Do you want to be informed on new Posts on this Thread? (members only)

Sail & Rigging - Bowsprit for Code 0
08 May 2014 - 16:06
#22
Post Reply
matteo45
Join Date: 23 October 2011
Posts: 154

Dear Rob,
iYour last pictures are most interesting , thank you very much. By means a modified pulpit you succeed both in operating with more ease around the forestay and you have an overhang of 36 cm only!
, The stemhead plate, portside extension, looks welded to the existing plate, I suppose that you had to disassemble all the forestay chainplate with its stdmhead, or was it possible to do this job on the boat with acceptable overheating of the fiberglass?
The pressure given from a code0 is really impressive and I feel that a much close tension on the luff may also happen when broaching with a genny!
I was thinking at a tube of 63 external gauge 3 mm sliding in a length of 30-40 cm of a 75 diameter tube fixed over the pin. Now I understand that this solution, with a longer overhang than yours, is too much underdimensioned.
Thank you for your hints, they are very helpful!
Matteo

11 May 2014 - 16:11
#23
Post Reply
matteosalamon
Join Date: 29 January 2007
Posts: 1022

Dear Matteo,

attached is a photo I shot yesterday of sailing Lolita with her new carbon bowsprit, unfortunately I couldn't take a pic of details, hope to do it next week end…!

Fair winds

matteo (38/067 Only You)
11 May 2014 - 22:04
#24
Post Reply
matteo45
Join Date: 23 October 2011
Posts: 154

Dear President, thank you for the picture, it might be good to know with more detail about the fixing of the bowsprit to the stemhead plate.
I can observe that, both in Lolita and in Sarabande, the pulpit has been ridesigned, eliminating the fore arch of the toprail of the pulpit. Lolita's bowsprit looks to have more length out, Sarabande has the lower arch flattened, too.
Anyway this is a very good solution, it allows, too, to get to the boat more easily from the bow. And, too, it allows, with fair weather, to sit at the bow and contemplate the sea, one of the great pleasures when cruising!
Thank you, Matteo!
Matteo grampus 47/016
15 May 2014 - 12:52
#25
Post Reply
matteosalamon
Join Date: 29 January 2007
Posts: 1022

Dear Matteo,

here you are, below are three pics of the carbon fiber Bowsprit which has been installed onboard Lolita (custom job done by Elio Borio in La Spezia), very clean and functional

Fair winds

matteo (38/067 Only You)
15 May 2014 - 23:31
#26
Post Reply
matteo45
Join Date: 23 October 2011
Posts: 154

Dear Matteo,
thank you very much for the pictures.
It is a very good solution and very tidy. It looks like the collar of the bowsprit having two welded pins connected to the holes of a plate fixed to the forestay chainplate or to its toggle.
Most probably it has been designed without diminishing the strength of the chainplate system.
Thank you very much as always,
Matteo, grampus 47/016

22 May 2014 - 22:48
#27
Post Reply
philippe
Join Date: 16 February 2007
Posts: 199

Dear Matteo,

I would like to know more about the white sprit of Lolita: the measurements and the weight. I also would like to get in touch with the provider.

Can you help, or should I write directly to Roberto?

Cheers//Philippe
(47/050)
23 May 2014 - 10:14
#28
Post Reply
matteosalamon
Join Date: 29 January 2007
Posts: 1022

Mon Cher Philippe,

here you are, this is Elio's address: elio.borio (at) fastwebnet.it I think he could give you all the details or build the same for you and ship it

Fair winds!

matteo (38/067 Only You)
23 May 2014 - 23:31
#29
Post Reply
philippe
Join Date: 16 February 2007
Posts: 199

Many thanks cher Matteo
//Philippe
23 January 2018 - 07:19
#30
Post Reply
Jankooistra
Join Date: 01 April 2007
Posts: 106

Dear All,

I intend to make a (more or less) similar construction as Lolita on my 38.

I remember an older thread of a stemfitting that was not strong enough for a similar arrangement.

Do you think the stemfitting on a 38 is strong enough for a carbon bowsprit for a code zero ? I think a code zero needs considerable more tension on the luff, so the load will be much more compared to a gennaker. 

Best regards,

Jan (38/110)
23 January 2018 - 16:34
#31
Post Reply
the professor
Join Date: 02 January 2008
Posts: 1547

Dear Jan

It is suggested the bowsprit is attached to the stemhead plate on the forward side of the bow, and not to the deck plate. The sprit aft end may also require local reinforcement of the deck depending on its length and position.
The halyard load in a Code 0 is about twice that of a gennaker, and your halyard winches and blocks can not take that. If you have the original Lewmar 43 winches their safe working load is about 900 kg.
Suggest you ask the sailmaker what halyard loads he expects for the Code 0.
The recommendation is to set up a 2 to 1 halyard for this, you need a halyard with  50% more length, an attachment point near the masthead for it, and a block with sufficient strength for attachment to the top of the Code 0.
 
Kind regards
Lars

 
23 January 2018 - 20:59
#32
Post Reply
Jankooistra
Join Date: 01 April 2007
Posts: 106

Dear Professor,

Thank you very much for your advice.

Do you mean that even with a 2:1 halyard the spinnaker halyard block and the block-outhaul on the masttop is not strong enough ?

best regards,

jan 
24 January 2018 - 08:29
#33
Post Reply
the professor
Join Date: 02 January 2008
Posts: 1547

Dear Jan

Spinnaker halyard loads are assumed to be smaller, you can see this in the sizing of the halyard winches, Lewmar 40 for spinnaker versus Lewmar 43 for genoa.
 
Kind regards
Lars
24 January 2018 - 09:07
#34
Post Reply
jankooistra
Join Date: 01 April 2007
Posts: 106

Dear Lars and other owners,

Yes I understand (I hope). But I thought that is the reason why you advise a 2:1 halyard. And with a 2:1 halyard, the load that was twice the load of a gennaker, should be half and equal to the load of the gennaker. Or do I misunderstand that part ?

And the fixed part of the spinnaker halyard must be connected to the mast. And most easy would be to use the spi-block outhaul for that. But then the outhaul must be strong enough for the total load of the 2:1 halyard. Or do you have an other solution for mounting the fixed part ?

If the spi-block and halyard winch cannot be used for the code zero, what would be the other options ? How did the other swan owners solve this issue ?

Best regards,

Jan
24 January 2018 - 12:15
#35
Post Reply
the professor
Join Date: 02 January 2008
Posts: 1547

Dear Jan

The early Code 0's required very high halyard loads, but you may also have a light weather reaching version in mind. These have appeared later, and need less halyard tension, about the same as your largest genoa, meaning you could possibly use your genoa halyard as is, but the spinnaker gear would need 2:1. Suggest you find out the actual loads.
 
There is usually a problem with Code 0's and masthead rigs - the halyard and forestay are too close together, and do not allow the head of the Code 0 to rotate freely. It is advisable to discuss this with the sailmaker.
Kind regards
Lars
26 January 2018 - 09:45
#36
Post Reply
the professor
Join Date: 02 January 2008
Posts: 1547

Dear Jan
Some mast builders have solved the halyard-stay-too-close-problem by adding a longer crane for the Code 0 halyard.
Kind regards
Lars
  • Threads : 1707
  • Posts : 10233
  • Members: 821
  • Online Members: 1