"Bowsprit"

[alan]

\"Bowsprit\"

I am looking for some bright ideas for a "bowsprit" which can be used when flying an asymetric or genoa-light type of sails. My boat is a Beneteau Oceanis 311. I would like to keep the anchor in place on the bow roller. At the moment I attach the tack of the sail to a convenient hole in the stemhead. I would ideally like to have the tack attachment about 50cm (or so) further foreward. I have an idea to attach an alluminium tube to one side of the stemhead fitting with the "weight" of the tube being supported on the base of the stemhead fitting - I have made a rough prototype from an old rigid vang part but have not been able to try it under sail yet. (Difficult to describe unless you can see the stemhead fitting which is conveniently slightly offset from centre.)

I would be interested to have any other ideas or in particular if there exists a commercial piece of kit for this purpose?? I don't want to make a hole in the hull/chain locker and do the job properly with a real bowsprit .......... I don't like making holes in the boat!!!

Thanks in advance.

Alan.
Nettuno, Italy.

<hr width=100% size=1>Alan Cloke

 

[alan]

Re: \"Bowsprit\"

O.K. then I'll answer my own question!
Just in case anyone reads this and are interested, after searching lots of web sites I have found two commercial bits of kit:
1. From www.hammax.se in Sweden which looks interesting as it can be adapted for most boats and is truly retractable and removeable. Costs around 450 Euro depending on mounting arrangements. However it looks a bit home-made-ish.

2. Frpm Sparcraft. However their website is not so good, and you cannot get a clear idea of how it mounts. However it looks neater than the one mentioned above but being a single pole arrangement it will have to be run out in the centre of the stem head which impedes the anchor and chain locker (on my boat).

If anybody else knows of any other sources then I'd really like to know.

Alan.
Nettuno, Italy.

<hr width=100% size=1>Alan Cloke

 

[boatless]

Re: \"Bowsprit\"

Alan, Hi

Doubt that many forum members have much experience of this. Haven't looked at the kit you mention, so can't comment. If you are going to use an ordinary assy, shouldn't be much of a problem. If contemplating a full on Code 0 at any point, then tube stiffness will need to be pretty high.

Quite a few Benny sailors frequent sailinganarchy.com/forums - but if you're not thick skinned don't go! Best to register and post in the registered section


<hr width=100% size=1>my opinion is complete rubbish, probably.

 

[Rich_F]

Re: \"Bowsprit\"

One thing I've seen on a Dehler is a ring-shaped fitting on the side of the pushpit, through which the spinnaker pole will fit. You slide te pole in, then clip the inboard end to a fitting on the deck. Instant bowsprit / battering ram!

I've not seen these for sale anywhere, though.

Rich

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[Talbot]

Re: \"Bowsprit\"

Cant answer the specifics, but would not even consider the use of aluminium tube for this. It needs to be either Stainless of wood in order to take the loads. I have been considering stainless tube bent into a U shape to attach either side of the bow, with a stay downwards to a strongpoint on the bow. You could actually utilise this to move the anchor rollers further forward, and thus clear the sides of the bow better.

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[extravert]

Re: "Bowsprit"

The Dragonflies have a bowsprit that fixes to a universal attachment at the top of the stem, rather than disappearing into a tube into the hull. You can see it here...

The problem with trying to fit this type of arrangement is bracing the forward end of the bowsprit against the considerable loads that will be encountered. When flying a sail you will have a force with components pulling upwards, sideways and backwards. Compression strength of the pole will support the latter, but unless you have some stays, you will not be able to counteract the first two.

The Dragonfly arrangement has a bobstay coming up from the stem above the waterline, and sidestays coming from the bow of each of the floats. You could add a bobstay, but I am not sure you will have sufficient angle on a monohull in order to be able to get enough sideways support from a sidestay. Diagram required...

This method of supporting a bowsprit by stays rather than an internal tube in the hull does not seem to be used for modern monohulls, which all have internal tubes (or old fashioned deck mounted ones). Maybe the side support issue is the reason why.

<hr width=100% size=1>One day, I want to be a real sailor. In the mean time I'll just keep tri-ing.

 

[snowleopard]

Re: \"Bowsprit\"

on racing machines this arrangement is common. the pole doesn't have to run along the centre line, it usually comes from one side at an angle so the end is on the centre line when extended. the pole is invariably carbon fibre and generally uses its stiffness to stand without a bobstay. the U-shaped fitting it slides in has to be massive and very strongly secured to the hull which is bound to require surgery.

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[alan]

Re: \"Bowsprit\"

Hi Extravert,

Thanks for the info. Yeah I think any single pole will need to be brought well back inboard in order to have some deck fittings which will absorb lateral forces on a monohull. The Swedish device I mentioned in my earler mail is interesting in this respect as it uses an "A" frame type of construction with a bobstay to counter the lifting force.

Alan.

<hr width=100% size=1>Alan Cloke