Sheave replacement

[Jason K]

I know this seems like a simple, straightforward thing and that it doesn't deserve it's own thread, but this is turning out to be far more complicated than I would have thought.

Like many Tritons, the J/30 is a fractional rig. I don't have a boom topping lift, so the main halyard is the only way to go up.

I recently replaced all of the halyards and I inspected the sheaves for the spin and jib halyards - they look pretty good. I'm going from wire/rope halyards to all rope. I did not want to go up to the top of the mast on an ancient halyard with no safety line, so I just crossed my fingers and hoped that the main halyard sheaves were equally decent.

They aren't. On the first hoist with a brand new Warpspeed halyard, it jammed. Repeated efforts to get the sail up (we were out for a race) chewed the cover of the halyard in two spots (photo below).

I tried replacing it with an old, tough Sta Set X halyard to get out on the water tonight, but now even that won't feed through the sheave.

Incredibly, it looks like I have to drop the rig to replace two $30 sheaves. To get the full update on the sheave issue, go here: http://www.rambunctiousracing.com/sheaveissues.html

I'll have some photos of the unstepping over the weekend.

[Tony]

Wowee.
I don't suppose there's a high pier you can pull up to to reach the top of the mast...

-Tony

[jollyboat]

Hold the Phone - Whoa - Jason when did you get a J-30! ? Sorry I missed that day in school. Awsome, I love those boats !!!

[Jason K]

Brian,

Early May - how'd you miss that memo? :)

I'm having a great time with the boat. It's really been a lot of fun.

[Jason K]

OK, the rig came down yesterday and it revealed some interesting surprises. I'm glad I dropped it. Not only did I get to take care of a number of projects, it's good to know everything up there is in good shape. As we don't have the seasonal sailing many on this forum do, it's actually fairly rare for a rig to come down here for maintenance. I can't begin to hazard a guess as to the last time this rig was unstepped, it's certainly been many years.

I have a write up from yesterday's fun along with a number of photos here: http://www.rambunctiousracing.com/mastwork.html

The primary reason for dropping the rig was to find out what was jamming and cutting the main halyard and to fix the problem. I assumed that it was a sheave issue. The real cause surprised me.

The main halyard runs through two sheaves and then drops into the mast. The first sheave is in the mast crane. The second sheave is in the center of the mast. The second sheave serves to guide the halyard down into the mast without chafing on anything.

At some point in the past, the secondary sheave (the one in the mast section) seized. Its bearing was caked with dirt and the sheave would not rotate. Rather than remove the sheave and clean or replace the bearing (which is nothing more than a small bronze sleeve), it was decided to simply bypass the secondary sheave. Bad, bad idea.

Rather than running cleanly into the mast, when the second sheave was bypassed, it ran against the top of the mast extrusion, inside the channel for the mainsail's luff. As it was a wire halyard, it carved a sharp-edged, v-shaped groove in the soft aluminum. Truly, I can't think of a more efficient shape for jamming and cutting line. The photos below show the groove with the messenger line caught in it. With the new sheaves in place, this groove will be bypassed, so the problem is solved. Also, the groove is far too small to have any effect on the strength of the mast.

I also replaced the lightbulbs, retaped the spreader boots, cleaned the filthy mast base and mast step, replaced the mast boot, shimmed the mast farther aft in the partner, removed the mast head wind instrument for rebuilding, replaced the wind vane, cleaned the rig, and gave everything a careful inspection.

The two photos below show the groove carved by the old wire halyard:

[Rachel]

What a crazy "solution" for a seized sheave. Looking at it, it's hard to see how your sail went up as far as it did before it got hung up!

It's always a good feeling when you don't take a short-cut and are rewarded for it. Now you'll feel good about it when you're sailing, having given it all a "tune up."

One thing I'm still getting used to here is the fact that boats can go years between haul-outs (or rig inspections). One thing the frozen tundra of Lake Superior gives you is a guaranteed annual haul-out (although not everyone takes the mast down every year).

Rachel