Twin headsails for trade wind sailing

[malbert73]

Originally Posted by Cpt Pat

... Steering a fin-keeled boat downwind always reminds me of landing a tailwheel airplane: it continually wants to swap ends and go stern-first. Like tailwheel airplanes, it's nice to have an effective rudder -- but it's easier not to need it. One learns to be very good at tap-dancing on the rudder pedals, or wearing out your elbow on the wheel. Except, when landing a "taildragger" the experience only lasts a few seconds. On a fin keeled boat, it persists for the entire voyage.


Inherent instability. Like balancing a broom by the end of its handle.


Just my experience...

There are well balanced easy to steer boats with fin and full keels. But your experience with fin keel boats is very different than mine. My T40 is much more directionally stable than my prior Luders 33. Both designed by excellent designers (S&S and Luders respectively)

[RaymondR]

As a single hander one of the advantages I have found with flying a genoa and genaker as twin head sails is that I can screen the genaker in the lee of the genoa and retrieve it under the foot of the genoa, much less of a struggle that way.

[billknny]

Originally Posted by RaymondR

As a single hander one of the advantages I have found with flying a genoa and genaker as twin head sails is that I can screen the genaker in the lee of the genoa and retrieve it under the foot of the genoa, much less of a struggle that way.

Another option is to go the other way, and gybe the genaker across the foretriangle, and let it lie flat on the windward side of the genoa. It slides down nice and easy and under full control. A little bit more tugging needed if the sails are really wet from heavy rain, but still a piece of cake.

We do it either way, and don't have strong feelings about which is easier. Usually it depends on if we are going to leave the genoa clew on the pole or not.

[SY Kelpie]

Just a thought about halyards.
I realise you can't just stick a halyard on each sail, because you wouldn't then be able to furl them. And that the easy answer is to just use a single halyard, but that makes it a little harder to revert to a conventional sailplan.

So could the second genoa be hoisted on an endless halyard, using a block shackled to the top swivel? The whole halyard would have to furl away inside along with the sails. The second genoa would likely need to be a little shorter in the luff. Applying halyard tension might take a bit of lateral thinking.

[Tudorsailor]

Nice video shows how a UK sailmaker would set up twin headsail
https://youtu.be/G8LmSX-vEys

Tudorsailor

[moseriw]

The roll seems to be a big problem but there may be a solution:

https://www.parasailor.com/home-2439.html

[smacksman]

The twizzle rig is for trade wind sailing - you set the rig and leave it up for days or weeks. Easy rig change for windward/reaching doesn't come into it.
Not using the main and the consequent chafe on the shrouds/crosstrees is a good point.
The ability for one crew to reef at night from the cockpit is a good point.
The twizzle rig is for cruising not racing - peace not glory.
I put the above videos up on my website/Youtube 15 years ago - I am happy to answer questions if I can.
Roger

[muhiudeen]

Team,

You should invest in another wisker pole, an adjustable one so you can use it for other things, like as a awing or dinghy hoist, or pull batteries out of the boat!
Then you should read up about the Twizzle, look at

https://www.youtube.com/watch?v=sy53gIOrE40

You can make the connecting piece yourself with an old mooring line. Make sure that you keep the poles head forward of the connecting piece. If you have a modern rollerfurling the luff should have 2 groves, so you can raise 2 headsails on one rollerfurling system. Then to reef, just furl. Don't fly the main, and let the Twizzle rig reduce the rolling. Put the Bimini up and enjoy that ride.

Fair winds.

[admiral 31]

Rolling with the Hiscocks

https://www.youtube.com/watch?v=g_RHHIV4u1k

10:36 on for about a minute or so



32 degrees either way at 2 second intervals, ouch

[sanibel sailor]

How sophisticated does the twizzle rig pole joining gear have to be? Would a simple metal ring work in a 35 footer?

[Singularity]

Originally Posted by sanibel sailor

How sophisticated does the twizzle rig pole joining gear have to be? Would a simple metal ring work in a 35 footer?

Explained in the previous linked video; this starts at the pertinent point on the subjected of joining gear/universal joint. A "simple" rope knot was advised; easy to fabricate with materials on board:
https://youtu.be/inpr3r3Fw18?t=538

[Cpt Pat]

Originally Posted by malbert73

There are well balanced easy to steer boats with fin and full keels. But your experience with fin keel boats is very different than mine. My T40 is much more directionally stable than my prior Luders 33. Both designed by excellent designers (S&S and Luders respectively)

My experience may be biased by doing return voyage deliveries, where I have sometimes been hired to return the worst-behaved boats. I suspect my customers may be thinking: "Oh no. We don't want to sail our boat back (insert point-of-sail here). And don't tell him about the grounding/bent rudder shaft/loose keel bolts/leaking through hulls/delaminating rudder/failing wheel steering."

So I've ended up with what may be an eclectic set of biased dislikes: "Fin keels are unstable underway and prone to leaking at the attachment points (or even falling off). Rudders not hung from a keel or skeg are fragile. Beamy boats roll like a ball in a seaway. Through hulls are evil." Etc. After a few years of that experience, I chose for my own little boat a full keel with encapsulated ballast, a keel hung solid mahogany rudder, and I eliminated all through hulls except the cockpit drains and rudder shaft that's steered by a tiller. Maybe it's just me.

I've never been hired to sail either of the two boats you list above. Maybe because the skippers of those models wouldn't hire someone to sail them back.

[Cpt Pat]

P.S. After reviewing my post above, I should explain what I mean by my observation that at least some fin keeled boats are "unstable." Some have a tendency to continually fall off course in continual "S turn" oscillations. In aerodynamics, this is called a phugoid oscillation (https://en.wikipedia.org/wiki/Phugoid). In airplanes, it occurs in pitch. In boats, since the "foils" (keel and rudders) are vertical instead of horizontal, it occurs in yaw. Both effects are related to the behavior of foils: the wings on airplanes, a foil rudder and keel on boats.

Then there's disturbance in the waterflow impacting the rudder. Engineers designing an airplane go to great lengths to design the airframe so the rudder is in "clean" undisturbed airflow. The design of a fin keeled boat can place the rudder in the disturbed waterflow of the keel located forward. A foil-shaped rudder that depends on hydrodynamic lift - instead of a traditional rudder that is merely a water-deflecting flap - is much more sensitive to both velocity and disturbance because small changes in angle-of-attack can have large effects on foils. (Also: foils can stall - flaps don't.) All that combined can result in a "tender" boat that resists a straight course and requires constant rudder adjustment to remain on course. I suppose not all fin keeled boats, but most in my experience.

That may be an acceptable performance versus behavior trade-off for many. All boats embody compromises. But I consider course keeping behavior, where I can balance sails and let go of the tiller, to be more important than a few 10ths of knots improvement. Making 10 "S" turns per mile gets mighty old mighty fast. And once up to hull speed, all keel forms are pretty much equal.

[moseriw]

btw. the parasail is designed for tradewinds and up to 35 knots. Whereas commen spinnakers go only upto 20 knots at max.

[Jim Cate]

Originally Posted by moseriw

btw. the parasail is designed for tradewinds and up to 35 knots. Whereas commen spinnakers go only upto 20 knots at max.

Not true at all. "Commen" (sic) spinnakers are commonly used at wind strengths far greater than 20 knots. This can be observed almost any summer weekend day on SF Bay, where racers carry kites well up into the 30s. That's why kites are made in 0.5, 0.75, 1.0, 1.5 and even heavier weight cloth.

I dunno about the parasail... never have actually seen one in use in any wind strength. Wonder why they are so uncommon?

Jim