Why don't catamarans have boom vangs?

[StuM]

Originally Posted by fxykty

Vang and Kicker are synonyms - they both mean the same thing. Different places use different words.

I originally learnt it as a "kicking strap", but that was probably before the advent of solid vangs

[markiobe]

Originally Posted by AKA-None

Ok so in this thread I see people referring to a vang to hold the boom up but I always thought a kicker held the boom up and a vang pulled the boom down
But a single device may do both
Please correct me if I’m mistaken

Just for final clarity and to add to fxykty's wise words; the system called variously kicking strap/kicker/vang is for exerting downward force on the boom, only.

The fact that a small percentage of them also hold up the boom is totally incidental. An object that's only function is to hold the boom up is NOT a kicking strap/kicker/vang regardless of the fact that it might resemble one.

[markiobe]

Originally Posted by StuM

I originally learnt it as a "kicking strap", but that was probably before the advent of solid vangs

It's more a geographic difference rather than a descriptive one. In the UK I learned kicking strap/kicker, in the US and Australia they use vang (I think). You can have a vang or kicker that is either 'soft' with various cascading blocks or hard which has some rigid component to it.

[StuM]

Originally Posted by markiobe

An object that's only function is to hold the boom up is NOT a kicking strap/kicker/vang

Not to be confused with a boomkicker then
https://en.wikipedia.org/wiki/Boomkicker

[StuM]

Originally Posted by markiobe

Just for final clarity and to add to fxykty's wise words; the system called variously kicking strap/kicker/vang is for exerting downward force on the boom, only.

Maybe you should explain that to the manufacturers of the Boom Kicker, Bamar Rigid Vang, US Spars/Z Spar Vang, Selden Rod Kicker, Hall Spars Quick Vang, Vang Master, and Sparcraft Vang to name a few.


I'm sure they will appreciate your correction.

[markiobe]

Originally Posted by StuM

Not to be confused with a boomkicker then
https://en.wikipedia.org/wiki/Boomkicker

Originally Posted by StuM

Maybe you should explain that to the manufacturers of the Boom Kicker, Bamar Rigid Vang, US Spars/Z Spar Vang, Selden Rod Kicker, Hall Spars Quick Vang, Vang Master, and Sparcraft Vang to name a few.


I'm sure they will appreciate your correction.

FFS!! IF PEOPLE KEEP CHANGING THE DEFINITION OF THINGS, HOW IS ANYONE SUPPOSED TO KNOW WHAT ANYTHING MEANS!!

Ok in which case I'll modify my words: As far as I'm concerned, and as far as ANYONE was concerned until... (insert your date here), a kicker/vang is a system to exert a downward force on a boom and certainly what I meant when starting this post.

Full stop.
Period.
Nuffink else to say.
Done.

[nightowle]

BTW is it traveller or traveler?[/QUOTE]

Traveller if you're British, traveler if you're in N. America. Can't be helped.

[fxykty]

Originally Posted by catsketcher

Nathan Stanton bought Songlines - 45 or 48ft long and probably the most beautiful cat I ever saw. My first time I saw her was watching her builder/skipper (Neville Lloyd) gybe her down the Brisbane river with a flick of his wrist to get the main to gybe - on a large and very nice cat. Last I saw of her was in Brisbane.



Nathan then designed the Freeflow cats - I have included a link below. He altered Neville's wishbone idea with the addition of a boom. This gives ulitmate control of the sail shape. You can see in the shots how the sail can be eased off and still be well vanged.



FreeFlow Catamarans



I would recommend a verson of this setup rather than the wishbone itself - although it is more hassle to build. The boom could be a simple tube - I will probably use a sailboard mast if I upgrade my wishbone. I will even use the mast base and universal. It only acts in compression and can be very light for my use.



As for the wishbone riding up - like a sailboard sail, the foot provides the tension to stop the clew rising up. In my main the sailmaker sewed a length of spectra into the foot - so it takes the tension rather than the cloth. The sail swings in and out like a gate - the tension the wishbone places on the sail is dictated by the tackle at the front end of the wishbone - I call it the snotter tackle.

