Failed lewmar block

[Jmc1764]

After only 50 years of service the pulley has shattered during a force 10 ! I think its out of warranty now but would like to fix it. I can't seem to find a replacement and it would be nice to keep its sun burned faded look to match the other side.
I can't see how its possible to replace the pulley as it looks like its pinned together, has anyone taken one of these apart before ?

 

[MoodySabre]

Well you can buy if you can afford them
Lewmar Ocean Snatch Blocks
you will see that there is a nut on the top. So you could grind off the pin, replace the sheave and refix with a bolt.

 

[bignick]

Only 50 years? I’m appalled !!!
you should write to Lewmar and complain.

 

[Neeves]

Have a look at interscrews. They are used in children's playground equipment so I think they will be man enough (but check) and the ones I have seen are stainless and 'low profile' so do not protrude. They do not take kindly to lateral loads - but that should not be an issue on a block. You can chop them back for your application.



Sorry but these were sourced in Oz - not much use to you - except the lower right hand device (used by X Yachts to secure our sheet winches)

I was looking at their use in an anchor attaching device (shackle replacement). It was low profile for skinny bow rollers - and thus perfect - but did not take lateral loads. A brilliant idea - that wasn't

Jonathan

 

[RunAgroundHard]

Don't reuse it. The cheeks have degraded due to UV light, the block is dangerous, even if you machined a new sheave and fitted it. A catastrophic failure under load could have unpleasant consequences beyond just a broken snatch block.

I bought mine on eBay, about £50 each, in good nick, it's worth keeping a watching brief for them second hand as new price is too expensive.

 

[ean_p]

Don't reuse it. The cheeks have degraded due to UV light, the block is dangerous, even if you machined a new sheave and fitted it. A catastrophic failure under load could have unpleasant consequences beyond just a broken snatch block.

I bought mine on eBay, about £50 each, in good nick, it's worth keeping a watching brief for them second hand as new price is too expensive.

I'm not sure you could have a 'catastrophic' failure caused by failure of the cheek blocks . If they 'disappeared' totally the rope would still be retained by the strap work / steel work of the block. It might not run free but shouldn't allow significant change to the status / position of the rope. Looks like an ideal candidate for a repair !
P.S if anyone has any in a similar state they don't want I'd happily accept them please!

 

[bristoljim]

After only 50 years of service the pulley has shattered during a force 10 ! I think its out of warranty now but would like to fix it. I can't seem to find a replacement and it would be nice to keep its sun burned faded look to match the other side.
I can't see how its possible to replace the pulley as it looks like its pinned together, has anyone taken one of these apart before ?View attachment 142399

Can you come up with the outside diameter - thickness - pin diameter.I have a selection of Lewmar refurb kits
for ordinary blocks which may contain a sheave the right size - you never know your luck.
Jim

 

[Boathook]

After only 50 years of service the pulley has shattered during a force 10 ! I think its out of warranty now but would like to fix it. I can't seem to find a replacement and it would be nice to keep its sun burned faded look to match the other side.
I can't see how its possible to replace the pulley as it looks like its pinned together, has anyone taken one of these apart before ?View attachment 142399

I have repaired mine by removing the pin, new sheave and used a bolt with a nyloc nut. I do like the idea of Neeves to use interscrews as especially the nut is proud of the cheeks.
Unfortunately though yours are DANEROUS as part of hinge is missing on the 'shackle' part.
This was a known defect 40 years ago with this and in those days Lewmar handed out spare 'shackles'. They are removed by removing the black collar using a thin blade to separate the ring. the shackle part then drops down allowing removal of the 2 collets. Whether spares are now available I don't know.

Edit.

Picture showing 'shackle' in bits with a complete hinge. The shackle was an universal use item, in this case on a ring and this is connected to a wire strop not shown in picture.

 

[bristoljim]

Can you come up with the outside diameter - thickness - pin diameter.I have a selection of Lewmar refurb kits
for ordinary blocks which may contain a sheave the right size - you never know your luck.
Jim

The sheave may run on a spacer rather than the pin ?
Jim

 

[Boathook]

The sheave may run on a spacer rather than the pin ?
Jim

I seem to remember that it does run on a spacer this stops the cheeks crushing the sheave.

 

[Neeves]

If you are using interscrews in load bearing application - make sure the male portion fits as well as possible to the end of the female portion as then the male portion takes any load relatively evenly.

Jonathan

 

[andsarkit]

Unfortunately though yours are DANGEROUS as part of hinge is missing on the 'shackle' part.
This was a known defect 40 years ago with this and in those days Lewmar handed out spare 'shackles'. They are removed by removing the black collar using a thin blade to separate the ring. the shackle part then drops down allowing removal of the 2 collets. Whether spares are now available I don't know.

That is interesting. I have some Lewmar shackles of that vintage that exhibit the same problem with visible cracks although not yet broken. I assumed they had been overloaded at some time and didn't realise there was a design/manufacturing fault. It is probably too late to get them replaced now.

 

[RunAgroundHard]

Good comments and observations from Boathook and andsarkit. I'll now check mine closely as result of their comments and pictures.

 

[Boathook]

That is interesting. I have some Lewmar shackles of that vintage that exhibit the same problem with visible cracks although not yet broken. I assumed they had been overloaded at some time and didn't realise there was a design/manufacturing fault. It is probably too late to get them replaced now.
View attachment 142449 View attachment 142451
View attachment 142452 View attachment 142453

Thats how mine went. At the time everything on the boat was lewmar and they were shocked when I asked for about 15 replacements. If the pin is removed, (the head is preened over), would it be possible to weld up the crack and put a bolt and nut back. I don't know enough about welding.

 

[Jmc1764]

Thanks for some great info and advice. I think I am going to have to bite the bullet and buy a couple of new ones, although I can't afford the Lewmar ones the local Pirates Cave has some cheaper Barton and Harken blocks that look ok but not with the snap lock.