Masthead Sheave for Main Halyard

I have a question about the sheave for main halyard sheave at the masthead. How do I get fix this one? My Masthead mainsheet sheave appears to be frozen.

I have seen the drawing in the Ariel Maintenance Manual on page 21, and I am aware of the parts list on page 129, which appears to represent that the masthead sheave for the main halyard is part number 21076 with dimensions ½ X 6 ½ X ½, however, I am not aware of a material specification for or source for a replacement for this sheave from reading the manual or the posts on this forum. I have not been able to locate in the West Marine catalog a sheave anywhere near that dimension.

The Ariel Maintenance manual recommends enlarging the diameter of the hole through the center of the sheave, and pressing in a bronze sleeve bearing. I assume that the dimensions ½ X 6 ½ X ½ on page 129 of the manual mean that the sheave width is ½ inch, that the diameter of the sheave is 6 ½ inches, and that the diameter of the bore hole through the middle of the sheave as built is ½ inch.

I have been engaged in the effort of restoring my Ariel hull #330since September 2001. I had a surveyor do a cursory review of the hull, deck, and rigging before I adopted the boat from the Sea Scouts, and I engaged a rigger in October 2001 to modify my backstay for a tabernacle, and look over the rig with the understanding that I would further engage him to repair or replace anything he found to be in need of repair or replacement.

The bill that he submitted to me last spring reflected only his work on the backstay and backstay chain plate. I do not believe that he ever went aloft. The surveyor performed his inspection with binoculars from the dock. Therefore until today no one took a close look at the masthead. Today I did, and everything up there looks spiffy with the exception of the sheave for my main halyard. I intend to replace both my main and jib halyards with rope, but now they are wire to rope, with the connection being a bowline tied in the rope portion and threaded through a swaged eye.

As might be suspected, the swaged eye does not go through the sheaves for either the jib or the main halyards. In both cases, wire is the only material that currently runs through the sheaves. Since I now have an operational tabernacle rig, today I lowered the mast as close to the dock as far as I could lower it (eleven feet from the dock to the masthead bolt that serves to secure the two upper shrouds and also serves as the axel for the main halyard masthead sheave). The jib sheave appears to be in good condition, and it works smoothly, but the main sheave does not appear to move when the halyard wire is pulled through it. In other words, the sheave appears to be stuck, frozen, jammed or however it is proper to describe something that does not move, but is supposed to do so.

I am drawing these conclusions by standing on the trunk cabin on another boat, and looking up about six feet. I will shortly pursue options that afford me a closer look, but it appears that the main halyard sheave is scarred by the wire halyard. The sheave itself, when viewed through the slot in the front of the mast, appears to be rusty.

The main sail is extremely difficult to raise, but I have done so on sixteen occasions, since I began sailing the boat on Labor Day last month. Yesterday, I reefed the main in about 20 knots of wind while single-handing, and it was possible, but again not exactly a piece of cake. My guess is that I am, by brute force, dragging the wire halyard through a frozen sheave. I have no halyard winch for the main, although there is a jib halyard winch on the port side of the mast, so I am pulling the main up by hand, but it feel like it takes a lot of force to get the main up all the way. Actually raising the main is fairly easy until the last five feet or so, provided that the mainsheet, downhaul and boom vang are slack. Then it gets tough.

I don't want to drop the mast to inspect, repair or change out the sheave. Due to lifting limitations I would have to pay a yard to have unstep and restep the mast with a lift, but I might be able to use my tabernacle to lower the mast to a raised dock where I could repair or replace the sheave.

Has anyone else had to deal with a malfunctioning masthead main halyard sheave, and how did you deal with it? Changing a sheave does not seem like it would be too difficult undermost circumstances, but I do not have specifications for this sheave, and the axel on this sheave is also the support bolt for the upper shrouds, so removing the axel would leave me with no lateral support for my lowered mast during the repair or replacement. Any advice will be appreciated

Scott,
You gotta take the mast down for a proper inspection and repair .
If you can use an halyard from your neighbors boat it will be easy .
Lower your mast , make a bridle and attach the halyard from next door , release your mast and lower to your deck and pier . 2 guys can carry it with a little sweat .
If you can get alongside a dock , a truck with a 'cherry picker' or bucket truck , can lift your mast off , it ain't brain surgery .

I might have access to a raised dock. I might be able to lower the mast to that dock, using my own tabernacle system, rest the masthead in some sort of cradle, and replace the main halyard masthead sheave if necessary.

Certainly, the other alternative would be to unstep and drop the mast totally, but that is not an alternative I am pursuing. What isn't braion surgery to one person may not be physically possible to a person with lifting limitations. If I were to unstep and drop the mast, I would need to do that in the local yard, at which time I would be doing a lot of other things to the boat also. I am not interested in scheduling yard time right now.

Furthermore, it would make no sense to remove the mast until I have replacement parts in any case. I simply want to repair or replace the main halyard masthead sheave, and it is about the sheave that I am seeking information in this thread.

