SPADE Anchor Safety WARNING

[diederik]

Your SPADE anchor may be unsafe.

Mechanical failure of a SPADE Anchor was found
by the Maritime Safety Authority of New Zealand to have directly caused the
loss of the yacht "Deep Blue".

Some simple modifications can make a Spade Anchor safe. Please warn your
fellow mariners who may own such an anchor. Instructions for anchor modification, and the Maritime Safety Authority report, in the URL below.

http://www.geocities.com/spade_anchor_test

The required modifications really are very simple, and critical for safe
boating.



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[webcraft]

I have a Spade anchor, and find this whole incident bizarre.

The bolt does not take any of the anchoring forces when the load is on the anchor - the shank is retained in the fluke by the socket so the whole shank is the lever, with no force on the bolt. Even if there was no nut on the bolt, it is hard to see how it would come out under tension - in fact, the anchor would still stay together under tension (ie when in use) if there was no bolt there. The bolt is no more a structural part of the anchor than the seizing wire used on the shackle on your anchor chain.

The only possibility therefore - and very unlikely in my opinion - is that the bolt came out while the anchor was being deployed or was on the way to the seabed. If this was the case then it should have been immediately obvious to the skipper of Deep Blue that the anchor was not set properly - unless he just threw the anchor overboard and took no other positive action to ensure that the vessel was anchored. If so, then the accident is no-one's fault but his own.

As for the assertion on Deep Blue's website that non-one would trust their rigging to a nyloc - well, for many years I flew microlights. These are highly certified and subject to stringent regulation, and many vital parts are secured using nylocs. The main thing to remember with these nuts is that they should not be used twice. It would be interesting to know if Mr. Meenken had disassembled and reassembled this anchor at any point and, if he had, whether or not he replaced the nyloc with a new one.

I have the deepest sympathy for the crew of Deep Blue, but I think there must be more to this than meets the eye - as is also suggested in the article you can read <font size=1><A target="_blank" HREF=http://www.bluemoment.com>http://www.bluemoment.com</font size=1>

 

[copterdoctor]

I agree with Nick, with the possible, again unlikely exception, that if for example in a swell the load was consistently going on and off the anchor.
As for Nyloc nuts, if you cannot trust them then do not go on an aircraft of any kind. Nylocs are used world wide in a host of demanding environments. (If fitting nylocs always ensure at least one complete thread is through the nylon).

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[bruce]

looked at my spade last week, no nyloc nut on it, just basic nut, so i think everybody should check to see if they have the nut that spade says should be there.

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[graham]

Bit of de javu ,Im sure Ive read this somewhere else??

I dont have a spade anchor but if I did I would eat my hat if a new properly tightened Nyloc nut came off on its own.

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[hylas]

From the designer

Sorry Bruce, but all SPADE anchors are sold with a Nylock nut..
But we can't control what hapen to the nut of all anchors after they have been delivered to the customer..

I will suggest that you change the nut you have for a Nylock nut..

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[Spicemariner]

We also have a Spade anchor and have been cruising for two years now. Anchor has never let us down. Held perfectly in 60kts for three hours one night.

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