Songlines is moored in Manly Harbour on Moreton Bay - she is just opposite our berth. Very nice looking boat and striking with the red hulls. I haven’t seen anyone on her or her going out unfortunately - I’m very keen to go for a sail on her.

[catsketcher]

Gday Fxykty

Would you be able to take photos of Songlines and her wishbone? I am pretty sure Nathan modified it and I would like to know what he did.

She is the only cat I would trade my boat for - she is a real gem (and she has a wishbone too!)

Cheers

Phil

[44'cruisingcat]

The reason we don't need a vang is because when sailing very deep or DDW, we run a preventer from the boom end, through a block mounted wide on deck, onto a winch. All the sail twist control you need, easy, with the bonus of preventing accidental gybes.
For any other deep point of sail, the wide traveller does the job.

[Sos]

Welcome back 44

[capn_billl]

To avoid confusion in the future, all sailing term dictionaries will be amended as follows.

A boomvang is designed to exert a downward force, a boom kicker is designed to exert an upward force.

A rigid vang can do both.

Using these terms interchangeably makes zero sense.

That's why we use words to communicate.

If we cannot agree on word definitions then communication, especially over the internet is impossible.

[fxykty]

Originally Posted by catsketcher

Gday Fxykty



Would you be able to take photos of Songlines and her wishbone? I am pretty sure Nathan modified it and I would like to know what he did.



She is the only cat I would trade my boat for - she is a real gem (and she has a wishbone too!)



Cheers



Phil

[Stephen Ditmore]

Would love to see more about your custom multihull build, Markiobe! Also more about above-the-boom vangs, including what Google search term to use to see more about various arrangements. If one doesn't have or want a 2 sided pocket in the main, I'm thinking something akin to a mini-wishbone boom except probably a simple rectangle with a little rounding at the corners just to avoid sharp edges. This would come slightly beyond both mast and boom with "soft" rope connections & control down the front of the mast. Yes there could be a bolt through the boom, but drilling the boom might weaken it in exactly the wrong place.

I'm also intrigued by boomless catamaran mains (are America's Cup foilers going to this)? If one has a clean & workable traveller control arrangement perhaps a boom becomes unnecessary - a batten along the foot will suffice.
And if the latest innovation in sail making is a "structured luff" how about a "structured foot"?

I had an early catapult catamaran with no halyard that had a wishbone boom hinged in the middle with a control line that passed through a grommet in the middle of the sail. That was an interesting arrangement.

The Italian AC boat with the boom under the deck and other things I've seen lately cause me to suggest: what if the boom we're in the coachroof? By 'in", I mean the upper coach roof is solar panels on beams as necessary to support them. The boom swings under the solar panels & beams. Perhaps the beams run fore & aft so the structure supporting the traveller at the back is also what the beams land on (perhaps the boom swings under that as well, so the boom is connected to it by a car on top of the boom). Then there is a liner under the boom that serves various purposes including keeping the hot air under the solar panels out of the crew/passenger enclosure.

[Stephen Ditmore]

Originally Posted by markiobe

Phil kindly took the time to chat with me about his rig and, although he thinks its fantastic, one of the ideas to improve on his layout was to have the aft end of the wishbone attach to a traditional boom via a short track. That way you could have a line running through a block system pulling aft, then forwards to the mast to be led wherever. Pulling the line would push the wishbone down, tensioning the leech. It would provide an elegant way to adjust leech tension.

One of his other points was that nowadays you'd make the wishbone out of carbon to ensure that you have the stiffness to not distort under the load.

Seems like both these ideas could be simplified. Take a look at https://www.pdracer.com/sail/mutton/. Either a wishbone or a simple leg-o-mutton sprit can be adjusted with a line through a block at the front of the mast - a "snotter" - no need to worry about outhauls at the clew. Also, yeah, carbon is stiffer, but why start with a prebent wishbone? If a simple sprit bothers you because the sail lies against it on one tack, why not make your "wishbone" a simple trapezoid? The front will be in bending and the long sides will be in compression, so the parts that are in simple compression will initially be straight ('in column' except for having to support their own weight).