for 25 people are often used on safari boats of this size. Even with the intended number of people, the space on a liferaft is very cramped. With 35 people on board, the failure of one of the two liferafts posed a major problem.
Another point to be clarified is why the rubber dinghies carried were apparently not used as a means of rescue, especially as one of the two life rafts was not available. Neither lifejackets nor lifebuoys can be seen on the currently available photo and video material of the accident, which seems unusual in this situation.
The questions to be clarified require extensive clarification work within the framework of a maritime accident investigation by the Egyptian authorities. If this accident had occurred in darkness and without any other ships in the vicinity, it can be assumed that the outcome would have been significantly less favourable.
Update from May 4th, 2023:
We interviewed the three German divers and fellow travellers - Zoe, Dominic and Maik. Together with our accident expert Jan-Philipp Lauer, we discussed the situation in detail. See the picture for yourself. Some of the descriptions literally make your hair stand on end: Update and interview on the capsizing of the M/Y Carlton Queen