Keel Faliure

[dougfrolich]

A very interesting report.

[Guillermo]

We were waiting for this report, Doug, thanks.
Keel failure has been extensively treated in these forums, as in:
Keels and Keels Again!
Should we discuss this there, rather than in the Open Discussion Forum?

I would like to highlight this from the report:

The Yacht Designers and Surveyors Association, Royal Yachting Association, Royal Ocean Racing Club, British Marine Federation, Royal Institution of Naval Architects, International Council of Marine Industry Associations and Institute of Marine Engineers and Science and Technology are recommended to:

M2007/173
Promulgate to their membership, owners, surveyors, and repairers/maintainers where appropriate, the following safety issues, which have been identified in this investigation report:
• The need to rigorously follow the standards selected for design criteria, especially where these include Safety Factors.
• The importance of referring to original and revised drawings when considering modifications to ensure that proposals will not compromise safety.
• The need for quality systems to be in place to properly check the product against the design criteria.
• The importance of examining keels for signs of fatigue cracking, especially where hollow fabricated steel keels are fitted, and to consider using non-destructive examination techniques whenever there is doubt about the integrity of the appendage.

M2007/174
Promulgate, where appropriate, the following comment at page 7 of the RSG Guidelines 2006:
• “RSG urges the industry and Notified Bodies to use EN Standards”.

[safewalrus]

I may not be a designer but in my humble opinion anybody who takes a 'glorified sailing dinghy' to sea in anything other than controlled conditions with adequate Safety cover is asking for problems.

According to the RCD this vessel was adequate for the conditions experienced, the problem was caused, as so often is these days by poor construction unkown to either the owner or the maintainance people! But in an age of building to refined tolerances such actions will continue to happen!

Your old built to withstand a hurricane vessel with over designed tolerances may not be as fast or as exciting but it will keep you alive! Whilst my heart goes out to the skipper and crew of this vessel, and anybody else who has lost people in these conditions building to fine tolerances will only cause more heartache and problems in the long run!

Well that's my view, it may not be popular but it is probably safe! Sorry if I've upset you Guillermo as a designer but as a seaman I believe you can see where I'm coming from!

[Guillermo]

Originally Posted by safewalrus

Sorry if I've upset you Guillermo as a designer but as a seaman I believe you can see where I'm coming from!

My heart beats with yours, Mike!

[safewalrus]

Cheers mate!

[Guillermo]

Some excerpts from the Synopsis:
...............
Hooligan V was the first of 10 yachts in a class developed by the Dutch yacht designer Maarten Voogd, for use in Recreational Craft Directive (RCD) Category B waters. The yacht was apparently designed following the American Bureau of Shipping (ABS) standards. It was built by Breehorn BV in Woudsend in The Netherlands and marketed by Max Fun Boats BV.
Unbeknown to the designer, the builder sub-contracted construction of the hollow keel to a steel fabricator who had no marine experience. The fabricator changed the design of the keel to ease manufacture and to reduce costs but without adequately assessing the stresses to which the keel would be subjected in service.
In 2005, the owner of Hooligan V contracted a UK yacht designer to optimise the yacht for IRM and IRC1 racing. This involved adding a further 160kg to the keel bulb.
At the end of a successful 2006 racing season, the yacht was delivered to Queen Anne’s Battery in Plymouth for repairs and maintenance. When the boat was taken out of the water, a considerable amount of detachment of the keel’s epoxy filler and anti-fouling was found. There was also evidence of the likelihood of fine cracking in the steel adjacent to the fillet weld, but this went undetected. At the end of January 2007, the boat was put back into the water for the delivery voyage from Plymouth to Southampton.
...................
Independent analysis of the “original” design calculations confirmed that they did not achieve the required Safety Factor. Further analysis of the keel design, as built, showed this failed to achieve the required safety factor by an even larger margin and that the subsequent addition of extra bulb weight in 2005 had exacerbated the situation. Hooligan V’s fabricated keel was unable to withstand the “in service” bending stresses and this led to the conditions of fatigue failure and consequent capsize of the boat.
Who Cares, a Dutch owned Max Fun 35 yacht had also suffered fracture of its keel, but in this case the cracking was noticed before the keel completely failed. The existence of this second case provided confirmatory evidence about the inadequacy of the keel design and construction.
As a result of the MAIB investigation, the Max Fun 35 yacht keel has been redesigned and now exceeds the minimum required safety factor. New keels have been fitted to 7 out of the 9 remaining boats.

[Mychael]

[QUOTE=safewalrus;160163! But in an age of building to refined tolerances such actions will continue to happen!


Is it that or is it building to a budget?

Mychael

[safewalrus]

same thing different excuse! If your building that way your building too big for safety

either way death is your companion - he ain't a nice guy, believe you me!

[MikeJohns]

Originally Posted by Guillermo

............
Keel failure has been extensively treated in these forums, as in:
Keels and Keels Again!
Should we discuss this there, rather than in the Open Discussion Forum?...........

Yes
Some good comments here, but this open forum doesn't report posts as the main ones do. I put my initial thoughts on the other thread (link above in Guillermo's post).