Halyard Blocks

[seasickwhale]

Hello everyone,

in my new album

http://www.capecutter19.org/forum/album.php?albumid=18

I have posted a few pictures of my replacement for the inadequate South African halyard swivel blocks.

[erbster]

I have heard that the halyard blocks on SA boats have broken under load in some cases. Has anyone with an Honnor boat experienced this?

Today, whilst sailing on a close reach in f3/4, the main halyard block parted company from the deck.

The pressed steel shackle which attaches to the block was apparently only riveted to the stainless deck plate. I am planning to fix this by using a stainless bolt and nyloc nut to reattach the shackle.

[Ru88ell]

I think people put a stainless steel eye bolt through the deck and plate. That's what I have.

[erbster]

Do you mean that the bolt goes through the coach roof with the nut in the cabin, does the nut go behind the external plate on the coach roof?

[Dennis]

Hello Charles

I have just carried out the mod on Mary Ann.

Mine had not yet failed, but I estimated that one side would have done so this season if I did nothing.

I used a M6 countersunk head screw through the plate only (not the deck) with an eye nut on top. (There is sufficient space under the deck plate for the csk head of the screw, but not for a conventional head or nut)

No extra holes in the deck.

Topped it all off with new blocks directly attached to the eye nut

[erbster]

Thanks for that Dennis. I can understand why you don't want to use the old pressed steel fittings to connect to the block. Why do you need a countersunk bolt? I was thinking just a flat head one. I know the block should not need to rotate, but is a washer necessary? Was your eye nut a nyloc one to stop it unwinding?

[Dennis]

Why do you need a countersunk bolt? I was thinking just a flat head one. Was your eye nut a nyloc one to stop it unwinding?

Hello Charles

The only reason I used a countersunk screw (not bolt, a bolt has a plain non threaded shank undeneath the head, a screw is threaded all the way to the underside of the head) is the limited space available under he raised part of the deck plate. If I had used a hexagon headed screw I would have had to file the head down to make it fit. The csk. screw fitted without modification, apart from cutting to the desired length.

I have never seen a nyloc eyenut, this is what I used:

http://www.s3i.co.uk/EyeNut.php

With regard to unwinding, I just make sure it is damned tight. If you want belts and braces, you could use loc-tite.

[erbster]

Thanks for that link, Dennis.

[erbster]

I have made a repair to the fitting, but I may. Only use it temporarily- I have used a countersunk m6 bolt and by lock nut to reattach the "stirrup" fitting which was previously riveted to the deck plate.

I looked at the http://www.s3i.co.uk/EyeNut.php link (ooh, such a lot of shiny stainless bits and pieces!!), Dennis. Did you use M6? Having had this fitting pop, I'm feeling a lot more nervous about the load on both of the halyard turning blocks. The SWL of the M6 eye is 70kg. Is that really enough?

I was wondering about using an eye bolt (threaded end cut to size) http://www.s3i.co.uk/EyeBolt.php. I could then fit a nylock nut behind the plate. To accommodate the nut, I would make a small hardwood patress, which could have a recess in the centre. I also wonder about using M8, which would double the SWL to 140kg.

What does the collective wisdom think?

[Dennis]

Dennis. Did you use M6? Having had this fitting pop, I'm feeling a lot more nervous about the load on both of the halyard turning blocks. The SWL of the M6 eye is 70kg. Is that really enough?

Hello Charles

It was the "Lifting Eye Nut" which I pointed you toward. The low SWL is low because it has to have a guaranteed large factor of safety for H and S reasons.

If you look at the M6 "Commercial Eye Nut" which is not as strong as the "Lifting Eye Nut" it has a breaking load of 990Kg.

The material that the eye on the M6 "Lifting Eye Nut" is made from is 6mm dia, whereas the M6 "Commercial Eye Nut" is only 5mm dia.

If you look at the M8 "Commercial Eye Nut" it is made from 6mm dia material the same as the M6 "Lifting Eye Nut", and it has a breaking load of 1300 Kg.

You could lift your boat up with that.

To answer your question, yes I did use M6 "Lifting Eye Nuts". As you can probaly tell from the info I have given, that I consider them to be more than adequate for the job, and many times stonger than the original fitting.