Implications Arising For Owners following NSW Coronial Inquest into the Deaths Aboard the Yacht Rising Farrster
The NSW Coroner has recently completed his Inquest into the deaths of two (of the six) members of the crew of the yacht Rising Farrster, a Farr 38 owned by a UK based organisation, and built in 1993.
The Coroner found that both deaths occurred as a result of drowning when the keel of the yacht separated from the hull causing the vessel to capsize.
The Coroner has recommended that a précis of his summing up, findings and recommendations be distributed to owners of light displacement yachts fitted with fin keels built subject to pre 1994 ABS approval. His Worship made this recommendation so that appropriate decisions can be made by owners as to checking and/or modification of yachts.
Rising Farrster was on a sail training passage from Southport, Queensland, to Sydney, NSW after having previously made the passage from Sydney to Southport, when she capsized off Evans Head. The wind was about 20 knots with a 1.5 metre swell.
The cause of the capsize was established to be that the fin keel separated from the hull unexpectedly. Within 15 to 20 seconds the yacht had capsized. The Coroner established that the yacht did not founder on a reef. Two of the crew died when they were unable to make their way out of the yacht's cabin.
The Coroner investigated the causal factors of the capsize and subsequent actions. In arriving at his recommendation to advise owners of light displacement yachts fitted with fin keels built subject to pre 1994 ABS approval he investigated the design and building of Rising Farrster and her requirement to be built to survey.
The Coroner concluded that Rising Farrster was not required to be built to survey standards as she was originally contracted to be built as private yacht, and in her subsequent role as a sail training vessel she was only required to be the subject of a "visual inspection".
After considering apparent anomalies in the various legislation affecting sail training vessels the Coroner recommended that the relevant statutory authorities revise their respective legislation regarding exemptions of offshore sail training vessels from more rigorous requirements.
The Coroner also concluded, by agreement with technical experts' statements, that:
· The primary cause of the failure was inadequate hull shell thickness in way of the keel washer plates.
The 1986 revision of the ABS guide does not properly account for the shear loads at the edge of the washer plates in the case of Rising Farrster. In fact the 1986 ABS required minimum hull shell thickness of 6.8 mm is only 37% of the 18.5 mm of thickness required to produce a safety factor of 2 on shear stress in way of the washer plates.
· The agreed to as built shell thickness of 5.5 mm is 1.3 mm thinner than the ABS approved laminate of 6.8 mm, or 30% of the 18.5 mm of thickness required to produce a safety factor of 2 on shear stress in way of the washer plates.
· The 1996 (sic 1994?) version of the ABS guide does not properly account for the shear loads of the washer plates in the case of Rising Farrster. To comply with the later revision, the hull shell laminate in way of the washer plates would have been required to be a minimum thickness of 27 mm.
Agreement was reached by the technical experts on shear stresses that could be withstood by the as built laminate, however there were differences of opinion as to the shear stresses that the structure would be subjected to in actual conditions. Various modelling, however, only reached a Safety Factor of a maximum of 1.5, which is substantially lower than the 2.857 suggested by the 1994 ABS rule, and still lower than a professional opinion that an acceptable Safety Factor prior to 1994 would be no less than two.
In conclusion, the Coroner found that "The expert evidence is, however, that there was a combination of design, build and ABS requirements that resulted in the hull shell being inadequate for this type of keel. This is of concern to me, assuming there are other yachts constructed and designed similarly. Accordingly, I propose to make a Recommendation pursuant to Section 22A, Coroners Act 1980".
His Worship's relevant recommendation is "The Australian Yachting Federation (now known as Yachting Australia), in conjunction with the Yachting Association of NSW, and yacht clubs endeavour to contact owners of light displacement yachts fitted with fin keels subject to pre 1994 ABS approval, to provide them with a précis of my summing up, findings and recommendations at inquest in order that appropriate decisions can be made by owners as to checking and/or modification of yachts."
This release issued by Yachting Australia as recommended by the Coroner is a summary of the Coronial Report. Neither ISAF nor Yachting Australia make any comment or draw any conclusions or inferences save those made by the Coroner.
For further details please contact Colin Chidgey, Competition Manager, Yachting Australia, +61 2 9902 2155, firstname.lastname@example.org