Hull Failure
Hull Failure
Hull structures are designed to strengthen the hull of a keel boat to support the keel. These structures should support the keel for the life of the vessel outside abnormal circumstances including groundings. Various systems for supporting the keel within the hull structure exist, governed in Europe and the USA, by compulsory construction standards, with no compulsory standards in Australia. See Construction . These standards struggle to keep up with new race designs and the use of exotic materials. Further Reading
Failures often begin with corroded keel bolts, cracked welds, or delaminated fiberglass around the keel sump. These weaknesses may result from poor design, age, or unreported groundings. Once the attachment fails, the hull structure itself can tear apart, leading to large breaches and rapid flooding. Internal supports such as bulkheads or stringers may also separate, worsening the damage.
Underlying causes include inadequate engineering, poor-quality construction, and limited inspection access to critical components. Many yachts have hidden or encapsulated keel bolts, making corrosion difficult to detect. In some cases, repairs after groundings are cosmetic rather than structural, leaving unseen weaknesses.
Investigations into keel failures often highlight gaps in regulation and the lack of mandatory inspection standards. Reports from maritime authorities typically recommend improvements but carry no enforcement power.
Terminology
Common Causes of Hull Structure Failure
Signs of Potential Failure Checklist
Further Reading
Hull Failure
ISO 12215-9 Regulatory developments in structural keel design. 8th High performance yacht design conference. 2024.
Ground Damage Julian Smith, Hambly Marine Surveyors
Wavetrain CHEEKI RAFIKI: Hull Found Again.2014.
A study of a keel failure and the loss of the Cheeki Rafiki International Institute of Marine Surveyors
MAIB Report
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Disclaimer
At RWS Sailing Safe we do not pretend to know everything. We are not your naval architects, marine engineers, or part of the sailing elite.
We’re just everyday sailors — the kind who grew up racing dinghies, sanding and varnishing boats, cooking sausages after club races, towing trailers full of boats to championships and regattas. Some of us moved on to keelboats, crewing offshore, racing up and down the Queensland coast, and even taking part in major races like the Sydney to Hobart. We share information based on our experiences and research, but we are not professionals. We cannot be held accountable for the other sites the articles link to. That’s their site. We have tried not to plagiarise anything, just link to the available articles. We have used all our own photos and that copyright stays with us. We are trying to gather all the research and articles and present it in one place for others, as a resource.
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