A New Gaff Rig for Wee Barkie

[auscruisertom]

Re: A New Gaff Rig for Wee Barkie

I'm not sure I'm really absorbing all the details, but is the length of mast where you can fit the luff of the mainsail the same on the proposed new couta boat mast as on the original? If so, you're in the money. How tall the mast is relative to where her standing rig attaches oughtn't matter so long as you can get the same sailplan on it.

If not, and you're going to try and compensate for a shorter luff and that loss of sail area by using a longer gaff and/or boom, you're going to change the way she handles --maybe a lot. A longer gaff will move her mainsail's center of effort aft, and thus increase her weather helm. If it peaks higher, that'll move the CE up a bit, and that too will result in a heavier weather helm, especially in stronger winds. You could balance that change by lengthening her bowsprit and extending her foretriangle forward, which would pull the CE back forward and down --but you're also talking about increasing her sail area then, too, which I'm not sure how you feel about.

If it were me, I'd be breaking out some paper and a straightedge, drawing the original, known sailplan in ink, and then drawing the proposed new sailplan over it in pencil. If, with copious use of eraser and graphite, I couldn't get the new combined CE to line up with the old one, I'd be thinking about a different course of action --i.e. a different mast than the couta boat mast.

And all of that is assuming 1) you know how well her helm balanced originally, and 2) you want to recreate her original helm balance. If you knew, for instance, that she had a lee helm originally, then by all means lengthen her gaff and move her CE aft to correct that fault. If, on the other hand, you knew she had a heavy weather helm, I would be hesitant to let that CE slip aft unless you were also going to modify her underwater profile to change her CLP and balance her out thus. (Which isn't that difficult a modification: I added a carefully-positioned, inch-thick wormshoe to the bottom of Bucephalus's keel and, to my shock, radically improved her fierce weather helm.)

All that aside, and looking at the photo in post #10, I think the longer gaff you propose could look quite smart.

Alex

I appreciate your reply Alex .
The luff will be the same or possibly lengthened slightly.

I also like the longer higher peak gaff especially as I will not be adding a top sail. And since the opportunity presented itself with a mast with a longer gaff I immediately contemplated a small increase in sail area,as I race the boat occasionally, and reefing is easily accomplished.

I have put pen to paper in line with your suggestion regarding slippage aft of the CE . My gut instinct tells me the higher Gaff in Couta boat style will work fine.
Interesting to note your modification of Bucephalus’s keel. Interesting name can we see what she looks like?

[auscruisertom]

Re: A New Gaff Rig for Wee Barkie

Tom, have you seen this thread?

http://forum.woodenboat.com/showthread.php?244921-35-ft-Ferro-quot-Couta-Boat-quot-Mast-replacement

I just left some comments ,and a sketch,that may be of interest to you.

I only just glanced at it .Presently Nellie and I are renovating our 25 year old house just completely gutted and re sheathed and partially rebuild two bathrooms and a toilet in the last five days.
And I won’t be putting my feet up ,hauling WB tomorrow between getting the Tammie trailer ready to pick up my mast and finishing of the reno.

It’s great to be retired and active .

[BBSebens]

Re: A New Gaff Rig for Wee Barkie

I also like the longer higher peak gaff especially as I will not be adding a top sail. And since the opportunity presented itself with a mast with a longer gaff I immediately contemplated a small increase in sail area,as I race the boat occasionally, and reefing is easily accomplished.

Why? With a nice long gaff, adding a tops'l should be easy! Besides, gaffs look better with a top.

[Pitsligo]

Re: A New Gaff Rig for Wee Barkie

The luff will be the same or possibly lengthened slightly.

I also like the longer higher peak gaff especially as I will not be adding a top sail. And since the opportunity presented itself with a mast with a longer gaff I immediately contemplated a small increase in sail area,as I race the boat occasionally, and reefing is easily accomplished.

I have put pen to paper in line with your suggestion regarding slippage aft of the CE . My gut instinct tells me the higher Gaff in Couta boat style will work fine.
Interesting to note your modification of Bucephalus’s keel.

All of that sounds good: same luff; more sail area at the end of the gaff, but with a higher peaking gaff to keep the CE a bit forward. Give it a try. At worst, it's a good excuse for a bigger jib, right?

My sense is that the gaff rigs with higher peaking gaffs tend to have slightly better windward performance --maybe. Hard to say. There are a lot of variables, and it might simply be that the gaff rigged boats intended for a career where they need exceptional windward performance *also* have high peaking gaffs as *one of* their attributes. Causality can become a bit suspect.

