PDA

View Full Version : Wolf in Sheeps Clothing - A Gaffer?



Foster Price
05-28-2001, 05:16 AM
Hello Guys

I'm still pondering the next boat. I've written a very detailed usage scenario but am having trouble getting the design concepts established. I have come across the French concept of "Esprit Retro" which roughly implies "something technically modern created in a past style.

JP Tutard and JP Brouns have both done some boats (including Gaffers) in this spirit.

Could my new 5.5 tonne 35' boat have a gaff rig and still frighten the hell out of the IMS guys (not necessarily round the bouys or even a coastal race but just ocasionally "boat on boat")???

What is the optimal form for such a rig?

Does anyone know of any designers doing this sort of stuff??

Regards - Foster

PugetSound
05-28-2001, 01:07 PM
The big disadvantages of gaffers over modern 'marconi' rigs are the topside weight and sail twist. In other words, gaffers have alot of heavy sticks and rigging way up high (right where you don't want alot of weight) and gaff rig sails tend to twist at the head (losing efficiency, especially when pinching). Running or reaching, a modern designed and constructed gaff rig should do OK against 'marconi' rigged boats.

Look into getting someone to design a carbon fiber mast, gaff, and boom (with appropriate fittings). You will also have to have a Nav Arch adjust the ballast (on existing designs) or else the roll rate will be too quick.

Ps: Get an old fashioned black powder cannon for your boat. All gaffers should have at least a couple of deck guns to repel boarders (and ring in the New Year). http://media5.hypernet.com/~dick/ubb/biggrin.gif



[This message has been edited by PugetSound (edited 05-28-2001).]

John B
05-28-2001, 03:50 PM
Any excuse,
http://albums.photopoint.com/j/View?u=1257037&a=9296204&p=48600914&Sequence=0&res=high
The gaff rig is less efficient on the wind than a bermudan. Answer... hit it with a sail area hammer, try to reduce forestay sag, make it high aspect( relatively).
In this seasons Logan series for classic boats We won 4 out of 6 races on handicap, got line in one of them, and saw our performance based handicap go from 770 to 831 over the season.Even when we were at 831 we got third. All of the boats we raced against bar one were bermudan and none of them are slugs.All of the boats we were finishing with were bigger than us, from 2' to 9'to (in Rangers case)19' longer.
It's caused a bit of a shock really.It's not supposed to be this way. We are staying with them on the wind and sailing away reaching and running.

Having said all that, hull form has a bit to do with your competitiveness and I don't know how IMS rates sail area.
You aren't going to put ali or carbon in are you ? You can get what you want from hollow timber spars. do you have a photo of your boat ? NEW boat too eh.

[This message has been edited by John B (edited 05-28-2001).]

Mike Field
05-28-2001, 10:47 PM
And to offset (somewhat) the disadvantages PS mentions --

-- the mast for a gaffer is lower, offsetting the weight of the gaff

-- the gaff itself can be hollow (although I don't think the mast should)

-- maybe you can rig vangs for the gaff, which you can't for the bermudan (although it suffers twist, too)

-- a bit of extra weight up top makes for a more comfortable roll, anyway.

I agree with the cannon, though.

Frank Wentzel
05-28-2001, 11:23 PM
I really believe, in the final analysis, that the Bermuda rig is the most popular only because of the racing rules and not because of any innate superiority to other rigs. The only true comparison I know of, using the same hull type, was done by Tom Colvin. He probably did it in the late sixties or seventies, he used a sharpie hull and compared the Bermuda, gaff, and chinese lug. Okay he was not truly unbiased, but no scientist is truly unbiased. In any case, he saw no advantage for the Bermuda rig. Why sacrifice performance on all other points of sail for a supposed advantage when hard on the wind. Heck, unless your engine is out and you are on a tight schedule, why go hard on the wind. That is when I get seasick – hard on the wind and into heavy chop - so I avoid it whenever possible.

Frank Hagan
05-29-2001, 12:39 AM
Michael Kasten does combine new and old techology with gaff rigs. He uses a single halyard for the gaff, rather than a throat and peak, to reduce windage and the number of halyards needing attention. He wrote me and included some details for my Gaff Rig Pages (http://users2.ev1.net/~fshagan/gaffrig.htm):

"One detail which may be of interest to you and your readers is that many of the gaff rigs that I've specified make use of a single halyard for the gaff. It is made possible by the relatively short gaffs that I prefer, arranged much like the gaff rigs on the Baltimore Pilot Vessels of the last century."

Here's a drawing of his Redpath, which has great lines to my eye. He combines hollow aluminum masts to reduce weight aloft with some creative mods to the rigging. On his schooners, he prefers a fisherman's stays'l to a gaff tops'l. More can be found on his web page at http://www.kastenmarine.com but be warned, he builds metal boats (they only look like wood.) Now if we can get him to design wooden boats ...

http://users2.ev1.net/~fshagan/redpath.jpg

I also just recieved a link of a modern designer specifying gaff rigs in England from Dean Wallis, who tells me the designer Ed Burnett worked with Nigel Irens when they designed the Westernman Gaff Cutters (info passed on just as given to me; I haven't had a chance to verify any of this.) Here's the links to his page (look especially at the 36' Rosebud): http://members.aol.com/hespj/rosebud/ and http://www.byd.btinternet.co.uk/byd-designs.htm

Alan D. Hyde
05-29-2001, 01:56 PM
Frank Hagan-------

"Redpath" does appear to be a pretty, and well-thought-out, design. Thanks for your posting.

