3167 Benedictus NSM1 (ALN Boatyard) The inverted bolt (I assume?) behind the spinnaker shoot has just sheared off flush at deck level! Has anyone repaired / replaced this before, or am I looking at an insurance claim? It sheared shortly after I put on nominal rig tension with the highfield, fortunately the gate saved the mast going over. I cannot imagine drilling out a stainless bolt without a pillar drill and jig, then having to rout part of the underside of the shoot lip before epoxying in a replacement bolt and replacing the deck fitting. anyone got any advice or suggestions please...........

Can you not drill it out and re-fit a new bolt?

That's the point, stainless is very hard, assuming that you centre punch it, I doubt the ability to line drill by hand through the centre of a bolt that may be 38mm long without skewing off into the deck / shoot mouth - this could only be achieved some sort of pillar drill and jig. I am assuming it is an inverted bolt embedded possibly with a plate washer to spread the load..............further thoughts anyone?

Hi Martin,

Possibly an alternative (see link) use bow plate/swivel bolted or screwed through to underside of chute lip as per image. If using bolts maybe suggest that nuts are on the topside so that spinny does not snag. This will work and saves faffing about with single bolt arrangement as you describe. Have a feel around under the deck as I would have thought you could just punch the offending bolt through.

Thanks Richard the fitting on the link appears to be the same bolted swivel fitting as on mine and yes the nut was on the topside the two small screws retain a cover plate only. Assuming that the bolt does go right through then I think the head has been countersunk and then filled around so that there is no snagging of the spinnaker. Perhaps a builder or a restoration specialist may comment as to how this is normally achieved. Benedictus is in immaculate condition and I am somewhat loath to start punching the end of the bolt shank in case it splinters out into the shoot. I will put a small mirror in the shoot and see if I can see any evidence of a bolt or filler with a torch. - please keep any suggestions coming.

I konw exactly the fitting you mean as I used to have the same on older merlins I once owned.Very difficult to remove from memory, but then I am stating the bleed'in obvious hence your question! I don't believe that sort of arrangement is used anymore. The fitting in the link is the chap you need/could use or source the same as in the earlier picture of Rob Holdroyd's boat. I suspect Laurie just screwed the plate on as that would surfice. It's how you make good the hole that's is already there possible epoxy in a down if you can drill out enough steel. Unfortunately your sort of arrangement was designed and installed to rarely be removed!!! If you have a digi camera stick it under the deck and take a picture, the flash will light up what you want to see much better than a mirror

Oh dear, I've got one of those too....hasn't sheared off yet thankfully.

I suggest a mirror poked down the chute hole (and maybe a lamp from inside the boat) to examine, whilst you scratch away the varnish a bit, to expose any filler.

Scratches here won't show, and you can touch up the varnish without too much worry.

Remove what you have and leave the bolt old bolt in situ. Get the more modern swivel now used and fit (bolt)to the bow. The new swivel fitting should cover the original screw holes and cover the centre bolt.
Benefit this type of swivel does not undo when you roll the jib.

Result - did the trick with the digi camera as you suggested Richard and it revealed a neat square of filler - so took the bull by the horns and tapped the bolt shank with a punch - out came the filler followed by the rest of the 50x5mm bolt. I intend replace the bolt with a new 6 or 7mm item hopefully to stop a re-occurence. Thanks to everyone for ideas and comments. I think 3167 Benedictus is eligible for vintage events next year so I will try and attend one or two. Any suggestions, I am based at Southport Sailing Club on Merseyside ?

Why not come down to Hollingworth for our Open Meeting. We welcome all ages of boat, and there will be plenty of people who will give you hints and tips.

If replaceing with the same sort of bolt, perhaps a "lock nut" arrangement (2 nuts tightened against each other) would hold the swivel, allowing it to turn without risking undoing the nut?

Yes Mags - probably use a stainless nyloc nut just backed off a fraction.

Is that bolt failure at all common? If so, a precautionary replacement might be useful for 2988(also Aln), and might possibly save us a mast. I haven't forgotten losing the latter on 1620 with a shroud fitting failure, when its companion was impossible to dislodge even with fairly extreme mechanical force in my workshop.

Yes not uncommon for the bolt to break used to replace the bolt every 2-3 years particularly if you also used the bow fitting to fasten the boat when towing on the trailer. 

Better to fit the RWO swivel base