Swinging mooring - an easier solution

TopBanana

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I used to have a central forward cleat which made using my swinging mooring very easy. I'd run the strop over the bow roller and hook right on. I had to remove that cleat in order to install a windlass, so I now have port and starboard forward cleats. That works very well in marinas, but on the swinging mooring I found the Y bridle rather fiddly and I had chafe issues last season because the narrow fairleads didn't allow tubing to fit through. Upgrading the fairleads was the initial plan but that looks difficult due to access.

I've had an idea this year that I might be able to install an eye bolt between the bow roller and windlass. It would run through the deck and I could secure it into a large stainless backing plate. That would allow me to run chain from the mooring, over the bow roller once again, and secure using shackles at both ends. (I'd use a mooring compensator or something similar to reduce snatch)

Does this sound sensible? Are eye plates / bolts designed to take horizontal loads? What sort of load rating should I look for given my displacement of 4500kg and fairly high windage?
 
I would consult an expert before relying on a single bolt. In my understanding, eyebolts are designed to deal with direct loads in line with the shank of the bolt. A 90 degree loading requires a generous shoulder to the eye and a reduction in the SWL to 25% of that quoted for a straight lift. In addition to reinforcement below the deck, you may also require a wide washer or plate to ensure that the shoulder does not crush the underlying deck from above when it comes under horizontal load. Depending on the area of your boat, a gust of wind on the beam in a storm may generate more than a tonne of force. In my non-expert opinion, this would require a fitting with a minimum breaking load of 4 tonnes to allow for a reasonable safety factor. You would need to be sure that the deck could deal with such loads, an eyeplate may be a better idea as the load can be distributed across a wider area with 4 or 6 bolts, provided that the welding is sound!
 
In my experience, chain will jerk and snatch unless the strop is so short that it never goes slack.
I'd be cautious about relying on one bolt in a bending stress.
I fitted a big cleat right close to the bow roller. 4 bolts and backing plate out to the toe rails.
Maybe you can do similar, if the line of pull to the windlass clears the cleat?
Maybe get something 'low profile' made? Cleat or bollard?
At least, a monsta 4 bolt pad eye, not an eye bolt. IMHO!

One of these on steroids?
Folding pad eye - Dia 10 mm | Wichard Marine

Chafe is the enemy, you have to do what it takes to eliminate it.
 
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