Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
Took the boat out for a first shakedown sail after purchasing her last Sept. All went well, especially for how neglected she had been over the last 4 years. Lowering the mainsail didn't seem to have any issues on that sail. I went out last weekend to do some work and attempted to raise the main, no luck. Pulling down on halyard, jammed after about 6", tried to pull back down on sail side of halyard, no movement. Looking at the masthead with binoculars it appears that the halyard jumped the aft sheave and has jammed between that and casting. so this weekend will find me pulling boat to drop mast and correct. Having been in aviation maintenance for many years rigging control cables, there is always keeper pins at the pulleys to keep cables from jumping off. I don't recall seeing any kind of keeper to prevent line from jumping off sheave like mine has. I replaced cable sheaves this spring as well as halyard line. I believe when I have mast lowered this weekend, I will install some sort of through pin/bolt to prevent this in the future. This seems like it could have turned into a rather large issue if it happened with mainsail raised. Anyone had any similar experiences?
I do not recall something like this being reported except in the case of a sheave disintegrating. I have rope halyards internal to the mast and there isn't clearance for the line to jump the sheave and jam. Wire halyards/external are probably a different story.
1988 C25 Wing Keel Std Rig Tohatsu 9.9 Tiller Steering and 2003 C250 Wing Keel Std Rig Inboard Diesel Wheel Steering
Hi Randy, If you have a C-25 with external halyards (usually rope to wire - with the wire riding on the mast cap sheaves) there should, in fact, be an aluminum spacer that would be placed on the center-line between port and starboard sheaves (two forward and two aft in the mast cap. If the spacer is missing, the cable can jump off a sheave and jam between the sheave and the aluminum cap casting. Bill Holcomb - C25 Snickerdoodle #4839
That plate is what he is referring to. Take photos when the mast comes down before doing anything else. I can't visualize enough space for a line to come off in that casting. I have a 5/16" main and a 3/8" genoa halyard. The 3/8 halyard is a close fit until it is in place. The 1/4 is easier to thread but has never jumped off and no space to wedge in. I'll get a couple of photos tomorrow..
Dave B. aboard Pearl 1982 TR/SK/Trad. #3399 Lake Erie/Florida Panhandle
Hi Randy, If you have a C-25 with external halyards (usually rope to wire - with the wire riding on the mast cap sheaves) there should, in fact, be an aluminum spacer that would be placed on the center-line between port and starboard sheaves (two forward and two aft in the mast cap. If the spacer is missing, the cable can jump off a sheave and jam between the sheave and the aluminum cap casting. Bill Holcomb - C25 Snickerdoodle #4839
The wire halyard jumped off the sheave and jammed between the spacer and the cap casting, as Bill described, even though the aluminum spacer was in place on my boat. The easy fix for me was to buy a plastic "for sale" or "no trespassing" sign from a hardware store and make a plastic spacer to fill that space, so that there's no room for the wire halyard to get stuck in.
Steve Milby J/24 "Captiva Wind" previously C&C 35, Cal 25, C25 TR/FK, C22 Past Commodore
Dave, the photos would be greatly appreciated. Will take photos before correcting the jam to share. It is looking like a Sunday project. I am starting to think that I have may have caused this myself. I have a roller furler so have no jib halyard running over mast cap. When I replaced sheaves this spring, I only put in 2, one forward and 1 aft, which if I remember right is what the PO had installed, with apparently no issues. I also switched from 3/8" main halyard to 5/16". I am thinking that smaller diameter was able to jump the sheave where the 3/8 wouldn't. When it goes back up, it will have 4 sheaves in the mast cap to fill the space. Chalk it up to experience, best education there is!
Hi Randy, Yes, I was talking about the metal plate between the sheaves. With all rope halyards, I am wondering if the sheaves that were designed for wire have been replaced with sheaves designed for rope???? If not, the groove in the sheave will not hold the rope properly and the rope could easily have been pulled off of one side or the other. The rope cannot compress much - - but while pulling hard to raise the sail, the rope could have been pulled down between the side of the sheave and the casting wall or between the sheave and the metal plate if it's still in place. The easy solution to the problem is to take the mast down and look - - even thought doing this seems to take three men and a boy. If the sheaves are for wire, replace them with the same size for rope. Bill Holcomb - - C25 Snickerdoodle #4839 PS - When my original plastic sheaves died and started to fall apart, I went to a local metal machine shop and had four new sheaves machined out of bronze. I'm pretty sure that the "new" sheaves will last as long as the boat.
Thanks everyone for the input on this. Dropped the mast over the weekend and found the jam was from having only 2 sheaves in the mast cap, allowing the plate to flop around and line to jump off and jam between sheave and plate. I had replaced the sheaves over the winter and only put the 2 in, so it's all on me. No better teacher than experience.
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.