Eye bolts instead of eye plates for shrouds

[dac31]

Hi All,

I have a 19ft Prelude. The four shrouds are attached to the deck with two eye plates and penny washers.

I am in the process of rebedding and correctly backing everything attached to the deck. The problem I have is that the factory eye plates are bent inwards towards the mast, whether this is an original feature or from years of supporting the mast I am not sure. The eye plates are also mounted on the narrow flat surface of the deck fibreglass toe rail moulding.

Unfortunately, the toe rail moulding runs at an angle that means the shroud turnbuckles are pulling on the eye plate diagonally rather than as a chain load.

I am wondering whether a better fitment may be to replace the two eye plates with two eye bolts that can be swiveled towards the mast. The benefits being the removal of a potential weak point at the base of the eye plates where they are being pulled sideways.

The concern I have is whether the base of the eye plate will sit correctly on the deck, although this is not a compression load it is a departure from a flush deck mounting as the majority of eye bolts have a thin base at the top. I could of course fabricate a backing plate for both sides.

Any advice welcome. Unfortunately I cannot fit a swivel eye plate as the width of the toe rail allows a two hole mounting only.

Regards,
Dean.

 

[andsarkit]

Some U bolts are pre-bent like these:

A picture of your deck arrangement would help. I assume you want to change these:
for these
Either will have a reduced rating if not loaded in line. However for a small boat it would be quite practical to go up a size for more strength and use a toggle if you need more articulation. Try to find something with a stated working load and breaking load but the weak point is likely to be inadequate backing for the bolts.
Some eyebolts here: eyebolts
If the original fittings have lasted so far, I would be tempted to replace like for like and just improve the backing plates to spread the load.

 

[Refueler]

What about U bolts instead ? Maybe you can find U bolts that have same distance between the threaded parts ? So you put backing plate under / nuts etc.

My SR25 has these and they allow shrouds / stays to take up angle they need ......

You can see them along the toe-rail in this photo ...

I would not use Eye bolts ..... and not turned 90 deg as well ....

I would stick with plates in that case.

 

[penfold]

I scanned the prelude OA gallery and the ones that showed chainplate detail show U bolts; could you take a picture of your arrangements for clarity?

 

[Refueler]

I scanned the prelude OA gallery and the ones that showed chainplate detail show U bolts; could you take a picture of your arrangements for clarity?

Really - nothing more to show than what earlier picture shows ... and other guy who puts examples in post #2 ...

Dead simple U with plates and nuts.

 

[dac31]

Thanks all. I didnt realise how grubby the boat was until I took a picture after it has stopped raining. The mast is currently down as I have removed the anchor roller to be re-bedded and correctly backed also, therefore it is difficult to show the awkward angle that the shrouds join at.

If it is possible they are factory bent that may be the case, which makes me question whether standard straight ones would make the angle worse. I understand the original ones have lasted thus far and are probably more than sufficient, however just as the case with the penny washers underneath it makes me question whether it is the optimal scenario given the nature of the part and relatively little cost to renew. I am using Don Caseys maintenance manual which suggests that the angle of the chainplates is critical and should not flex when tensioned.

The angle on Refuelers SR25 looks more what I am trying to achieve, for peace of mind if anything.

 

[penfold]

My confusion arises as those are U-bolts to me. They shouldn't flex and the pre-bend needs to match the lead of the shrouds; that said the rig is not big and the loads won't be high.

 

[dac31]

My confusion arises as those are U-bolts to me. They shouldn't flex and the pre-bend needs to match the lead of the shrouds; that said the rig is not big and the loads won't be high.

Yes, they are plated unbolts not eye plates. If this clears up any confusion.

I would like to replace them, not knowing they could have been factory bent, preferring to replace with generic parts, I am wondering whether eye bolts would be appropriate.

 

[Refueler]

there is no need for pre-bend ... my SR25 is a lot heavier / stress than OP's and mine are straight U fittings. The turnbuckle adopts the angle needed.

 

[penfold]

Stainless steel work hardens, not prebending the U bolts is a failure waiting to happen. Just because it's not happened yet doesn't stop it being a bad practice.

Yes, they are plated unbolts not eye plates. If this clears up any confusion.

I would like to replace them, not knowing they could have been factory bent, preferring to replace with generic parts, I am wondering whether eye bolts would be appropriate.

