[Public-List] Rigging....

Gordon Laco mainstay at csolve.net
Mon Jan 18 06:59:48 PST 2010


Hi Gang -

Suncor is not a manufacturer, but  distributor or fittings... and  
closed body, not a recommended type, are only one of many and mostly  
open bodied rigging screws they supply.

The triple cone (non insert)  style terminals they, Blue Wave and  
other companies supply are preferred industry standard in the  
construction crane industry since before World War One.

When my company was involved introducing them to the yachting crowd in  
Canada about eleven years ago, we had many old salts at the Toronto  
Show come up to the booth and tell us this 'new idea' would never  
work, or never be as 'good' as the cone idea.  Well that wasn't true.   
They are not a new idea at all, just a less familiar one to the non- 
commercial yachting consumer.

With regard to strength; there is nothing on a stock fibreglass boat  
that you can attach a 1/4 1x19 wire to that will withstand a fraction  
the load that the wire will stand.   Plus or minus some small  percent  
in a terminal makes no difference to the integrity of the rig.

What does make a difference is the longevity of the termination, that  
is most particularly, the confidence one would have in its still  
holding with the same security twenty or thirty years in the future.    
This is the one area where swages are not so good.   Swages can  
develop invisible cracks, and imperfectly straight swages can induce  
metal fatigue in your rigging wire by introducing a hard turn at the  
transition of the wire to the swage terminal itself.  Incidentally, it  
was the avoidance of that later peril that led people in earlier days  
to prefer nicro pressing over swaging.

I supply Norsemen, Stalock, Blue Wave, and Suncor terminals in  
addition to swages... Blue Wave and Suncor are identical, the only  
diff being that one comes from Denmark (more expensive) and the other  
from the States (less expensive).

The factory supplied Alberg 30 mast and its fittings may be considered  
to be massively overbuilt with regard to the loads our boat can  
deliver to them.   Yes, nicro pressed terminations are 'not so strong'  
as swages, but well done nicro presses (yes they are copper) still  
deliver more strength than any part of our fibreglass hulls can  
withstand.    The chain plates will pull out.    With regard to holes  
in the masts... yes, generally drilling holes in our mast can weaken  
them, but they are already so massive that you could honeycomb them  
before starting to create detectable weaknesses.  Don' worry about  
it.   Square holes, on the other hand, do tend to concentrate stress  
at the corners.  But who has square cornered holes in their masts?   
Drilled holes, once they are filled with hard tight fitting threaded  
machine screws can be considered as no longer being holes at all.    
(assuming there are not forty or so in close proximity)

Fractures in the treads of turnbuckles are caused by metal fatigue,  
which is caused by bad leads and vibration, not by load, although  
loading will exploit weakness.  Avoiding  1/2 the vibration time per  
year is the best reason I know to lower masts in the winter.

Gord #426 SURPRISE (just back from ten days at the Toronto Int'l  
Boatshow... hoarse from talking to people about doggy live vests, the  
advisability of multiple running lights ("I like the way nice patterns  
of greens and reds will look" says the friendly client, he was in  
earnest and I did my best to convince him that generally seeing four  
greens at night indicates to the other guy four boats...) and meeting  
many new and old friends.


 1263826788.0


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