DIY Bow Sprit for H260 or most small boats

Status
Not open for further replies.
Aug 9, 2005
825
Hunter 260 Sarasota,FL
Our 2004 h260 suffered from a lack of power on long runs off the wind with our rather small jib and B&R main. Attaching an asymmetrical sail directly to the bow plate would foul on my anchor and bow roller so I ventured into designing a 3' removable bow sprit. There are a few on the market but they would require it to be mounted over the anchor locker when deployed. I wanted unfettered access to my ground tackle, easy removal, single handed sail deployment/retrieval and enough strength to fly a 300sq' gennaker/asymmetrical on a broad reach in 10-12kts without a foredeck crewman.

(BOW SOCKET EPIPHANY)
After a dozen refinements and a few outright failures due to underestimating the load on windy/choppy days I've come to the perfect match so far on this boat. I used a carbon mast top from a windsurfing mast that I reinforced by inserting an oak dowel I'd buttered with thickened resin. It's stiff and handles the extreme load fine so far. The base is set into a bow socket I fabricated from 3 pieces of 3/16" SS plate and a SS tow ring from a ski boat. I cut out the rope tab inside the ring and the pole fits into it about 1/2" deep which allows slight side to side movement under load but will release if a stay breaks. The socket is tightly fitted over the decks nose section at the bow and shaped a bit like an upside down U. I ground a bit of a flat spot on the nose of the boat where the sprit would rest and through bolted the SS socket assy over the bow pulpit plate and down through the hull/deck joint.

(SPRIT & STAYS WITH GUSTO)
On the outward end of the sprit I used a 3/8" SS Eye, drilled in at an angle to accommodate the angle of the load for a straight pull to the mast spinnaker block. This main sprit eye will need to be welded closed due to the extreme loads. From this eye I also mounted two stays with turnbuckles that mount back on the port/starboard rails to SS eyes drilled through the deck/hull at an angle to allow for the angle of pull as much as possible. Down from the end of the sprit attach a 3-to-1 downhaul with low stretch spectra line. I had a single block w/ becket like a Harkin #167 down on the boats bow eye and a Harkin 2-to-1 with jam similar to a #244 tied on a short loop under the main sprit eye. Use only good quality SS cable and swage fittings set with about a 10degree rise and tension the downhaul rather aggressively because halyard tension is very taught on the furler.

(RIGGING NOT JUST RIGGED)
The stock mast block is plastic crap so don't even try it. Drill it out and replace it with a serious SS flush mount block for an internal halyard or mount an external bail and block. I think mine was a Garhauer piece. DO NOT mount a spinnaker/gennaker at the mast head on a 260, only use a mount roughly at the height of the side stay attachments and above the forestay. The furler I used is a Facnor FX900 continuous line furler. My sail was made to fit our 260 by Knighton sails out of Sarasota based on my rig and sprit dimensions at about 308sq'. You can't partially reef with this setup and it wouldn't matter anyway. If it's blowing more than a solid12kts this sail is far too big for this boat. The furling line runs in a loop back to the cockpit so I can easily deploy or retrieve it when single handing. Sheets are 5/16", running back to blocks with webbing strap set low at the stern rails and then routed up to my new ST winches. You'll need your winches if it's blowing over about 8kts.

There's probably more but I'm way long already so good luck if you go for it. There'll be more pics to come I'm sure. The 1st pic was an early mock up for measurements that failed but I'd wildly underestimated the load anyway so build it stronger than you think it'd need. If we're out for the weekend I'll leave this sail furled in place. It's the easiest to deploy and supplements the whole sail set well on an average day. Now I'm sorta running out of projects...but we'll see about that.

Aloha,
Mike and kelli
 

Attachments

Last edited:
May 16, 2007
1,509
Boatless ! 26 Ottawa, Ontario
Hey Mike, very interesting project. You did a great job, looks very strong. I don't know if I'm ready for this yet but will keep it on my list for the future. Still have a few other projects to clear first.

thanks, Bob
 
Jun 16, 2010
495
In search of my next boat Palm Harbor, FL
Why not just use a geneoa and a wisker pole? And i see from your picture that you are sailing with a reefed sail, wouldnt it be time to pull in your spinnaker?
 
Aug 9, 2005
825
Hunter 260 Sarasota,FL
Bob, It wasn't an easy project but I posted so that those who are interested can save time/effort by learning from my earlier design deficiencies. It needed to be very strong but lightweight. Very rigid but easily deployed and removed. I expect my turnbuckles to be the weakest link at this point but they're holding up well so far. Good luck with your other projects.

Ina, The pic was of an early hoist to see how much strain it'd take under load on a downwind run or two. Our large roach main covers any foresail downwind so I was trying numerous sail sets and angles out in Boca Grande pass(notoriously nasty test site). It seemed prudent to know where and what rigging would break first while having a beautiful beach to heal my wounded rig;). I broke a bunch of rigging before I came down to something that I could easily remove from the boat, fly singlehanded and safely furl from the cockpit in under 30sec. It takes just about that long to remove the entire sprit too. It's a problem free, easily stowed design at this point.

On to my next revision....or not. Mike
 

Attachments

Alan

.
Jun 2, 2004
4,174
Hunter 35.5 LI, NY
Soling, looks like a pretty nice setup. Did you design it to be able to articulate also? The one I designed for my boat would be able to articulate if I had a track on the inboard end. Mine has a projection of 66" and carries a 1300 sq ft asym. The sprit pole itself doesn't have a tip support as yours does but it does have a calculated 2500 lbs capacity. The tack block is rated at 1500 lbs breaking load making it the fail safe point. My sprit deploys and retracts manually in a few seconds. I launch and retrieve the sail through the fore peak hatch when cruising. In race conditions we usually drop it behind the main and douse into the companionway.
 

Attachments

Aug 9, 2005
825
Hunter 260 Sarasota,FL
Alan,
That's a whole different ball game and I'm impressed. Finding the right part to fail before overload causes chaos is the primary trick. I love the simplicity of the Forespar style bowsprit mount but my small boat lacks any deck space up front so I ended up with the bow socket setup and stays but no articulation at this point(although it has unintentionally done so on prototypes). How does the tail of the sprit mount on deck when it's under load and how do you stow it when not in use?

Love the shot of your boat running under sail. Nicely done project.
Mike
 

Alan

.
Jun 2, 2004
4,174
Hunter 35.5 LI, NY
I didn't like Forespar's mount because it did not articulate and it mounted to the bow rail which limits its load capacity. I designed and built the mount to rotate the sprit out of the way of the anchor locker hatch when not deployed. The inboard end of the sprit attaches to the deck or toerail with a spinnaker pole chock located at each location. To deploy, I open the trigger clip on the pole fitting from the rail mounted chock slide it forward through the forward mount and clip it into the other chock mounted just aft of the anchor locker. I use the spinnaker pole foreguy to control the tack line adjustment.
 

Attachments

May 16, 2007
1,509
Boatless ! 26 Ottawa, Ontario
Alan, smart, well done, nice clean setup and it stores well on the side. Great pictures, easy to see how you did it.
Thanks, Bob
 
Status
Not open for further replies.