Thing at End of the Boom with Broken Sheave

[and4ew]

What's this thing at the end of the boom called? The sheave for the outhaul is broken, i.e. a lost of the edges of the sheave itself are chipped away/missing. There are two other sheaves, i.e. three next to eachother. The centre one is for the outhaul, the other two are for reefing.

Sorry I don't have any better pictures but would I likely have to replace the whole thing (whatever it's called) or would it likely come apart?

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[marcjsmith]

I would call it an end cap or a boom end fitting


i know on my kemp boom fittings i can remove the sheaves, clean and replace.


who s the manufacturer of the boom/mast. looks like it was made in france, but I don't recognize the partial logo..

[Ferrity]

I have Isomat spars (mast and boom) on my Bayfield 36. If I am seeing the second picture correctly, once you remove the line, the axle & sheave assembly lifts out from the top. Note the grooves on either side of fitting. Same is true for mast end sheaves.

I see that you are in Canada, otherwise I would recommend Don Green in Virginia to make new sheaves.

Dennis
s/v Ferrity

[psk125]

Rig-Rite calls them "outhaul assemblies" and seems to have them in different sizes according to the dimensions of the boom. Ferrity's advice about trying to pull the axle out and replacing the sheave that way is the place to start, however. You don't really need a whole new boom end fitting.
https://www.rigrite.com/Spars/Isomat.../NB16_boom.php

[Marathon1150]

Originally Posted by Ferrity

I have Isomat spars (mast and boom) on my Bayfield 36. If I am seeing the second picture correctly, once you remove the line, the axle & sheave assembly lifts out from the top. Note the grooves on either side of fitting. Same is true for mast end sheaves.

Dennis
s/v Ferrity

Ditto for Selden booms on both of our Beneteaus. The sheaves lift out from the top of the boom after removing lines. There are quite a few sizes of these things so having precise measurements is important. I replaced three on one of our boats (and will be doing the same on the second) for the same reason - most of the sides of the sheaves have disappeared. I got lucky the first time because the hardware supplier took a guess at what size I needed based on boat, size and year.