Re: [bolger] Poor Man's Ljungsrom

From Bente Støa
Teoraticly, thise boats are lightweighted, so smaller sail may work better than full sail?

2014-06-06 11:03 GMT+02:00a-kve2@...[bolger]<bolger@yahoogroups.com>:

Stavanger, 6th June 2014

When I made that little simplified version of the Ljungstrøm rig for a friend’s boat, it was because his wife asked for the simplest, safest and most fuss-free rig I could think of. With its easy setting up, reefing and furling, and with only one running line, the sheet, I think I came pretty close. The rig was in use for over 20 years, until they parted with the boat. The rig’s good upwind performance came as a surprising bonus.
(I repeat the link to that story:http://goo.gl/Nu6nOu )

I agree with Bolger in some of his critics when it comes to the full size Lj-rig for bigger boats. The main problem, in my view, is the scale factor: As boats grow, their displacement tends to grow faster than the sail area. A decent sail area for a 3-ton LJ-rigged boat would call for a very tall and well-engineered mast and serious mechanics to rotate it.

The unpretentious little rig for that rowboat however was easy to make and use. The full-length battens (wood) were simply added to get maximum sail area with the shortest possible mast. I don’t claim it to be a world beater which will fit every boat.

Now, it is not easy to find any rig’s strong and weak sides at the keyboard, so I suggest you make one and try it yourselves.

Cheers and good luck!
Arne Kverneland

PS:
BTW, most of my rig fiddling the last 20+ years has been done on junkrigs. Here is a link to a page with some write-ups about that subject.

http://www.junkrigassociation.org/arne

http://goo.gl/

Stavanger, 6th June 2014

When I made that little simplified version of the Ljungstrøm rig for a friend’s boat, it was because his wife asked for the simplest, safest and most fuss-free rig I could think of. With its easy setting up, reefing and furling, and with only one running line, the sheet, I think I came pretty close. The rig was in use for over 20 years, until they parted with the boat. The rig’s good upwind performance came as a surprising bonus.

(I repeat the link to that story:http://goo.gl/Nu6nOu )

I agree with Bolger in some of his critics when it comes to the full size Lj-rig for bigger boats. The main problem, in my view, is the scale factor: As boats grow, their displacement tends to grow faster than the sail area. A decent sail area for a 3-ton LJ-rigged boat would call for a very tall and well-engineered mast and serious mechanics to rotate it.

The unpretentious little rig for that rowboat however was easy to make and use. The full-length battens (wood) were simply added to get maximum sail area with the shortest possible mast. I don’t claim it to be a world beater which will fit every boat.

Now, it is not easy to find any rig’s strong and weak sides at the keyboard, so I suggest you make one and try it yourselves.

Cheers and good luck!

Arne Kverneland

PS:

BTW, most of my rig fiddling the last 20+ years has been done on junkrigs. Here is a link to a page with some write-ups about that subject.

http://www.junkrigassociation.org/arne

http://goo.gl/

They have been hundreds of experimentations of this simplified Ljungström rig : http://www.nauticaltrek.com/12771-2-voiles-ferlables-sur-mats-non-haubanes-montaubin-hobie-raptor-etc (or http://x2t.com/308492 , all in French, sorry), and most of them seem to work fine.

Le Jeudi 5 juin 2014 23h02, "'John Trussell' jtrussell2@... [bolger]" <bolger@yahoogroups.com> a écrit :

I have no experience with either rig.

PCB wrote about both rigs in his book 100 Small Boat rigs. He points out that it is difficult to cut a roller reefing main sail so that it sets well when even partially reefed, that there are sheeting issues, and that the sail shape doesn’t work when opened unless some sort of spar is attached to hold them open. He also states that the dipping lug is the most powerful and close winded of all one sail boats. Anyone contemplating swapping rigs around should read PCB’s book. I would also be inclined to experiment on small boats and a PDR might be the perfect tese bed!

Have fun.

JohnT

From:bolger@yahoogroups.com [mailto: bolger@yahoogroups.com ]
Sent:Thursday, June 05, 2014 4:40 PM
To:bolger@yahoogroups.com
Subject:[bolger] Poor Man's Ljungsrom