Bowsprits - A couple questions?

[DangerousPirate]

There's a fantastic little bowsprit on this boat, one of those selden ones with a ring. I have a brand new code 0 and an asymmetric spinnaker and I think those sails will come in handy when the winds are low.



Now I was getting curious about pushing the bowsprit out further and support it with a bobstay to maybe allow a set up with 2 headsails. How practical is that? There are a few racing boats that do this.



Of course that's a different boat than mine (that's a mini transat 650, weighting three feathers and the skipper, and a fractional rig) and my boat is 9.5 metres, masthead rig and somewhere around 5 tons, but the principle should be the same, I assume.

The code 0 is for close reaching, and the asymm for broad reaching. Wouldn't the boat reach even greater speeds if I were to add the genoa as well? I understand there needs to be some spacing between the sails. And a bobstay is relatively uncomplicated to install. With that, the bowsprit could push out further. There is a need to install another d ring on the anchor locker door (ignore the dirt in the picture, I took it in the middle of powerwashing) and I think that is okay as the bobstay handles the real load (which is up) and the other end just pushes downwards. The only sturdy thing needs to be the door (which btw is quite sturdy but can always reinforce with a backing plate). The ring itself is only to keep it from pushing in, out, left and right. But doesn't carry any significant forces, to my understanding. Correct me if I am wrong though.


Does it make any sense to push the bowsprit out further and add a bobstay? Is it even practical to use code 0 / asymm spinnaker + Genoa? Or maybe another jib sail at some point in the future even?

I had not discovered the bowsprit yet when I sailed in low winds, but I was quite annoyed how I had to turn on the engine or bob around the see with 1-2 knots... A code 0 on the bowsprit would already help, but if I had the genoa up, too, I'd have a lot of canvas that should turn those 1-2 knots into maybe 4 or so?

All just a thought game so far. But what do you think? Is a bobstay necessary? Is the idea feasible? Or all just rubbish and I won't be able to use genoa + 2nd headsail anyway and I need to stop acting like I have a cutter?

 

[Chiara’s slave]

Side support might be difficult. We have 4ft, like the proverbial elephant, with a dyneema bobstay and side stays. Our side stays go to the amas, very conveniently. Code 0 luff is best part of 2m away from the forestay, but they just don’t work together. Same with the asymmetric.

 

[[194497]]

I think a genoa will generate a lot of upwards and sideways pull on the bowsprit, even in light winds, and if the bowsprit moves, the genoa luff will fall away into a curve and the boat won't make much if any progress to windward. So you'd definitely need a bobstay but also stays out to the sides, which might run at too fine an angle to do much good unless you put spreaders on the bowsprit, as seen on some big sailing ships...
A big, overlapping light-airs genoa cut in light fabric might do more good with a masthead rig.

 

[DangerousPirate]

So extending the bowsprit won't help fly more sails at once? I can use it as is, without needing to extend the bowsprit. I just thought if I push it forward a little, I create enough space to be able to fly 2 headsails at the same time and in certain tacks, give me an extra push. That was the hope anyway.

 

[Chiara’s slave]

So extending the bowsprit won't help fly more sails at once? I can use it as is, without needing to extend the bowsprit. I just thought if I push it forward a little, I create enough space to be able to fly 2 headsails at the same time and in certain tacks, give me an extra push. That was the hope anyway.

We get zero advantage from doing that. We are not a cutter. The advantage is gained in that you increase the size of the foretriangle for free flying headsails. We set a 440sq ft Code 0 using the bowsprit. Before spendung money though, you should think about helm balance.

 

[zoidberg]

I'm not going to suggest DangerousPirate is wrong. Rather, I'll illustrate what I've done, and why, for appropriate consideration.

My boat is lighter at around 3 tons and 70s 'old school' in shape. I acquired a furling asy sail so that dictated I investigate fitting a bowsprit. The Selden offerings ( and others ) are really neat - and so are the prices. I decided on a bit of DIY. The alloy tube I purchased is T6061, with an 89mm OD and a wall thickness of 6.2mm. That's rather a lot more than Selden's scantlings. ( see their diagram in #1 above )

The attentive will notice I used Selden's Bow Ring, for I couldn't make that bit up.

Over the years, I've seen 2, perhaps 3, DIY bowsprit arrangements fold. They used s/s tubing, which wasn't even close to robust enough. Perhaps it's now my turn....
Is there a need to secure the bobstay to the very end? There's substantial 'lever arm' in play. I'm hoping my borrowing a traditional 'bowsprit traveller' concept ( Classic Marine et al ) will suffice to share the UP-load with the Selden Bow Ring. I have, however, reinforced under the deck massively in way of the Seldon unit.

The leatherwork is just a bit of conceit. The whole arrangement cost me less than 1/10 the Selden price. It may suffice.

 

[DangerousPirate]

I'm not going to suggest DangerousPirate is wrong. Rather, I'll illustrate what I've done, and why, for appropriate consideration.

