mast sheaves

berwick · **Joined:** 21 Oct 2006 18:12 **Posts:** 325

I gotta stop reading books - In the complete riggers apprentice (Brion toss) he mentions about problems of wear when you use all rope halyards with the older rope/wire sheaves that are on our masts.
Does anyone know what spar company made our masts?
Also does anyone know the sizes of the sheaves, how easy/difficult it is to change it, and where to get parts if the original company is not around.
Thanks
Richard

Sam · **Joined:** 31 Oct 2006 19:43 **Posts:** 37

Dear Berwick,
I have a 1977 boat #52, that I have owned since 1990 and I have been using 7/16ths StaSetX halyards all along. I do not consider it a problem, and I have not seen any wear on the ropes. I tie on the snap shackles and headboard shackle with Buntline Hitch knots rather than Double splices because the splices can be larger and stiffer than the rope halyard and jam in the sheave opening at full hoist. The mast must be down to change the sheave and the top probably should be pulled off to access the sheaves. My sheaves are solid aluminium with hard bushing bores so there is not much to go wrong with them. I have included a few pictures to show what you will be looking at. My mast is an Annapolis Spar with a Schaeffer boom.

Rani · **Joined:** 19 Aug 2015 03:31 **Posts:** 5

Hi,
I have Hull number 9 1978. I need to change the sheaves apparently. I have a bloke who says he can do it without pulling the mast out.

Trying to find out where I can get them and how to get the right ones.

User

Rani · **Joined:** 19 Aug 2015 03:31 **Posts:** 5

Oh yeah.... I'm in Australia. Confused

jvoelxen · **Joined:** 21 Oct 2006 15:36 **Posts:** 268

I have hull no. 191. My masthead/sheave shaft arrangement is much different from shown above. Attached are some pictures showing the mast head of my boat. The sheaves are made of aluminum with brass bushings at the shaft. There is a single stainless steel shaft for both sheaves. The stainless shaft has a flat, thin plate about 1 inch long welded the shaft. A hole in that plate has a stainless steel bolt that attaches the plate with shaft to the mast. My pictures show the shaft holes and bolt. The fore and aft shafts w/small plates are removed. In one of the pictures you can see the shaft hole of a sheave as you look through the shaft hole.

Getting the bolts out that hold the shaft assemblies was a challenge as seems to always be the case with the dissimilar metals. I had to use some heat and PB blaster. Hard to imagine getting that accomplished with the mast stepped. All 4 of my sheaves were in excellent shape. Hard to imagine that they're worn if they are aluminum like mine.

Velera · **Joined:** 29 Dec 2006 09:38 **Posts:** 656

Just curious--what did the bloke say was wrong with them? They are quite hard to wear out--my boat has been heavily used and cruised for all of its 33 years and I have never seen and signs of wear. I have the sheaves with grooves for wire and use some 7/16ths StaySet and have never had a problem. I have taken the whole thing apart and I frankly cannot imagine doing that while in a bosun's chair. It is not difficult but stuff falls out unless you have three hands up there. I am #373 and I think they had several different mast vendors, so things might be different. i have seen sheaves for sale in some supply stores, but finding the exact thing might be a trick. I would take the old one and have a machinist turn a new one one for you. Probebly less money and hassle than chasing the exact thing.

Ray

Rani · **Joined:** 19 Aug 2015 03:31 **Posts:** 5

Thanks guys.
I still haven't done anything about this.
Had a rigger climb the mast and look recently.
He said the aluminium sheaves were seized.
He thinks he can fix the problem without pulling the mast.
I'll let you know how that goes.

Tartan37.com

mast sheaves

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