Top Spreaders

This is a 2 year old boat and I do not believe that the break came from transporting as it would not have been assembled.  What is evident that I can see on the port one is the fit of the Stem ball support is very tight and the wedge effect with forward load would be magnified.  It is a very long spreader and we did get in a 40knot plus gust on port tack with full main up during a race and broke our carbon spinnaker pole while goose-winging and trying to release the sheets which were caught in the parrot beak.   On the port spreader photo you can see the aluminium stress at the point of break.  Perhaps it is enough to break it, perhaps not.  Once broken, then a halyard could then get caught behind the inner edge.  As I am an engineer I have access to FEA and solid modelling so I will have a bit of a play with leverage.  I would guess at the spreader length being about 1100-1200 long and the pin/pivot point to the fracture is only about 50 mm so that is a force multiplier of about 24 times. 

Wow! Thanks for sending the pictures, although I'm not quite seeing it in the port spreader, but take your word for it.

Antsy wrote: Matt1, There has been no collision, no rafting up, it stays in a marina.  It could only have happened during sailing and there is a possibility of fracturing first and then subsequent movement.  Without a metallurgist examining it I am not able to conclude a single episode break or from fatigue.  The point is that if the clearance around the lower Stay hole reinforcing were larger then any forward force on the outer point of the spreader would have resulted in compression where the inner point of the broken piece would stop against the mast pad creating a different force diagram rather than wedging at the broken point causing tensile stress.  This could be a case of manufacturing tolerances causing an isolated incident.  The point of posting this on MyHanse is for me to find out if there are other incidents and to alert other owners of a possible area which should be checked at least annually.  As there is no complete break the strut is still in compression and the outer stay still supporting the mast.

Hi we had the same failure 2 years ago on our 2014 415 . Our rigger sourced 2 new top spreader arms from Seldon . Our rig was set up quite loose and is now much tighter , the leeward lower shroud was quite loose before when sailing , this is no longer the case   . I believe the failure was this looseness this allows the mast to flex forward when you are pounding into the waves , the mast pumps forward and back and that is what cause the Aluminum to peel away. Its definitely something to watch for