The right shape of halyard-sheave groove

[zoidberg]

Replacing a pair of halyard sheaves, I'm presented with two profiles - rounded and V-shaped. What's to choose between them - and does it really matter?

 

[john_morris_uk]

One’s for wire and one’s for braid line etc?

 

[bedouin]

I think it is V for wire and U for rope

 

[Gsailor]

Interesting question and the answers given are undoubtedly correct but would a v shape not only work for braid but also give additional ‘safety’ in that the halyard would take the v shape and be less likely to slip out of the rounded sleeve?

I do tend to overthink things and be a little odd.

 

[bedouin]

Interesting question and the answers given are undoubtedly correct but would a v shape not only work for braid but also give additional ‘safety’ in that the halyard would take the v shape and be less likely to slip out of the rounded sleeve?

I do tend to overthink things and be a little odd.

I think the limited contact area from braid in the V shape would cause a lot more wear on the halyard - the U profile distributes the load/wear more evenly.

Conversely wire in a U sheeve will tend to cause a lot of wear to the sheeve - cutting a groove in it

 

[Gsailor]

I think the limited contact area from braid in the V shape would cause a lot more wear on the halyard - the U profile distributes the load/wear more evenly.

Conversely wire in a U sheeve will tend to cause a lot of wear to the sheeve - cutting a groove in it

Yes, I imagine you are right.

The thought of a halyard jumping out of groove and jamming would worry me a lot more than wear and tear but I accept that I am odd, overthink things and probably do things that are not necessary.

 

[William_H]

A decent sheave block or box with close parallel cheeks should not present a problem for wire or rope jumping off. It is perhaps when cheeks wear or get damaged or perhaps never close in first place that wire or rope can escape. ol'will

 

[zoidberg]

I think the limited contact area from braid in the V shape would cause a lot more wear on the halyard - the U profile distributes the load/wear more evenly.

Tracked down the originals, from Selden,

Their product No. 504-325 has a V-groove and seems is their offering for both wire AND braided rope.