My boat is lighter at around 3 tons and 70s 'old school' in shape. I acquired a furling asy sail so that dictated I investigate fitting a bowsprit. The Selden offerings ( and others ) are really neat - and so are the prices. I decided on a bit of DIY. The alloy tube I purchased is T6061, with an 89mm OD and a wall thickness of 6.2mm. That's rather a lot more than Selden's scantlings. ( see their diagram in #1 above )

The attentive will notice I used Selden's Bow Ring, for I couldn't make that bit up.

Over the years, I've seen 2, perhaps 3, DIY bowsprit arrangements fold. They used s/s tubing, which wasn't even close to robust enough. Perhaps it's now my turn....
Is there a need to secure the bobstay to the very end? There's substantial 'lever arm' in play. I'm hoping my borrowing a traditional 'bowsprit traveller' concept ( Classic Marine et al ) will suffice to share the UP-load with the Selden Bow Ring. I have, however, reinforced under the deck massively in way of the Seldon unit.

The leatherwork is just a bit of conceit. The whole arrangement cost me less than 1/10 the Selden price. It may suffice.

Luckily for me, the bowsprit came with the boat - otherwise I’d probably never have fitted one either.
For yours, I’ve always thought that securing the bobstay right at the tip is the best way to directly counter the load without introducing leverage that could bend the tubing. But I see you've gone with a more traditional setup using a traveller to share the load with the bow ring. Interesting solution! Curious to see how it holds up with that chunky 6061. it certainly looks like it means business.

 

[Chiara’s slave]

Ours is a 50mm carbon tube, off the shelf, with custom stainless end fittings. The stays are rigged to the outboard end fitting, as is the tack outhaul. The bobstay runs to a fitting on the bow about 100mm above the static waterline, factory fitted. That fitting could have been lower, as soon as theres pressure in the sails the main hull starts to lift, but we’ve had no problems with the loading. The bobstay is 8mm dyneema with a Brummelman lock splice at each end. It makes an angle of about 30 degrees to the bowsprit. Cost would have probably been about £200, except a mate of mine has an engineering shop and can weld stainless.

 

[Blueboatman]

I favour a hinged, curved loop of stainless with mounts on the top sides of the boat not the deck .
Or carbon if you prefer like this photo

Thus you get more lateral support and a ‘step off’ platform at the front and can hinge/remove the assembly when the marina accountants tape measures appear.
A simple tackle to act as a bobstay/downhaul .
A lot of the Asian built yachts of the 70sand 80s sort of adopted this arrangement but made it a permanent stylistic ‘feature’ with flying handrails, teak foot boards, extra bow rollers etc .. which just adds weight and windage and complication and chargeable length imo

Article linky
A Guide to Bowsprit Configuration from upffront.com

 

[flaming]

So extending the bowsprit won't help fly more sails at once? I can use it as is, without needing to extend the bowsprit. I just thought if I push it forward a little, I create enough space to be able to fly 2 headsails at the same time and in certain tacks, give me an extra push. That was the hope anyway.

Even the racy boats with long prods don't fly jib and code at the same time. Instead they fly a staysail, tacked approx 2/3 of the way from the mast to the forestay. That should give you an idea of the seperation required. e.g.

 

[ashtead]

We have a box section bowsprit which mounts in the bow roller but it just there to push the attachment point for the Karver top down type furler forward for the cruising chute .you don’t fly the Genoa or jib if you fly the cruising chute though mainly as no real need .

 

[DangerousPirate]

Even the racy boats with long prods don't fly jib and code at the same time. Instead they fly a staysail, tacked approx 2/3 of the way from the mast to the forestay. That should give you an idea of the seperation required. e.g.

I am starting to think my idea was foolish. I don't think I could create that much space between sails, besides, I don't have a stay sail.

GUess I leave the set up as is then.

 

[[194497]]

Just looking back at your photos, how about getting a big overlapping genoa (150%) with a dyneema luff rope, and setting it free-flying from the bowsprit, with the bowsprit in the position shown in the pics? That would work wonders to windward or on a close reach in light airs and wouldn't require and change to the existing set-up. Obviously you'd have to buy an expensive new sail though...

 

[DangerousPirate]

Just looking back at your photos, how about getting a big overlapping genoa (150%) with a dyneema luff rope, and setting it free-flying from the bowsprit, with the bowsprit in the position shown in the pics? That would work wonders to windward or on a close reach in light airs and wouldn't require and change to the existing set-up. Obviously you'd have to buy an expensive new sail though...

That is an idea to play with.
So the questions, one needs to ask now are: downwind I'd use the Asymmetrical Spinnaker, upwind I'd use a 150% Genoa, And inbetween I'd use the Super 0. And when it gets stronger winds again (10-15+ knots) I'd just use the 135% Genoa?

How big would the gain be between the 135% and the 150%? Of course, the 150% is bigger, but only by 15%. There aren't worlds between them. I feel the super 0 and Asymmetric Spinnaker will have the upper hand in close reach all the way down to a run. And for tight upwind conditions, the difference between the 135% and the 150% might be marginal.

Not making a statement here, the questions aren't rhetorical. I really don't know, as I am not a racer or ever had so many different sales and a bowsprit, to play with.