I am seeking information from other Ariel or Commander owners who have replaced their sheaves, or have otherwise made them functional again once frozen. I am interested in knowing how they went about the work. I am also interested in a source for a new sheave, since the only local vendor of such things (West Marine) doesn't seem to stock anything similar.

So:

1. Does anyone have a specification for or source for a main halyard masthead sheave?

2. Has anyone out there replaced this sheave, and how did you do it?

Any responses to the above questions will be appreciated.

Scott:

I have disassembled the entire main halyard assembly, including the sheave. Mine has all the original parts. My comments are limited by my memory. The sheave runs between two closely placed aluminum plates, and wears against those plates. I lubricated the assembly with white lithium grease. Specifically, I lithium greased the surfaces where the sheave runs against those plates.

I also greased the bolt that goes through the sheave and the plates.

I would caution you against taking apart the assembly anywhere near water. If a part drops that you hadn't figured would drop, you have a replacement problem.

Also, I would be concerned about raising the sail if the sheave is frozen. Reason 1: That wears one side of the sheave and you might have to replace it if it wears to badly. Unless you know the groove is really badly worn, there should be no need to replace the sheave, and even then I wonder if there is any need to. Reason 2: If you need to get the sail down quickly, the last thing in the world you want is for halyard to jam or be difficult.

As an interim repair, drop the mast to the extent you can get to the sheave. Try turning it. Does it turn at all, or just with difficulty? Spray liberally with in WD40, work it a bit, and see if that frees it up. Normally I suggest that you remove the bolt, but unless you are on land, you can lose parts - so don't do that. It is a rather touchy assembly. However, spray enough WD40 on the assembly so that the bolt is soaked where it passes through the sheave.

Remembering that WD40 is not really a lubricant, once the sheave is freed up, spray it with white lithium grease. If that doesn't work, soak it with sail track lubricant that you can get at West or any marina that is non staining. However, the lithium grease is better for this purpose than the sail lubricant.

In short, I think you have a lubrication problem from what you are saying, not a part failure.

As for the jib halyard block, visit my comments about that block posted this past August. That was the only block I hadn't replaced, because it is metal, and that was the one that caused my grief. Shaeffer still makes that block for a wire halyard (if you go the wire route) and it only costs about $40.

The eye of the jib halyard should pass through the the top of the pulley assembly, between the sheave and the shackle. If it doesn't check to see if the head of the block (the shackle assembly) can be detached so that you can put the halyard around the sheave, and then replace the shackle assembly. If not, you need the new Shaeffer fitting or a new eye assembly.

As for the main halyard, the line, at least, probably is not original, or it broke on a prior occasion. Mine is original, and there is no bowline knot in the line attached to the wire connection fitting. The line is spliced.

Incidentally, regarding the main halyard, I plan to replace both the wire and the line in my main halyard assembly this fall/winter at West Rigging. When it is done, it will look just like the current halyard assembly, using the metal connector and the halyard shackle, except that the line will not be white but colored flecked. In other words, I am replacing the wire and the line, but not the fittings.

The reason I raise this is that, if you want to do the same, and want West Rigging to do it, I can tell them when I send in my current assembly as a model to duplicate, that you will be ordering one just like mine, and they can make two, one for each of us. The reason I am getting a new one is that the line is looking pretty old/questionable. The wire looks fine, but if I am doing one part, why not do the other at the same time.

Hope this helps.

Theis,

Your diagnostic skills are near perfection.

I removed the forward hatch today, so that I could lower the mast an additional foot or so using my tabernacle rig. I then accessed the masthead by step-ladder from the dock. Although an earlier attempt to pull the halyard through the sheave yesterday under tension demonstrated that the sheave was not moving, today with the masthead a few feet closer top me, I was able to get the sheave to move by pushing on it with a screwdriver. I made one revolution of the sheave and inspected the sheave as I went. .I could see no areas of excessive wear, although the sheave is scarred by the wire halyard that has been running through it for who knows how many years.

Instead of WD 40, I used a product called Corrosion X. It is messy stuff, but I freed my tiller head/Pepsi can shim/ assembly with the product, so I applied liberal doses of corrosion X to the masthead sheave. In short time, I was able to turn the sheave freely. I applied the product about four times or a thirty-minute period, and each time the sheave moved more easily, until I was satisfied with the motion, and the halyard under tension when pulled through the sheave caused the sheave to move.

Incidentally I used the same product with some bronze wool to clean the corrosion off the masthead upper shroud tangs, and the upper portion of the shrouds. I also used Corrosion X to clean the metal parts of the jib halyard block, which appears to be in good shape.

I will follow your suggestion and use lithium grease on the main halyard masthead sheave.

After I raised the mast again, the sheave worked freely, and raising the main was much easier. (No more feeling of pulling wire against fixed metal, and much less resistance to raising the main than there was before.) So you are absolutely correct. I was not dealing with a parts failure, but only with the effect of corrosion.

