i wish to fit a 550 square foot asymmetric spinnaker to my carbon fibre mast,this would entail fixing a block on the aluminum mast top plate.Has anyone ever done this or have any comments, we sail on Lake Ontario and wind is hard to come by.
Dave Corcoran
Hello Dave,
Here are a two pictures of the mastheads on my original masts (main and forward, F39 schooner). You can see that stainless “U-bolts” are (how strange!) bolted though the masthead aluminum plates, on which a single, 360° swivel block was attached.
The spinnaker halyards were running internally, coming out at the upper end of the masts around 1 meter below the block, through a 10-15 cm slot, thus minimizing friction of cable on mast. The spare “mainsail” halyards are external to the masts.
Finally, the bound between the metal masthead and the actual carbon tube (1983) is unbreakable, although, hélas! I can’t say the same about the carbon sticks themselves! (See below, thanks to hurricane Jeanne). New masts were built in 2005 to original dimensions, but 35% lighter, in one section, as opposed to the original 2-sections masts made by TPI for this F39 (can’t say for the others).
Cheers
Alain
Wow. Without the word picture to accompany those shots I thought you had invented some kind of cantilever mast system for ducking bridges.
George
So what happened during hurricane Jean to break the masts?
– Geoff
A picture is worth thousand words:
The only boat to fall off its stands in the yard, Indian Town, Florida (+/- 300 sailboats) was Naïade.
I suspect that the masts entered in resonance given the strong winds and that the vibrations got the legs slipping away. No witness. I had no topping lift or halyard tightened on either mast to prevent vibration/amplification, bad bad thing with a self standing rig. The boat on the right was a steel trawler, on which the masts snapped.
The two masts were the only casualties in the assault. NOTHING else was damaged inside or outside the boat, not a scratch, nothing… This is a sturdy hull, no doubts.
As for the replacement masts, splendid job by Ted Van Dusen at Composite engineering in Boston (http://www.vandusenracingboats.com/). He used to make the masts of the latest generation of Nonsuch, and cooked Bruce Schwab’s Ocean Planet carbon fiber mast for the Vendée Globe in 2005 (almost a self standing rig!) (http://www.bruceschwab.com/). Looks like a giant fishing rod to me!
