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How to avoid expensive mistakes when you buy a new or second-hand yacht. 

Available on Amazon here

REVIEWS

Icom IC-M35We review the Icom IC-M35 handheld.  Read the full review here.

GMDSS A User's Handbook

By Denise Bréhaut

GMDSS A user's handbook

 

 

 

 

 

 

 


The Global Maritime Distress and Safety System (GMDSS) provides a fast and efficient way of calling for assistance at sea, whatever the size of craft or its geographical position. Since it was first published, this book has helped explain the system for anyone using GMDSS and has been excellent pre-course reading for students.

 

SAFASAIL CAP

SafaSail HatThe SafaSail Hard Hat looks just like a sailing cap, but will help protect you if you get a bang to the head.  See our review here

Letters: Weld issues in Vendee Globe

Reproduced from Scuttlebut Europe

From Kenny Robertson AMIMechE: With all the talk about failing keels recently, I remember my reaction mid summer this year, when Yachting life had pictures of a fabricated canting keel being manufactured. Absolute shock. Whoever designs these things needs to dig out BS 7608 or other related standards such as PD5500 Annex C [pressure vessels - my thing] for advice on faigue resistant design and fabrication.

Without getting too involved, the current advice is that all steels in a fabricated structure, no matter how 'strong' they are, or where the welds are, have pretty much the same fatigue life, and that fatigue life is related solely to how they are fabricated and inspected. The most fatigue resistant design is one where the welds can be fully inspected by NDT for external and internal flaws from both sides of the weld and have a smooth profile. The worst ones contain welds that cannot be fully inspected and have 'crack like' features.
Alas the pictures I saw fell into the latter catergory. The keel was full of fillet welds laid down by the MIG welding process. MIG welding is fine for many things and can be used easily by relatively unskilled personnel, but it is not used on critical things like pressure vessels for one simple reason. The weld is of relatively poor quality and does not penetrate far into the joint. As for fillet welds, they are triangular in section cannot be meaningfully inspected in anyway and always contain crack like features at the welds edges unless they are ground smooth afterwards and always a crack feature at the weld root. The designers of these keels need to specify full penetration, preferably double sided welds that can be properly inspected, using properly qualified and tested welders and welding procedures, using base materials that have been inspected for internal flaws and laminations - otherwise the keels will keep on falling off.
Making some huge assumptions and playing with some figures based on an imaginary keel I reckon the difference in fatigue life between the two models are: - full pen weld from both side, full NDT etc and smooth profile = 4860hrs; fillet welded construction = 34625hrs. That is a huge difference in working life. This ain't rocket science - it is common engineering pracitices and there is no need for these common failures.
 

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