If you mean these things I'd advise against; if you want rid of the U bolts I'd look at a length of stainless angle iron instead, but the U bolts have sufficed well enough for 5 decades.

 

[andsarkit]

Angled U bolts are not so common but here are some links to get you started:
Talamex
Blue Wave
Proboat
8mm ones will be way oversize for your boat.
As it is only a small boat I would just find some straight ones of the right size so you can use existing holes. If you get a good make such as Wichard they will be stronger than the originals.

 

[PetiteFleur]

I would use U bolts with the same leg distance, if you can find them. I replaced the U bolts on my previous Jaguar 27 as one of the nuts broke when I tried to tighten it to cure a deck leak - the original U bolts were badly corroded through the deck so replaced them all. Wichard had the correct size but expensive. Also fitted larger stainless plate inside.

 

[dac31]

Thanks for the advice all. I did struggle to find angled versions online. The blue wave look very reasonable I will measure the angle of the existing ones and get the 8mm's. Cheers.

 

[Refueler]

The angle the stays make to the U bolts is not excessive and will be fine with straight U bolts ...

My boat is from about 1973 - 5 ..... has had straight U bolts all its life as do all other Searider 24 / Sunrider 25 boats ... they have heavy masts ... more load on the U bolts than OP's fittings .... and still after all those years - no sign of any failure or weakness at all.

 

[Bilgediver]

Thanks all. I didnt realise how grubby the boat was until I took a picture after it has stopped raining. The mast is currently down as I have removed the anchor roller to be re-bedded and correctly backed also, therefore it is difficult to show the awkward angle that the shrouds join at.

If it is possible they are factory bent that may be the case, which makes me question whether standard straight ones would make the angle worse. I understand the original ones have lasted thus far and are probably more than sufficient, however just as the case with the penny washers underneath it makes me question whether it is the optimal scenario given the nature of the part and relatively little cost to renew. I am using Don Caseys maintenance manual which suggests that the angle of the chainplates is critical and should not flex when tensioned.

The angle on Refuelers SR25 looks more what I am trying to achieve, for peace of mind if anything.


View attachment 156051

That looks like a factory bent attachment as used on some Westerly boats on the lower shrouds. They are available from chandlers.

 

[greeny]

Eye bolts through the deck fitted as standard from new on Jeanneau Sun 2000. 21ft boat and probably slightly bigger rig and forces than the OP's.
I doubt Jeanneau have got it too wrong.

 

[Daydream believer]

Eye bolts through the deck fitted as standard from new on Jeanneau Sun 2000. 21ft boat and probably slightly bigger rig and forces than the OP's.
I doubt Jeanneau have got it too wrong.

Fair point. However, Jeneau would have used eye bolts of known construction. The ones usually purchased over the counter will need to be labelled with the SWL, or should not be avoided. Just an opinion.

 

[dac31]

Eye bolts through the deck fitted as standard from new on Jeanneau Sun 2000. 21ft boat and probably slightly bigger rig and forces than the OP's.
I doubt Jeanneau have got it too wrong.

Thanks greeny that is interesting. I have measured the originals as 6.4mm or 1/4 inch and approximately 15 degrees incline.

The below is a jeanneau 2000 for sale with eye bolts. I have not ordered so far but it is interesting they use this as the sideways loading makes more sense in my mind. The same as why you use d shackles Vs bow shackles for different loading directions.

 

[boomerangben]

My two reservations of eye bolts are

1, how they transfer the load into the GRP, the existing plate spreads the load, particularly around the edges of the top plate better than a penny washer would (note the Jenneau pictured has the eye bolt going through the aluminium toe rail

2. How to stop it working loose over time, particularly the cyclical loadings of a shroud.

 

[Refueler]

My two reservations of eye bolts are

1, how they transfer the load into the GRP, the existing plate spreads the load, particularly around the edges of the top plate better than a penny washer would (note the Jenneau pictured has the eye bolt going through the aluminium toe rail

2. How to stop it working loose over time, particularly the cyclical loadings of a shroud.

Sorry to labour the point - but to OP ... U Bolts get rid of all that ...

I had an eye bolt rip out of the deck of my Snap 23 .... it was factory fitted for forestay ... the nut was embedded into the stemhead GRP. The furling gear did the rest !