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  #1  
Old 04-13-2007, 03:41 AM
Andrew Craig-Bennett Andrew Craig-Bennett is offline
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Join Date: Apr 2007
Posts: 12
Default Halyard for a Wykeham Martin furling jib on a 37ft gaff cutter's bowsprit

First, let me describe the set up that we have had for many years now: A three strand dacron halyard goes from a pinrail on the port side of the deck to a single block on a strop on the mast, down to a single block at the head of the jib which is shackled to the top fitting of a Size 4 Wykeham Martin's gear, thence to another single block on the mast and thence, via a swivel, to a luff tackle purchase on the starboard side of the deck. The jib, with the furling drum of the W/M gear, is on a ring traveller on the bowsprit.

This all works reasonably well (I don't expect to achieve a ruler straight jib luff!) but over time the halyard twists up and we get a frap up; a half hour spent on the mooring milking the turns out of the rope clears it again.

Would I do better:

a) with the same set up but with braided rope?

b) with a wire halyard and a small winch?
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  #2  
Old 04-13-2007, 10:51 AM
Amgine
 
Posts: n/a
Default There are two issues

The furler, and the luff tensioning system.

You know the system you have is not going to be efficient with a furler. It's a very good system for a hank or wire luff sail which comes down when you're not using it. Due to the twisting force the W/M gear is going to generate no matter what you do, you will probably develop twist in the halyard. Everything about your rig, other than the W/M, is safe and simple operation. So my first and strongest suggestion would be to get rid of the W/M, take the sail down when you don't want it out there.

If you really want the furler, the next suggestion would be to place a permanent stay to the cranse. If you're leaving the sail up anyway, and the bowsprit is not rendering, there is little benefit to having the halyard/luff tensioning system while there are drawbacks such as weight and complication aloft.

If you specifically want to work with the gear and rig already in place, by all means move to braided low-stretch halyard. I would not suggest going to wire with a winch, in part because that's more cost and complication than just setting a permanent stay, and in part because it wouldn't suit the rig well while also introducing the opportunity cause yourself problems like cranking on the winch until the sail or the 'sprit gives way. If you go with braid, double check that swivel aloft cannot allow twisting. And don't spend for the hottest high-modulus ultra-low stretch rope, just a good quality; your boat cannot capitalize on the highest tech.

my $.02
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  #3  
Old 04-14-2007, 03:07 PM
Ian McColgin Ian McColgin is offline
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Join Date: Jun 2005
Location: Hyannis, MA
Posts: 368
Default

Ahoy Andrew,

I had this problem with Goblin, even though the halyard was two part wire-rope to a winch - no watch tackle. My first solution was to put a bale on the upper swivel so it would stay in one place vis-a-vis the stay. That was essential but not a complete solution. Remember, the twist was happening with a wire halyard. I think it comes in part from the luff wire and gets translated into the halyard.

What really helped was to get a good seperation at the mast between the fixed part of the halyard (the part to the watch tackle on your rig) and the hoist that went through a block and down to the winch on the mast.

From your description I cannot tell if on your boat the two parts are opposite each other, port and starboard on the mast. All the way out so that the halyard passes through a non-swiveling block that's essentially athwartships might do it. On Goblin the peak was far enough from the soft eye at the top of the stay that I went for verticle seperation.

That did it.

G'luck

Ian
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