With a nice long gaff, adding a tops'l should be easy! Besides, gaffs look better with a top.

That's a good point, about the aesthetics. That said, no one can accuse a yard topsail of making a boat simpler to manage. After thirty years flying a yard topsail I'm not about to stop, but neither would I blame anyone for avoiding that complication.

Interesting name can we see what she looks like?

Bucephalus is rather the social butterfly on the Forum, and puts in appearances on every third thread, it seems. *Mostly* I'm not the one posting --blame Peter Sibley for that -- but I'm a bit chagrined at how big a presence she has, and I don't want to hijack your thread. She's showcased throughout this thread here, if you like: http://forum.woodenboat.com/showthread.php?244400-Pr0n

Alex

[skaraborgcraft]

Re: A New Gaff Rig for Wee Barkie

Why was she converted to her current rig, and did the previous owner consider it to be better? It looks like a well sorted rig, why do you wish to revert back to gaff?

[auscruisertom]

Re: A New Gaff Rig for Wee Barkie

Why? With a nice long gaff, adding a tops'l should be easy! Besides, gaffs look better with a top.

Good point on the long gaff ,I can probably rustle up a light 16’skiff jib that I can recut.

[Pitsligo]

Re: A New Gaff Rig for Wee Barkie

What I've found about B's yard topsail is that it doesn't change the CE at all, fore and aft. It shifts it vertically, of course, so there's a wee bit more weather helm apparent as her angle of heel increases, but the increase isn't as much as you might expect. And as a "first reef," dousing the topsail is very effective at making the boat more controllable.

Alex

[auscruisertom]

Re: A New Gaff Rig for Wee Barkie

All of that sounds good: same luff; more sail area at the end of the gaff, but with a higher peaking gaff to keep the CE a bit forward. Give it a try. At worst, it's a good excuse for a bigger jib, right?Quote=

I have already increased the jib size marginally and I would’ve concerned of loosing the good slot WB has between her staysail and the jib.
I have found while racing her cutter rig to be superior and surprisingly even running 150% Genoa with more sail area does not match the jib staysail combo.

My sense is that the gaff rigs with higher peaking gaffs tend to have slightly better windward performance --maybe. Hard to say. There are a lot of variables, and it might simply be that the gaff rigged boats intended for a career where they need exceptional windward performance *also* have high peaking gaffs as *one of* their attributes. Causality can become a bit suspect. Quote=

In my case the higher gaff would assist in river sailing where wind flow is interrupted by trees lining the shore.


That's a good point, about the aesthetics. That said, no one can accuse a yard topsail of making a boat simpler to manage. After thirty years flying a yard topsail I'm not about to stop, but neither would I blame anyone for avoiding that complication. Quote=

Frequently I sail WB with just the main and staysail due to her generous sail area. I could however visualise utilising the top sail as a light air and dress up sail for special occasions .


Bucephalus is rather the social butterfly on the Forum, and puts in appearances on every third thread, it seems. *Mostly* I'm not the one posting --blame Peter Sibley for that -- but I'm a bit chagrined at how big a presence she has, and I don't want to hijack your thread. She's showcased throughout this thread here, if you like: http://forum.woodenboat.com/showthread.php?244400-Pr0n

Alex

Hijack away I have never objected to being hijacked by a a pretty lass while singlehanding in the past.

[John B]

Re: A New Gaff Rig for Wee Barkie

As Alex says , most 'old' designers did not count the topsail in their C/E calcs. In the 50 or 100 sailplans I drew while nailing down details for my conversion from bermudan back to gaff, comparing the effect of different gaff lengths and boom length and bowsprit lengths etc , I found exactly that .
But as far as gaff evolution is concerned I have no doubt at all that a high peak gaff was a development over a topsail rig from a performance point of view. But that performance is about race track not day to day , and the important thing about racing a yacht around a course is not just about ultimate degrees off the wind, its more about how fast the boat / rig can accomodate changes in wind strength. Or it is here anyway. I've literally raced in harbour with 5 to 45 knots, but its usually more like say a light wind start and getting hammered in 20 or 25 to finish.
So the boat that can go around with least disruption to sailplan is fastest. That includes getting a topsail off still moving or reefing a big gaff main on the go, something that wasn't practical on my Edwardian type, overcanvassed style rig with its 28 ft light boom. I would reef before the race if there was 20 plus in the forecast and shake it out easily ( if the breeze didn't eventuate)rather than lose time reefing down in the race.
Your style rig with its heavy boom will reef down fine and relatively fast so you can exclude that hindrance.

