I want to add a small bowsprit to the front of my and have been wondering about using the forestay (jib) chainplate bracket as an attachment point. Nothing large - just big enough to fly a smaller jib or trysail. Certainly not for running a complete second genoa as Highlander's done, as this would involve a complete re-vamping of the mainmast stays in order to support the load. My hope is to enhance the drive of my genny (150) with a leading sail, similar to the leading slot on a STOL aircraft.
This raises two questions so far: Is the stock bracket strong enough for supporting the rear of a three foot bowsprit? Why are there two attachment holes in this fixture when you can only attach one stay to it?
Ross
When we purchased our last September, we got the BWY assymetrical spinnaker, and the package included the bowsprit (maybe 2.5'? I don't have it handy). It has a small block at the end on top for the tack line, and a loop at the end underneath to (presumably) tie it down to the bow eye.
It lays in the anchor roller via 2 pins, and is very easy to put on/take off. It doesn't have any attachment to the chain plate bracket. The mounting seems fairly sturdy (it's designed to tie down an assym, after all) so I would think that a small foresail should be fine.
You definitely want to run to the bow eye, where there's already an attachment point rated for it. This is how most real sprits are done, so that the sprit need only provide tension outward (in compression) and laterally. You won't find a tube strong enough to handle the necessary forestay tension on a 3' lever arm.
Given that, I like the anchor roller and a few pins idea. Simple and effective.
Thanks for that Clay! I would guess that the anchor roller becomes inactive when that occurs? If you get a chance anytime try and put up a boat picture with it in place. I'll have to check out BWY to see if it's still offered.
I've seen Highlanders setup first hand, and it's a thing of beauty - as well as being extremely strong but my needs, as you say, are probably similar to the lightweight assym you're running and maybe even less.
Went through Casper many many years back! I thought all the sailing was from horseback. Wyoming is beautiful!
mastreb wrote:You definitely want to run to the bow eye, where there's already an attachment point rated for it. This is how most real sprits are done, so that the sprit need only provide tension outward (in compression) and laterally. You won't find a tube strong enough to handle the necessary forestay tension on a 3' lever arm.
Given that, I like the anchor roller and a few pins idea. Simple and effective.
This is what I'm thinking: 2 - 3ft Aluminum tube. Diameter or thickness unknown (?). 1/4 inch hole drilled in the front chainplate at midpoint, which takes a SS securing bolt protruding from one end of the tube. The 'nose' end links to three adjustable stay shackles, one running to the bow eye (the winch strap attachment point) and one on each side connected with the bottom of the rear front pulpit stanchion for lateral resistance to counter side forces. Then a very small roller furler operating on the extra front stay. I'll try and work up a drawing.
Easy peasy, lemon breezy .... and cheap too!
Ross
Last edited by Crikey on Mon Jul 01, 2013 7:10 pm, edited 1 time in total.
Forgive the lousy artwork. The front chainplate seems robust enough to take a 1/4" hole without weakening critically, especially if you consider its load is mainly just pulling on it.
I'm not yet exactly clear how robust the sprit pipe should be (thickness and diameter) as it would be supported in four directions at the end and the load would be mainly compressive. I also guess the furler cable could be similar in diameter to one of the existing stays.
Is there a marine engineer in the forum?
R.
That screw will be subject to bending if its in a nut in the butt-end of the aluminum tube. You'll want a looser connection that can accommodate lateral and vertical movement.
Maybe an eyebolt through the chain plate fixed with nylocks, and then the sprit tube drilled for a quick pin? You just put the sprit over the eyebolt, put the pin through the sprit and eyebolt, and you're on. Connect the forestay and bow-eye and you're under tension.
I'd put a turnbuckle on the stay to the bow eye as well to adjust forestay tension.
Also be advised it is possible to bend the forestay chain plate on any loads that aren't inline with the forestay.
You could try this with a stock spreader tube. Pre-drilled $22.
Matt
mastreb wrote:That screw will be subject to bending if its in a nut in the butt-end of the aluminum tube. You'll want a looser connection that can accommodate lateral and vertical movement.
Maybe an eyebolt through the chain plate fixed with nylocks, and then the sprit tube drilled for a quick pin? You just put the sprit over the eyebolt, put the pin through the sprit and eyebolt, and you're on. Connect the forestay and bow-eye and you're under tension.
I'd put a turnbuckle on the stay to the bow eye as well to adjust forestay tension.
Also be advised it is possible to bend the forestay chain plate on any loads that aren't inline with the forestay.
