Two rigging failures - could they be connected?

Danny Jo

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Sailing from Tobermory to Rhum the week before last, we waved fairwell off Ardnamurchan to the lovely Namaste (see first picture - she had beaten Freestyle, but only just, in the long beat up the sound of Mull the day before). We were close hauled on the starboard tack. The north-westerly wind had increased to about 15 knots true when I heard a bang. To my crew at the chart table, the bang seemed to shake the hull. He came up, and we saw that the starboard aft lower stay was swinging in the breeze. Unlike the other stays, it had been fastened to the chainplate by a shackle pin, the loop of the which shackle provided an attachment point for the running backstays when not in use. Remarkably, both the shackle and its pin were still on the deck, albeit looking a bit worse for wear. After getting hold of the swinging stay (and not a little prevarication), we hove to on the port tack, found another shackle and refastened the stay, putting in precisely the same number of turns of the bottlescrew as we had taken out. We reefed the main, put a few rolls in the genoa, and enjoyed a cracking sail towards the sound of Rhum as the wind backed to westerly and strengthened. The second photo was taken at this time shows that Freestyle's top speed topped 8 knots (the GPS reading is averaged over 4 or 5 minutes). At this point there was another bang, the cause of which we did not locate until we reached our anchorage. The starboard lower spreader (edit - the whisky must have got to me - it's the starboard upper spreader, as any fule can see) had become detached from the mast - see third photo. On inspection we found that the casting on which the spreader is located (the casting is welded to the mast) had fractured through the hole for the spreader retaining bolt.

Common sense would suggest that there must be some connection between these two events. Pressure on the opposiste spreader by the genoa while hove to? A forward bending shock on the mast at the spreader when the aft lower stay (which is attached to the mast at the root of the spreader - edit: the root of the lower spreader, which was undamaged) parted? Neither of these explanations seems sufficient to me.

Any other suggestions? (And was I, as my crew suggested, rather cheeky to suggest to Namaste's skipper that she might like to tighten her main halyard for the camera?)

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Danny Jo

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I promised to send Frances the photos, but I've left her email address 350 miles away. Frances, if you read this, send me a PM with your address please. And apologies for the cheap crack - Namaste makes Freestyle appear positively scruffy.
 

ytd

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If spreaders are not fastened to the outer stay and there is any play in the spreader to base fixing, they can slip down so they are no longer bisecting the outer stay. Eventualy the downward force on the spreader becomes too great and it breaks. On older boats I often have to push the spreaders up a few cms and put a bit of tape or small nose clamp underneath the spreader to hold it in the correct position. Maybe when your lower broke the spreader dropped down and the resulting force broke it.
 

lw395

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Loss of any stay is a pretty big problem. It does not seem unreasonable that the loss of the lower allowed the mast to bend in a way that stressed the upper spreader. There may not have been much margin there, there could have been a casting fault etc. Equally, the two events could have had a common cause, poor rigging or assembly, as the shackle should never have come undone. Shackles are generally frowned on in rigging, they at least need to be properly done up, moused, and checked periodically.
I'm not sure I would push my boat to 8knots after a rigging failure either. Winding on the same number of turns is not the same as checking the rig tension is in balance. Still, the mast stayed up, so damage was limited.
 
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