That old sailplan with its CLR marked looks useful... is as good as any to make any rig C/E comparisons off. Call that mark the datum to compare the leads of various plans off.

[Pitsligo]

Re: A New Gaff Rig for Wee Barkie

Speaking strictly in the theoretical, like John B I was surprised, when I was designing "The Big Rig" that I'd one day like to fit to Bucephalus, how little the topsail changed anything as I shifted the gaff length and angle, boom length, bowsprit, foretriangle composition, etc. Topsails don't seem problematic for fore and aft CE calculations, just vertical.

Just speaking for myself, if the name of the game is genuine racing, with the pragmatism that demands, I would rather as few individual sails as possible to manage, for just the reason John B states: keep your sailplan management during the race as simple as possible. I love B's topsail for any number of reasons, but simplicity isn't one of them. If I were looking at keeping the sailplan tuned to the wind conditions over a long racecourse, where I might have to shorten or increase sail, I would far rather repeatedly tuck in or shake out reefs on the main than repeatedly be sending the "kite" aloft or lowering it to the deck. In other words:

the boat that can go around with least disruption to sailplan is fastest.

B and I never race, so that isn't an issue for us. If the wind gets heavy, down comes the kite. If it lightens up again, well, whether the kite goes back up depends entirely on how energetic/impatient I'm feeling, but there isn't any rush. I enjoy the aesthetics of the kite, and the novelty/celebrity/idiosyncracy of flying one on a 19' sloop. I appreciate how well she sails bald, with the kite stowed as a first reef and the main keeping its designed shape unaffected by a tied-in reef. I enjoy how much power the kite, way up high, adds in light air --far out of proportion to its diminutive size. But a topsail isn't without costs and frustrations, and me raving about B's shouldn't neccessarily be a sign that WB needs one.

I'll also say "amen!" to John B's comment about the utility of the old sailplan marked with the CLR. That's invaluable. I will say that I'm surprised how much CE/CLR lead WB has on paper. I expect that's because I'm unfamiliar with the hull type.

Alex

P.S. Here's your hijacking, then :

[auscruisertom]

Re: A New Gaff Rig for Wee Barkie

Why was she converted to her current rig, and did the previous owner consider it to be better? It looks like a well sorted rig, why do you wish to revert back to gaff?

WB second owner Stephen Clode an Engineer made the rig conversion , I am not entirely sure what his motivation was .although I do recall him mentioning the heavy weight of the original gaff mast.
His brother John Clode a shipwright sailed her under Gaff rig across Bass Straight from Adelaide to Sydney . John spent considerable time sailing WB enjoying Sydney and also becoming friends with the Kerr’s aboard Curlew ,while racing with the local Gaffer crowd .John cared for WB during Stephens stints working in NG but lost interest in her after her conversion.

WB rig is unusual a 31” mast double sleeved from below the hounds upwards with no spreaders and a set of runners. Both the staysail and jib have double halyards,and then there is that massive boom just shy of 16’ with a fully battened main saill.

Reverting back .There a a verity of influencers from her builder to people that had an association with her.
Possibly a degree of nostalgia and wanting to restore her back to original .,

[auscruisertom]

Re: A New Gaff Rig for Wee Barkie

After a full on week bum up renovating at home this was a nice change. WB being hauled late yesterday afternoon on the Tweed slipway with some therapeutic pressure washing finished in the fading light.

[IMG][/IMG]

[skaraborgcraft]

Re: A New Gaff Rig for Wee Barkie

Possibly a degree of nostalgia and wanting to restore her back to original .,

Good enough reason for some. I only asked as i had a bermudan cutter, although it was designed like that from the begining, but not a chance i would convert to gaff. Having said that, the last bare hull i fitted out was with gaff
as i could not afford the materials for a long mast and twin furling gears. Safe to say both will get you where you want to go. 16ft boom on a boat of that size is a bit of a handfull, but a shorter gaff boom has knocked me out. I would seriously look at making sure a boom will clear your head while standing in the cockpit, even if it has to lose a bit of area to do so.

[auscruisertom]

Re: A New Gaff Rig for Wee Barkie

Couple of pictures of the haul out.

[IMG][/IMG]

[auscruisertom]

Re: A New Gaff Rig for Wee Barkie

Quick and dirty copper shoe replacement ,which was damaged when hitting an abandoned mooring block.

[IMG][/IMG]