Sprit Rig to Gaff Rig conversion?

[shadow99]

I'm I asking for more trouble :confused: ? I've modified the rig 3 times since building her 4 yrs ago. She was a Shell Boat Designed "Swifty 12," now "Swifty 15 1/2," the mast was a 16' folding 2pc unit unstayed. Now it's one piece, with a forestay, and port & stbd baby stays. It's a very solid rig, yet the sprit stick boom rig drives me nuts.
Last year I added sail track, main sail halyard & had the mainsail modified so it could be reefed, but only when stationary (beached or docked). Any attempts to reef while underway have caused panic :eek: with the "female crewmember" as the boat tends to broach when someone moves forward onto the deck.
I saw in the Mystic-Noank,CT area, a guy in what seemed to be a Haven 12 1/2, gaff rig go from a full up main to a double reef, by himself, under sail, quickly & easily. That inspired me, &/or is gonna give me an ulcer.
Should I worry about the additional weight aloft with the gaff, peak blocks, & throat blocks. I don't expect any better windward performance, and they'll be more strings to pull. I've done a mock-up scale model, and it looks good, stealing a sailplan off another simular sq. footage boat, but will it function is another thing.
The "other-half," thinks "I'm outta my mind," modifiying the boat again :rolleyes: , grampa always told me "More is Better." Anyone willing too second this conversion, or should I just keep what I got?

Rick

[Ian McColgin]

Playing with alternative rigs is great if you've the energy, which you appear to have.

You're probably talking about a taller mast but you might go bird's mouth and come out nicely.

Were I considering this, I'd contemplate one of two options -

A biggish gaff with first reef at a moderate to fresh breeze - Force 4 to 5 - and room for a topsail at light breeze, Force 2.

Or maybe a little higher mast and no topsail, a curved short gaff with just one hallyard as the dutch have used and both Bolger and LFH have examples. Maybe for this plan first reef in the low end of Force 4 Moderate Breeze.

I'm not a huge fan of spritsail rigs but for the right boat, and yours may be one, the value of stowability for the whole rig in the boat and the fact that if you really have to go to weather you'll row anyway may outweigh the inferior performance.

Maybe enter into a professional relationship with someone like Todd Bradshaw or one of the many locals you have available like my old pal the former Captain of Goblin Kate . . . blanking on last name but I hear she has a canvass and/or sail business down in New London or so. Lots of local talent who like wee boats and could help you design a nice thing.

[shadow99]

Ian,
I did extend the mast by 2' to 18' in the design, the gaff works out to be 6' long peaked at about 45-50 degrees, the boom will be 10' LOA, all birdmouth construction on the spars.
But the placement of the boom off the deck, head clearance, is a good dilemma :confused: . I also thought of using a topsail, the cornish yard style, out of J. Leatherman's Gaff Rig book. Been reading Hand, Reef & Steer, for referances as well. I'm I headed in the right direction? Or I'm I spitting into the wind?

Rick

[Ian McColgin]

I googled over to look at the rig and realize now that you may have a sprit-boom rig as shown in the pix. I'd been thinking it was a sprit rig as in a four sided sail.

The Shells look a bit skimpy on the sail area department and I thoroughly approve of enlargement. The sprit-boom really is the best solution to not crashing the head and some visibility. Also when off the wind a boat like this can oscilate. A regular horizontal boom sufficiently low that you've nice sail area could all too easily dip and catch in the water, both causing you to broach leeward and holding the sail full of wind risking capsize if you don't accidently gybe first.

Lots of boats, Beetle Cats to Cotuit skiffs, have a nice low boom and you just sit in the bottom of the boat and enjoy. May work well for you. But, just some thoughts on the sprit-boom rig before leaving it.

I have a pretty big sprit-boom rig for my dory Leeward. The sail must be lowered to reef. I live in and use the boat in boisterous conditions but have had no problem. When I luff up and then move forward to where I can lower the sail, my weight puts the bow enough down that Leeward sits docily into the wind. It helps that I have a unique helm that locks in place easily. You will need to have a way of centering the helm and keeping it there, perhaps a line permanently secured to one gunnel that can be passed around the tiller a time or two and made fast to the other gunnel.

With the sail down, putting the reef in is easy. I keep the reef clew line on the sail so I can just secure it to the sprit-boom over a bit of whipping that both marks the spot and helps keep the clewline from slipping. The snotter is securely rove through blocks and won't get lost while the sail goes up.

Once the sail is back up I move aft a bit and steer backwards letting the sail pay out luffing until I'm far enough off the wind to get to steering speed before she tries to round up as the sail is trimmed. Leeward has a very small rudder and that can be a problem.

The rig can be forced in irons - the cat boat version of hove-to - with the helm secured about half way down and the sail trimmed for a tight reach. She'll woggle: Sail luffing - making sternway - helm (in reverse) forcing her off the wind - sail filling - gathers way - helm puts her more into the wind - sail luffing - making sternway . . . .

