Masthead Rig

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Masthead Rig

Postby jblumsden » Wed Jul 29, 2015 9:31 pm

Has anyone changed the forestay to allow for a masthead rigged jib vs. the standard fractional rig? I don't race my DS2 and the boat has a wicked weather helm which I cannot reduce to my satisfaction by adjusting the stay tension. Thanks.
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Re: Masthead Rig

Postby TIM WEBB » Wed Jul 29, 2015 10:01 pm

Not sure, but I think if you did that you'd need to add a backstay?

Have you checked all the other factors that lead to wx helm, like sail condition/trim, CB position, rudder blade down, etc.?
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Re: Masthead Rig

Postby jblumsden » Wed Jul 29, 2015 10:18 pm

Good advice re: backstay. CB is all the way down- have not tried intermediate positioning of the centerboard.
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Re: Masthead Rig

Postby willyhays » Wed Jul 29, 2015 11:12 pm

Have you tried adjusting the mast rake? Is your mast stepped on deck or through the deck? If it is through the deck, have you considered adjusting the mast step position?
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Re: Masthead Rig

Postby jblumsden » Thu Jul 30, 2015 10:22 am

I've not tried adjusting the mast step. My boat has the mast stepped on deck with a compression post underneath. I am not familiar enough with all of the different configurations of DSs to know whether or not my arrangement is of the original design or a later modification but given the lack of old fastener holes in the deck, I think it is original. It certainly is feasible to move the location of the on-deck mast step a small distance. Would I move it forward or aft?

The reason I am considering changing the forestay at all is the fact that in a Cape Dory 25 I once owned, I had success in adding a second jib, making a sloop into a cutter and already have all of the parts needed (except a jib with longer luff) for making the modification I am considering. The old CD also had extreme weather helm and ended up with a nicely balanced helm with the second jib with the wind forward of the beam. I admit to not putting in a reef as soon as I should...
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Re: Masthead Rig

Postby rnlivingston » Thu Jul 30, 2015 11:51 am

While your idea of a masthead rig would probably solve your problem it would probably overpower you in strong winds. The couple of times I've capsized a Daysailer, it was the jib that pulled me over. When you have weather helm, it indicates you have too much power aft. By raking your mast forward, you move the power forward minimizing weather helm. Hopefully you have turnbuckles on your stays and you have enough adjustment room to loosen the side stays and tighten the head stay. Moving the mast step is a second option, but may be difficult on your boat. Let us know how you make out.
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Re: Masthead Rig

Postby jblumsden » Thu Jul 30, 2015 12:09 pm

Thank you for your input. I do have a little more (but not much) threads to take up on the forestay. I'm headed out for a sail shortly and will make the adjustment and see what happens. By comparison to an object ashore- a huge cement silo- my mast is currently dead vertical. I am new to the world of Day Sailers and am just finding my way around rigging adjustments. I think that it doesn't help that the existing sails are old and in fairly poor condition. In my previous boat, I noticed a great improvement in sailing performance with new sails. Alas, my ex-wife seemed to want the CD more than I did.
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Re: Masthead Rig

Postby willyhays » Thu Jul 30, 2015 1:09 pm

In the interest of touching on all bases, but at the risk of stating the obvious, are you sailing the boat relatively flat? Could it be possible that your excessive weather helm is a product of excessive heel rather than a poorly balanced boat?
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Re: Masthead Rig

Postby rnlivingston » Thu Jul 30, 2015 1:19 pm

Blown out old sails will certainly move the power pocket back. A Cunningham would help that, but only minimally. Although I sail with a pricy set of North racing sails, my son just bought a set of sails from Intensity. For $500.00, I was very impressed by the quality and how they perform on his Daysailer. Of course now I have to worry about him beating me when we race together.
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Re: Masthead Rig

Postby jblumsden » Thu Jul 30, 2015 6:01 pm

Thanks to all for the good advice. In today's sail, I used the drifter as the headsail (for the first time in this boat) and the helm seemed better-balanced to me. The boat was a little overpowered for the wind conditions however I had a heavy crew to hold the boat relatively flat. I was able to change the mast rake only slightly. The rigging screws are all nearly at their shortest extent which I expect is due to the stretch of the old standing rigging- another winter project, along with a new suit of sails if I can swing it financially.

Collectively, you all have convinced me not to rush into moving the top of the forestay though I still wonder if a short-footed jib extending to the masthead would add power through the slot effect without leading to an early capsize. I have heeled the boat sufficiently to get ALOT of water in the cockpit and was very pleased with how the boat reacts to this condition- a Lightning would have you swimming in the same situation. The architect got it right way back in '59.
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Re: Masthead Rig

Postby GreenLake » Thu Jul 30, 2015 7:27 pm

That would be Uffa Fox in '59.

The mast should probably not be dead vertical. That sounds like your mast is stepped too far back. A slight mast rake aft would be normal, and if you can't achieve this any other way, you may need to move the mast step forward a bit.

But as others have alluded to, you'd want to rule out any other issues, like trim. You aren't trimming your jib for example too loose and the main too tight? Or for your CB - you are sure that it comes down vertical when you think it is (and not have it angle forward a bit?). Finally, if your rudder isn't fully down, that can make it harder to steer and feels like weather helm.

At some points, your sails will be blown. Think of them as consumables (which they are, in the same way as brakes on a car -- at regular intervals much shorter than the life of the boat the sails will have reached the end of their lifetime measured not in calendar years, but hours of usage time strength of wind).

Investing in a new set of sails should come before trying to re-architect the sailplan. If you get a new set, and still can't trim them to balance the boat, then it's time to look at mast steps or similar changes.
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Re: Masthead Rig

Postby UCanoe_2 » Fri Jul 31, 2015 9:58 am

To adjust mast rake, the North Sails rigging guide http://www.onedesign.com/SailFaster/TuningGuides/tabid/19139/language/en-US/Default.aspx
recommends attaching a tape measure to your main halyard and running it up the mast. The measurement from the masthead to the center of the transom should be 25' +/- 1". This worked for me when I re-rigged, and I did not need any further adjustment to balance the boat, YMMV. Make sure your mast is plumb relative to the boat by measuring from masthead to chainplates; the measurements should be equal port and starboard.
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