Hardware Nomenclature

[sailak]

Howdy,

The wife and I were replacing the last piece of new running rigging on the boat this week and as I hoisted her up the mast the sheave in the turning block for the halyard I was using shattered. Wonderful.



I knew the sheaves were getting bad, they were on the list but I just hadn't gotten around to them yet. I will be replacing all of the blocks at the mast base and will probably add one or two just to have them available if needed. As you might notice in the photo below the blocks at attached through the fitting at the mast base (what is that fitting called?) I do not see any way to replace only the sheaves, the "axle" is a rivet/pressed piece, I don't know of a way to take the block apart.



It's a bit of a pain to have to raise that large fitting to replace or add blocks. Is there some kind of hardware that can attached to the fitting that I could then attach the blocks to? Perhaps something with a pin or bolt securing the block.

Any recommendations on brands or types of blocks?

Thanks

[Fstbttms]

It's called a "mast plate" but yours is atypical, in my experience. Generally, they look like this:



and you would use blocks with swivel shackle so that blocks are easily added or removed and have a wide range of motion.

Your block with the broken sheave is a goner and will have to replaced. Harken, Schaeffer and Ronstan are probably the most popular brands.

[sailingfool]

IMHO definately Garhauer...can't be beat for price and quality. Plenty of threads on the board.

Garhauer Marine Hardware -1463898

I assume Guido is still there, email him you picture and take what he recommends, it'll be half the cost of comparable Harken or Lewmar and just as good. if you blocks of similar make and age in your mainsheet or mast head, replace all those also, they will be failing.

[Fstbttms]

Originally Posted by sailingfool

...it'll be half the cost of comparable Harken or Lewmar and just as good.

Oh yeah, forgot about Lewmar.

[sailak]

Fastbottom,

Appears you have a deck-stepped mast, mine is keel-stepped. Would be much handier just having the holes around the edge of the plate.

[Vasco]

This looks like a keel stepped mast, an Isomat. What the OP is asking for is the threaded studs that the blocks are attached to. These cost about $40 a piece from Rigrite. It would be easier to drill out the rivets in the blocks and use the same studs to shackle a Garhauer block on. Check the link out. No need to raise the mast, just remove the halyard and turn the blocks (to the left) and they will come out. There is a nut that is captured in the slot at the base of the mast. If you check, each round hole has a slot under it. The nut is in the slot and will not turn when you turn the blocks.

Isomat Mast Base Turning Blocks

[sailak]

Thank you Vasco, that is exactly what I was looking for.

My boat originaly had an Isomat mast, currently has an Hall spar.

[Vasco]

You're welcome. The good pics did the trick.

[jbondy]

Also called a halyard organizer plate. Rather than sit under a deck stepped mast, yours looks like it's attached to the deck and also serves as the partners, if I've got my terminology correct.

I keep looking for one that's made for keel stepped masts. It would fit around the mast like a two part collar and be attached to the mast. The profile would have to be specific to the mast, but I'd think there'd be a market for it.

[sailak]

Ok, finally getting around to this project and have run into a bit of a snag. (not surprising - it IS a boat project )

Normally the block has a 1/2 inch diameter threaded stud that inserts thru the mounting hole in the collar and meets with a nut slid in through the slot at the bottom of the collar.

Mine however has a sleeve inserted through the collar from below. This sleeve is "capped" on the end with what appears to be a nut and the inside of the sleeve is threaded for an M8 metric stud.

The problem is I can't find any blocks set up in this manner. I've tried Harken, Garhauer, USSpar, Charleston Spar and Rig Rite. No one carries anything like what I need, most have never heard of such a thing.

My question, how big of a deal is it to slide the deck collar up the mast a bit? From looking at it there are 4 bolts holding it to the cabin top. I'm assuming it is tied into the mast to counter the "pull" from the lines that run through the blocks. Thoughts? Warnings? I've got a rigger coming in a couple of weeks (local yacht club brings a couple guys up from Seattle each year) so I'll have professional help doing this.

Here's a couple photos showing the sleeve and block attachment:





Thanks in advance!