A-Frame Mast

Thanks for saving the pics for us! What a collection of neat ideas!

Not strictly a lateen - more of a leg o’ mutton sail, considering the sprit and near vertical mast.I would worry about the wear on the mainsail through the mid-boom support ring, if it is a ring, and if it is a ring then how can the sail pass through it for reefing/sailing? Must have a sail gap with rollers. Pity the original site has gone.

 

The 'mast/luff' on which the sail rolls is not anything near vertical (pic). But it's also not as much angled as a traditional lateen.


About the 'ring'... it looks to me like somthing like this... (example)

Don't know if I used the correct names when I said.. ‘‘The lateen is hanging in the A-frame in with what seems to be a reefing claw.’’

About the wear; an extra layer of cloth on both sides of the sail where the rollers go..? and bigger diameter and wider rollers..? (see twin rollers for a start)


I think this is a leg of mutton rig... (pic source)

Calidris' main looks more like a lateen to me.. with the addition of a roller reefing system and a swiveling boom at the bottom to set it better to the wind and makes it easier to tack then a traditional lateen.

Yes, a lot of neat ideas in it

Cheers,
Angel

 

Yes, I think you are right about the ring, whatever it is called. It must get a lot of strain put on it in a breeze.

The sail in your last image is a type of leg of mutton as you say, but it is more commonly three-sided without the club at the end of the sprit. The reefing system is not relevant to the type of sail IMHO. I've never seen or heard of a lateen with a sprit whereas LOM's usually have one. The loose-footed three sided sails I have seen are more or less horizontal along the foot - presumably to keep the clew low - not a problem with a sprit.

I found this definition of a lateen "A triangular sail, extended by a long yard, which is slung at about one fourth of its length from the lower end, to a low mast, this end being brought down at the tack, while the other end is elevated at an angle or about forty-five degrees ... Some lateen sails have also a boom on the lower side"

That last bit is getting awful close to a crab claw. Perhaps we should split the difference and call it a calidris sail ... it's unique enough to have its own name.

 

Right, a Calidris sail it is

Cheers,
Angel

 

The http://www.boatdesign.net/forums/boat-design/mastless-crab-claw-37083.html#post449255 discussion is related

 

Just for info... the discussion about Calidris' rig continues in the ‘‘Reefing a lanteen sail’’ thread from post #58 and beyond...

Cheers,
Angel

 

Try this thread http://www.boatdesign.net/forums/boat-design/wishbone-sailing-rig-1999.html
Lots of similar ideas.

 

Jean Merrien a French sailor and designer in the 1960 built several cruisers with A frames masts and two keel.
He was quite successful for a while with the A frames.
I find it odd and not very appealing.
but it's me
Lister

 

Good find Angelique.

I added a link to your posting here to this much bigger discussion of A-frame related discussions:
http://www.boatdesign.net/forums/boat-design/wishbone-sailing-rig-1999-13.html#post489186

Edited: Opps, 'upchurchmr' bet me to it with the cross reference. I hadn't got to the second page of this discussion before I made my posting

 

Well it's to your credit for making a post and posting the link there which makes Calidris a widespread topic on the forum, she and her rig are in three threads now, and all on topic, so lets wait for a spin off . .

Cheers,
Angel

 

Angel,

Calidris was a very limited part of the link posted by Brian and myself. And it applies to this thread, so why should we wait? And for What? Did you look at the whole linK? there are multiple different boats in the link. the only thing I didn't like is the people who say an A frame is terrible, and those who say it isn't with no facts. Fortunately there are some who have enough detail to lead one to make their own decision.

Like the people interested in this thread.

Do you not like Calidris?

 

I wasn't talking about the links posted here (although they are very welcome too, so thanks ) but was talking about the links posted there . . . . (note the word ‘‘there’’ in the post you replied to)

The waiting part is for the ones, like myself, who aren't experimenting themselfs but are very intrested in the results of what others will come up with, I'm very greatful they share their knowledge and what they are doing

Yes, so I've seen.

I like the whole concept of Calidris and I would like to know if the reefing claw handles the strain well that's put on it in a breeze and about the wear of the sail in the claw.



Cheers,
Angel

 

I am very interested in this rig, as it seems like it can be built quite cheaply and looks easy enough to handle for extended coastal cruising. This is the only info i can find on this rig! I would like to convert my 1971 Columbia mkII 26 to such a rig. Do you think it is possible to make a strong enough a frame from. 10 ft long 2 in dia conduit with octaganol wood spars inside? How long of a yard would I have to have ect. Any info that can be useful in designing a rig like this for a specific boat would be fantastic. One key detail that needs determined is where to place the a frame. Thanks for any help.

 

Wood inside the aluminum frame is essentially useless, just added weight and cost.
You also need to know the gauge of the tubes before anything can be decided.
You need an engineer to help you.
Probably a Naval Architect.

 

Welcome to the forum.

Agreed, you'll need some design work performed. A skilled engineer, designer or NA can get it done for you and shouldn't be terribly costly, if you select a relatively unknown designer, or possibly a student, well along in their studies.

As far as cheaply built, well I doubt it'll be less than a more conventional rig. For example the sails you currently have will not be well sized, so you'll need a new main and a mizzen, plus you'll probably want a staysail and possibly a couple of mains, to suit different wind strengths. This doesn't count the cost of the A frame setup and it's associated standing rig, nor a well balanced design to fit your Columbia 26.