Very relaxing if you must kneel and discretely aim over the leeward side while female crew eyes are averted.

A boat like this has lots of room for trim and you could add a jib, perhaps compensating by putting your weight a hair further forward as needed.

If you want more sail area that can go up and down easily, a cool little self-tending jib might be in order. As you'll see presently, you might need to loose the headstay. Or set up a line that is a head stay when no jib is set but is a hallyard for the jib. The mast won't fall over while your luffing the main and setting the jib.

This unit sets flying with the foot laced to a club. The unusual feature is that the club is secured to pivot on the stem maybe 1/4 or so back from the tack. No need to be fancy - a siezed on ring and snap shackle that can clip to your stem fitting will do fine.

The rig gves you a sort of moveable mini-bowsprit. This rig is nicely self-tending/self-vanging and, because it thrusts the jib's luff a little to weather, seems to increase however the slot effect works.

G'luck

[shadow99]

I guess I fogot to mention, I'm flying a 130% Geneoa on a CDI FF1 furling unit off the bowsprit (part of the original 1st yr modification), and an 18sqft self-tending jib on a club. I've got enough headsail square footage to choke a horse! See pics from '04 in Noank,CT at website below.

Rick

http://pak02.pictures.aol.com/NASApp/ygp/GuestLoginevent=DirectView&shareInfo=mFQYMXJcDsUImUr8PNCZ0TB78U%2fydUO3uwZuzb 4I L4q%2fjFCnkV3ciA%3d%3d&pageName=AlbumViewFromEmails

[tidmarsh]

It looks like you could use a shorter mast with a gaff rig than the sprit-boomed sail shown on the website.

My 12' catboat has an 81 sq. ft. sail with a 14' mast, 11' boom, and 8' gaff. To keep the handling balanced, you'll probably need to move the mast step forward.

The small gaff rig I use is fairly simple: I have two blocks at the masthead for the peak and throat halyards, which run down, through deck blocks, and are cleated just forward of the coaming. I use a combination mainsheet/downhaul the adjust luff tension, which I got from a drawing by Todd Bradshaw on this forum.

If you look closely, you can see most of the rig (along with lazyjacks and jiffy reefing) in this photo:
http://216.77.188.54/coDataImages/p/Groups/147/147689/folders/153497/1102916billted1.JPG

You might also consider rigging a balanced lugsail, to gain reefability with a simpler rig (only 1 halyard).

[Ian McColgin]

I couldn't get the pix up but the more I learn the more I can say

You go Shadow!

[shadow99]

Thanks Ian! I can't figure out why the link will not work. I copied the link at the webpage, and pasted it to an Outlook e-mail message,(so I could have easy access to it). It works off the e-mail, but screws up everytime I insert it into post reply.
I tried the "Instructions for posting pictures," off the WBF, but those procedures only work with Imagestation, and Imagestation wouldn't accept my e-mail address, for some reason, so I could not join, & post my images there instead of AOL.

Rick

[Ian McColgin]

If you make the Mystic EBS, bring pix.

[Steve Miller]

I also have one of Shell's Swifty 12's. I added a jib for more sail area. If that's too much then I can sail main only. To tame the helm when sailing on a reach or especially down wind I built a longer (deeper) narrower rudder. It changes the way the boat sails completely. I was sort of amazed at the improvement. I am now on the 3rd version of the rudder. This one has a pivoting blade - you can see the up and down lines in the photo.

http://www.hevanet.com/kg7pv/newrudder.jpg

[shadow99]

OK Ian,
An "EBS" meeting in Mystic? Is that considered "A functional meeting of the minds, for the purpose of discussing logical solutions to what :D (ALES) :D our vessels," right? Sounds like wonderful excuse to me, now if I can get the other-half to buy that ;) , I'm in.

Tidmarsh,
Did ya get my e-mail yet? I've put my model down, grabbed my tape measure, and I am heading into the forest (lumberyard) to get some goodies. Presents from Lee Valley arrived today :D , birdsmouth 6/12 & 8 sided bits. Gonna run some mast samples today, so I can be sure I got the diameter right.

Steve,
I modified my rudder somewhat like yours, mine involved adding to the existing rudder, a piece of 1/4 " 2024-T6 Aluminum plate drops out of the lower blade, effectively doubling the size of the rudder. Does have some hangups thou, the chord of the blade makes for a "touchy" helm, and she doesn't always retract back into the blade. Tolerance between rudder cheeks & plate is 0.01-0.025" maybe a bit too tight.

Regards to All,

Rick

[tidmarsh]

Got it, Rick.

Here are the photos:
http://216.77.188.54/coDataImages/p/Groups/147/147689/folders/194592/1465070ek12.jpg

http://216.77.188.54/coDataImages/p/Groups/147/147689/folders/194592/1465071ek13.jpg