You could try this with a stock spreader tube. Pre-drilled $22.
Matt
Excellent!
I will go with the quick pin idea as it will need dis-assembly before retrieval on some ramps and threads wouldn't last long with any rubbing.
Had the bow eye turnbuckle in mind for just that purpose.
It would be prudent to begin checking for bending from first use. An 'L' bracket doubled behind would be a solution for that.
I have access to a wrecked sailboat - so will try and see if I can save the twentytwo. Is this aluminum in the stock any different from the quality that I can buy at the 'Depot'?
R.
The pole slides into two 1 1/2 rings welded to the 1/4 plate front plate, which is also designed to be strong enough to carry the anchor system as well as being able to ram annoying powerboaters..
Even with the adjustable back stay it is not easy to get enough tension to get good race trim
Great for the cruising chute!
must have some more photos somewhere...
In theory, there is no difference between theory and practice;
In practice, there is. Restless art & engineering
Restless - now that's (99%) what I'm talking about! I think I could sidestep the plate if the lets me retain the existing anchor position but I'll have to go and have a better look - otherwise not too much extra work it would seem. I would love to see any extra pics if they surface, particularly the mounting hardware for the sides, and on the pole itself.
Also, got any further observations re the tensioning?
Ross
Baerkanu wrote:When we purchased our last September, we got the BWY assymetrical spinnaker, and the package included the bowsprit (maybe 2.5'? I don't have it handy). It has a small block at the end on top for the tack line, and a loop at the end underneath to (presumably) tie it down to the bow eye.
It lays in the anchor roller via 2 pins, and is very easy to put on/take off. It doesn't have any attachment to the chain plate bracket. The mounting seems fairly sturdy (it's designed to tie down an assym, after all) so I would think that a small foresail should be fine.
- Clay
Yes its a good ideal & they stole the design from my 3ft bowsprit that I designed for "Beene" Geoff & Terry out in Vancouver BC
Crikey wrote:Forgive the lousy artwork. The front chainplate seems robust enough to take a 1/4" hole without weakening critically, especially if you consider its load is mainly just pulling on it.
I'm not yet exactly clear how robust the sprit pipe should be (thickness and diameter) as it would be supported in four directions at the end and the load would be mainly compressive. I also guess the furler cable could be similar in diameter to one of the existing stays.
Is there a marine engineer in the forum?
R.
Thanks for that John. With yesterdays addition to my 'hat' closet yesterday, I'm probably going to run out of BBucks in time to have it done by the Rendevouz. Would you be able to bring the spare down with you for a perusal? Maybe you'll get 'lucky'.
Another question: Aren't you concerned by the lack of side support? I tend to think there would be some pretty substantial side forces involved if a jib was mounted. That anchor bracket is pretty flexible.
Crikey wrote:Thanks for that Clay! I would guess that the anchor roller becomes inactive when that occurs? If you get a chance anytime try and put up a boat picture with it in place. I'll have to check out BWY to see if it's still offered.
I've seen Highlanders setup first hand, and it's a thing of beauty - as well as being extremely strong but my needs, as you say, are probably similar to the lightweight assym you're running and maybe even less.
Went through Casper many many years back! I thought all the sailing was from horseback. Wyoming is beautiful!
Ross
Hi Ross -
I'll try to get some pics over the next few days - Highlander's setup is definitely stronger, the BWY version is just the "pole" portion and it literally lays in the anchor roller bracket, resting on the roller itself. All it is is a pole, 2 pins to attach it to the roller, and attachment points top/bottom at the end for the tack line and bow eye line. You can't use the anchor roller with it attached, but when on the hook overnight I just run the rode from one of the bow cleats overboard since the anchor roller would I think chafe the line, and (2) it's easy enough to raise the hook without using the roller, I find, as long as you can either stand at the bow or uncleat and raise at the stern.
Yes, WY's beautiful! And that's a good thing because the sailing sucks. But my job's portable, I've got a plane and Admiral works 7 on/7 off so it's pretty easy to take the boat somewhere good and commute back and forth if we want.
and have been wondering about using the forestay (jib) chainplate bracket as an attachment point. Nothing large - just big enough to fly a smaller jib or trysail. Certainly not for running a complete second genoa as Highlander's done, as this would involve a complete re-vamping of the mainmast stays in order to support the load. My hope is to enhance the drive of my genny (150) with a leading sail, similar to the leading slot on a STOL aircraft.
Wyoming is beautiful!