Although I have owned my boat since September 5, 2001, I spent he past year restoring the decks, hull/deck seam/ gelcoat on the toe rails and cockpitm restoring the interior, and effecting rigging changes related to the tabernacle. Although I asked a rigger to inspect my rig, as I said earlier, I don't believe that he ever did in the eight months I that he took to finish his work to his satisfaction because he billed me only for his work on the backstay and backstay chain plate. A reasonable charge, but not inclusive of the inspection that I requested. In any case, today I got a fairly close look at the masthead, and things look pretty good up there. I will probably drop the mast next spring when I haul the boat, repaint the mast and do a complete review of the attached hardware and rigging. Incidentally, at some time in the past someone re-rigged my boat since it has Norseman fittings on the wire. It was not until Labor Day this year that I finally had the motor serviced and installed. My first sail in Augustine was on Labor Day, so I am still discovering things, some of which like the subject sheave give me cause to pause.

As you noted, the running rigging is not original. There is no way that the eye on the jib halyard will go though the block. I am sure that a rope to wire splice would. The wire on my boat is too long in any case. It takes four wraps of wire around the jib halyard winch with the 90% or 110% jibs raised, or you would be wrapping wire around the jib halyard cleat. I appreciate your offer of a joint purchase of wire/rope halyards, but instead I have decided to go with Stayset-X and do straight rope halyards as recommended elsewhere in the forum. It appears to me that both the jib and main halyard sheaves will accommodate 3/8 inch rope as per the original specification, and probably half inch, which I would prefer.

Your suggestions on the main halyard sheave were of considerable assistance, and will be of even greater assistance later when I recondition the mast. The paint currently on the mast is apparently quite corrosion resistant, but has no resistance to UV light whatsoever, and is in the process of turning to a buff colored dust that settles down upon and stains my mainsail cover.

So thanks for your response. As a result of an anti-corrosion product, I was once again able to go for a sail tonight when I finished cleaning up my mess. The ocean was beautiful tonight. Augustine left three thirty foot sparkling blue wakes behind her, one at the surface from the OB motor, and two more (one on each side of the boat) from the rudder and keel. I could lie on the lazarette hatch and see the sparkling blue light swirling from the rudder beneath the transom. The Milky Way overhead, the hovering midnight-black pelicans, and the sea lions running straight for the boat in imitation of torpedoes and glowing with bioluminescence were a spectacle to behold. It was great to be able to lie back in the cockpit with the tiller in my hand and stare up at the Milky Way as pelicans hovered overhead and Augustine made her way southeast trailing a wake in perfect imitation of the stars above. Thanks for your post on this subject. At 11:00 PM tonight at the end of the sail, the main dropped down it's track like a rock. Corrosion X is great stuff. Now for the lithium grease.
;)

Pleased I could be of help. We are getting ready to pull Solsken for the winter. The season is over. It is sort of like preparaing for a funeral. A sad time of the year.

Theis,

The anti-corrosion product that I used was called Corrosion Block and not Corrosion X as I previously reported. I greased up the main halyard masthead sheave today with white lithium grease (Orchard Supply Hardware for $4.95 per can), and the sheave now moves smoothly and with no perceivable resistance. Thanks for the advice.

My neighbor at the harbor tells me that he has had great luck with lithium grease on his trailer winch. I applied the grease by spraying it into the aperture on the aft side of the mast, and also by applying it from the aft and forward side using the little red straw that comes with the can. However, the gap between the two aluminum plates and the sheave is very narrow, so it would be difficult to determine how much grease actually got down into the space between the plates and the sheave, and down to the bolt without disassembly. Scraping the lithium grease makes a fair amount of a mess, but I wiped off the excess, and allowed the remainder to soak in for a while before I cleaned up the groove in the sheave.

Incidentally with the forward hatch removed temporarily, I was able to lower the mast to about nine feet off the dock using the mainsheet on my tabernacle rig. By standing on the fourth step of an aluminum step ladder, I was able to easily reach the sheave, and also the very top of the mast head so that I could inspect the various attachments, and replace the wind direction indicator, which was long since destroyed after being sat upon by a sea gull I suppose.

Sorry that you have to close up the season there. Out here, the bioluminescence was grand last night. I took off for a single-handed night sail after I removed the corrosion on the sheave. I stayed out till about 11:30 PM. I was trailing a bright blue wake of 30 feet in length from the OB motor, and it was shadowed below by two additional deeper wakes from the keel. It was so clear and bright that you could see the reflection of the Milky Way on the surface of the sea. When I finally turned to run for home, Augustine's blue wake was the perfect echo of the Milky Way.

Beside me, the sea glistened with small blue stars flashing in imitation of the myriad stars overhead. Just before I reached the harbor, a sea lion came shooting toward me and passed under me like a brightly illuminated torpedo.

We reached the dew point mid-sail, and the sails and everything on deck were drenched by the time I reached my slip. That included me of course. The boat looked like a clothesline today with sails, jacklines, emergency boarding ladders, etc hanging in the sun on this 85+ degree day.

Maybe I should move down there!