Masthead Sheave vs boom bail and block

[Skip Henderson]

Not sure I can restore my mastsheave and plates for use. Plus, I need to get the mast stepped and boat out of the yard ASAP. I'm considering the alternate use of an adapated boom bail and block rather than the masthead sheave for the main halyard. Any suggestions, advice, forewarnings would be appreciated.

What constitutes an un-usable sheave? chipped edges?
If using a block, what type do I need to retain use of my wire/rope halyard?

Thanks! Skip

[commanderpete]

Found a picture of cjackson's mast head. I forget what it looks like up there.

The first hole on the left is for the backstay.

Under that is a hole for a clevis pin to hold the topping lift block.

Is there enough room under that to drill another hole to hang a block? Then get rid of the sheave cheekplates that stick out.

I would try to use the original sheave if at all possible. How bad could it be?

[bill@ariel231]

A-231's masthead looked pretty bad until I disassembled and cleaned/sanded/greased the parts. It still works fine with a few nicks and dents in the sheave. You may not need to do anything a drastic as run a block external to the mast...

[Skip Henderson]

Thanks Bill. I got the sheave out and will take some pictures tomorrow to post. It is well knicked but otherwise seems solid and true. Along with the photo I'll ask the question whether or not I should attempt to sand or file down the knicks to smooth edges etc. The question is which is of higher value, smooth edge or grove depth. As an aside, after years of just sailing with little maintenance and upkeep, it's nice to get personal with the old girl again.
Skip

[Skip Henderson]

At the moment I'm going for re-use. Your question is apt. How bad can it be? Unless I'm courting a jam it would seem that the worst case is muscling it through.
Skip

[bill@ariel231]

skip

I've been using the original sheave with 3/8th braided line with no problems or hangups. The original profile on mine appeared to be a half round profile (appropriate for rope). I expected a V-grove profile since wire halyards were fitted on the boat when I bought her...

good luck,
bill