The ship left the berth without a real stability calculation. She fell over on the first turn.
On 3 January 2015 the car carrier Hoegh Osaka developed a heavy list on her first turn after leaving Southampton. The master and pilot ran her onto a sandbank on purpose to stop her capsizing. Nobody died; the ship lay on her side in the Solent for weeks.
Words in this case
- stability
- The ship's ability to return upright after heeling.
- centre of gravity
- The point where the ship's whole weight acts; higher means less stable.
- departure condition
- The calculated cargo, ballast and stability figures at the moment of sailing.
- cargo securing
- Lashings and stoppers that hold cargo against the ship's motion.
- to ground (a ship) deliberately
- To run her onto the bottom on purpose to stop her sinking or capsizing.
More words like these in the glossary and in listening practice.
What happened
Hoegh Osaka loaded cars, trucks and heavy machinery in Southampton. The loading was planned ashore and the ship's stability was worked out from the plan, not from what was actually loaded: the cargo was heavier and stowed higher than the figures said, and the ballast was not where the calculation assumed.
A few minutes after leaving the berth, in the turn at the Bramble Bank, the ship heeled over to more than 40 degrees and did not come back. Cargo broke loose and shifted, making it worse. The pilot and master steered her onto the bank, where she grounded and stayed upright enough not to capsize. The crew was taken off; a few were injured.
The Marine Accident Investigation Branch found that the ship had sailed without an accurate stability calculation, that the practice of "assuming" the condition was common on car carriers with tight port schedules, and that the ship had, in fact, been unstable when she left the berth.
Why it happened
- The departure stability condition was not calculated with the real cargo weights and ballast; the ship was unstable when she sailed.
- Cargo was heavier and stowed higher than declared, raising the centre of gravity.
- Cargo securing was not adequate for the heel that followed, so the shift made the list worse.
- Time pressure in port had made a quick estimate feel normal.
What to remember on board
- Before sailing, the chief officer has an actual stability calculation with actual cargo and ballast figures, and the master sees it.
- Declared cargo weights are checked against reality where you can: drafts, tank soundings, a look at what came on board.
- A ship that heels far and hangs there is telling you about her GM; the answer was needed before the turn, not after.
- Grounding on purpose saved this ship; know the water around your departure route.
What changed afterwards
The report pushed car carrier operators and ports to verify cargo weights and to give crews the time for a proper departure stability calculation; the ship was refloated and returned to service.
Three questions
The kind of questions a knowledge test asks about this case. Keys 1 to 4 answer, Enter goes on.
Read more
Source: Listing, flooding and grounding of the pure car and truck carrier Hoegh Osaka, Bramble Bank, Solent, Marine Accident Investigation Branch (UK), report 2016. Find the report.
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Plain-English summary of an official investigation report. Facts and findings are the investigators'; the wording is ours. Nothing here is legal advice or a substitute for the report itself.