Adding a (retractable) bowsprit to a cutter?

[GTom]

Is it a good idea to boost sail area on a heavy-ish cutter by adding a bowsprit? I am considering a heavy classic boat as a first purchase but I don't necessarily want to motor in light winds.

How much can a bowsprit bring, e.g. 4ft on a 38-40ft cutter or sloop?

[UNCIVILIZED]

Much of how long it can be depends on the design & construction of the boat's hull & rig. As it requires quite a stout stem to rest on where it meets the boat, a rock solid bracket/connecting hardware at this location, & ditto at it's butt end. Including a very, very stout bulkhead or post underneath of it's butt end, as this part of the sprit presses downwards with quite a bit of force.

Some other considerations are;
- The size & mounting of the stem fitting for the bobstay down by the waterline.
- The sizes & angles of the bobstay, & sidestays.
- The sidestay tangs, & their attachment points & method.
- The cranse iron.
- The headstay at the sprit's tip & also where & how it's connected to the mast.
- Ditto on your inner forestay (formerly your headstay).
- Possible changes in backstay & shroud loadings. Same with regards to compressive forces on the mast tube itself.
- Lead angle of jib halyard to sail, especially if it's on a furler.
- Compressive & Lateral forces on the sprit itself.
- Construction of the sprit. Including materials, & design. To include bow platforms if any, as well as anchor rollers, etc.
- Anchoring loads seen by the sprit.

In terms of how large a sprit you can have. Such is dictated by much of the above. And if you so choose, they can be very, very long. For example on a Hans Christian 32' the sprit is about 8' long IIRC. And on some racing skiffs, the sprit is just about as long as the boat.

But bottom line, it's design should be integrated into, & integral to the boat's other rigging. As all of the pieces depend upon one another in order to function well.

A source of some info of how long the sprits are on many of the more traditional designs is the site www.bluewaterboats.org And Brion Toss's books cover a good deal of what goes into their design, along with their rigging. For example The Rigger's Apprentice books by him. I have the 1997 edition, & can't say as to how well various topics are covered in the newer one. But likely some other members here can. Or you could call his shop & ask.


EDIT: I may have aimed my answer incorrectly with regards to your question. For simple, retractable, deck mounted sprit kits, there are a number of them sold by Selden & many others. Some of which are found on the spar maker's websites, as well as at places like www.VelaSailingSupply.com

Which size you choose depends on what you want in terms of length, the application it'll be used for, loads it'll see, etc. But one up to about 2m in length is fairly easily within the realm of the possible. Perhaps a bit less if you're flying a sail with a 2:1 halyard or tack purchase.

It's also possible to do a DIY build, both in carbon fiber, & aluminum. Or wood, or a wood/carbon fiber hybrid for that matter.

[a64pilot]

Being faced with a similar problem, ( heavy cutter rigged boat not known for light wind performance)
I went with a cruising code zero. I know it will not make my boat a light weight racer, but ought to help considerably in light winds, and doesn't require major structural modifications

[roverhi]

Heavy cutter!!!! Doesn't that type of boat already have a bowsprit??

A lot of boats have had bowsprits added to them mostly to balance out the boat. Only after you know how the boat handles will you be able to determine whether you can add a bowsprit. How long it needs to be would be a trial and error determination though a Naval Architect could make an educated guess.

As A64Pilot says, a code zero or asymmetric spinnaker could accomplish what you want without the hassle and expense of adding a bowsprit.

[GTom]

The Malo-s, Hallberg-Rassy-s, rivals I am looking at come without bowsprit. Isn't a code0 yankee problematic on a cutter? I know, tacking is more cumbersome but what about efficiency vs a bowsprit-rigged (normal size) yankee?

Absolutely agreed regarding expert opinion before changing anything, just asking if someone has experience with a retrofitted bowsprit.

[roverhi]

An asym. is a lot easier sail to handle on a bowsprit with the asym. tack in front of the headstay. With the sail tack out in front of everything, you can jibe by letting the loaded sheet fly and haul on the other sheet bringing sail around forward of the mast. On my current set up with the asym. tacked behind the headstay, use the sock to douse the sail, release the tack and move the sail around the headstay reattach the tack and hoist the sock. In short, it's a pain without a bowsprit. Haven't tried it but assume

Deck mounted deployable bowsprits are available and seem to work fine for asym's and probably Code Zero's. Without the need to support the mast, only the luff of the sail, they aren't that heavily loaded. A question for those that have them or have used them, do they work without a bobstay or do you have to rig an adjustable bobstay??

I'm an old Westail guy and assumed you were talking a permanent bowsprit that a few sloops have added to turn into stutters and ameliorate weather helm.

[lateral]

Originally Posted by roverhi

An asym. is a lot easier sail to handle on a bowsprit with the asym. tack in front of the headstay. With the sail tack out in front of everything, you can jibe by letting the loaded sheet fly and haul on the other sheet bringing sail around forward of the mast. On my current set up with the asym. tacked behind the headstay, use the sock to douse the sail, release the tack and move the sail around the headstay reattach the tack and hoist the sock. In short, it's a pain without a bowsprit. Haven't tried it but assume

Deck mounted deployable bowsprits are available and seem to work fine for asym's and probably Code Zero's. Without the need to support the mast, only the luff of the sail, they aren't that heavily loaded. A question for those that have them or have used them, do they work without a bobstay or do you have to rig an adjustable bobstay??

I'm an old Westail guy and assumed you were talking a permanent bowsprit that a few sloops have added to turn into stutters and ameliorate weather helm.

Hmmm, me too.
I don't want to have a bobstay but fab up a sprite for an A0 or A1 with enough
clearance for a top down and around the front of headstay gybe.

[mikedefieslife]

I've seen catamarans with code 0 sails where the bowsprit (it's not really a bow sprit, but still) is only maybe 40cm away from the genoa furling, and the attachment at the mast less than 30cm higher.

I thought that most people don't tack code 0 but instead furl them then unfurl them again.

[lateral]

Originally Posted by mikedefieslife

I've seen catamarans with code 0 sails where the bowsprit (it's not really a bow sprit, but still) is only maybe 40cm away from the genoa furling, and the attachment at the mast less than 30cm higher.

I thought that most people don't tack code 0 but instead furl them then unfurl them again.

Fundamental eh..... Watson!
Coffee hadn't kicked in.

Watched a race boat dropping an A0 and gybing. But they were too lazy to hoist again as finish line and rum were close. Different story if it was furled.
lotta work hauling it in. We had to make do with a poled genny.

[Suijin]

Adding a bow sprit is not going to make a heavy cutter go much better in light winds. It will change the handling of the boat though. A Valiant 40 owner added a bow sprit to his boat (actually to give it a solent-style rig) and found the weather helm much improved. Bob Perry liked it so much it became a feature of the V42.

If you want your boat to perform better in light air... make it lighter or get light air sails or both.