What do you gaffers out there think of Kasten's thoughts on the fisherman versus the gaff topsails?

It's my impression that Irving Johnson, who knew something about schooners, might agree with Kasten.

Alan

[This message has been edited by Alan D. Hyde (edited 05-29-2001).]

Thad
05-29-2001, 06:22 PM
I mentioned this query to Deiter Empacher who works out of Marblehead and an office at the Dion Yard in Salem when we were talking today. He expressed some interest and the feeling that it could certainly be done. How you would place in the races would be the question you would be trying to answer.

Stephen
05-29-2001, 09:16 PM
Check out a book at your local library by C.J. Marchaj.
Also visit this Gaff rig site:
http://users2.ev1.net/~fshagan/gaffrig.htm

Phil Young
05-29-2001, 09:38 PM
I remember reading some time ago about a boat, probably a west epoxy creation, built to look very traditional above the water, nice sheer, traditional cabin sides etc, but was a sexy little racing rocket below the water. I don't think she was gaff rigged, but it sounded like a great concept. Left mouths hanging wide open every time she turned up at a regatta and ripped through the fleet. A nice high peaked gaff sail, maybe with a topsail, should perform not far off a fractional bermuda rig. Should be able to control sail twist, it can be done on big roachy mains with full length battens, which aren't that much different than a gaff anyway.

John B
05-30-2001, 12:30 AM
Hesp hops on the forum from time to time. He's got some great looking designs as the link Frank posted.

I believe that most people miss the significant feature of gaff rig when they assess performance. They look at the most obvious feature of it ( a great 4 sided mainsail) and lay all blame and problem at its door.
The issue is forestay sag and the wind range a sail is expected to stand in. yes yes I know ,a good sailmaker can cut the sail to suit....but what he can't do is cut it to suit a wide threshold like the modern boats.
We are going almost unbelievably well in the light, pointing up with the bermudans, but struggling when it breezes up, and that is because of forestay sag. Gaff twist is a non event( it can be dealt with without vangs), especially with the topsail set.

You put a gaff rig in a hull which will stand modern rig loadings, provide for plenty of gearing to pull on backstays so that the forestay tension is maintained by them rather than the mainsheet/leech/peak halyard and you'd be able to flake off the main and carry your sail longer without the typical reaction you get when you ease the mainsheet.( you ease the mainsheet , the fore and aft tension eases, the jib luff hollows and powers up the sail right when you are looking to depower).

Is it worth doing Foster.

I used to think going past someone on the motorway at 100mph and shifting into top was good. Sliding up and around some chrome and glass modern in 5 or 8 knots of breeze is the thing.Their faces say it all.How can this be happening?
Satisfaction guaranteed.

Foster Price
05-30-2001, 04:27 AM
Hello Guys

Looks like we're getting to the crux of it now. Yes I am thinking modern hull form (the big dinghy type, semi-planing, light displacement)with a fin keel so it can be lifting without compromising wetted surface, yet keep the weight low. (I need shallow draft to get up to the moorings here).

So the hull could be designed to take the rigging loads necessary to keep the forestays tight. The idea of real serious running backstays would take some swallowing but they're no worse than lots of the other bits of string we put up with on bermudian rigs.

Further we are not talking about building to the rule(IMS or other), only using it as a defacto target of what to achieve.

To take John's points a little further, what sort of compromise should there be between the headsails and the main in terms of area? If it will stand is a single headsail the best option or are there other reasons such as backwinding that encourage gaffers to use divided headsails?

Next, it seems that its a choice between a short gaff, and a long high peaked gaff that sets a topsail above, what are your thoughts here?

Much thanks for your head-scratching so far, this is a great place to learn.

Regards - Foster

BrianCunningham
05-30-2001, 11:40 AM
Sound like a good job for Nigel Irens

http://www.nigelirens.demon.co.uk/

I'm sure he'd get a kick out of it!

Phil Young
05-30-2001, 11:18 PM
Go to http://boatpoint.ninemsn.com.au Do a search under used boats using $30 000 to $35 000 and Gaff as a keyword. You should find a Young 780 sportboat, west system, which has been gaff rigged. Looks great.

John B
05-31-2001, 02:57 PM
What would be really interesting , would be to speak to the owner of that yacht. Young 780 hull. They're pretty fast boats but like all Jim Youngs' later boats they have fine entry's and narrow bow sections, so I would wonder how It reacts to the gaff rig running. My feeling is that it would tend to be more likely to broach or trip.

Smacksman
05-31-2001, 04:15 PM
The Old Gaffers Association is for the use and development of gaff rig.
Along with my 1850 Emma which goes like a bomb we have an Etchells 32 with carbon fibre gaff, control lines run below deck, fin and spade planing hull, etc and which also goes like a rocket. If you want to race then there are lots of very keen owners in the UK who try lots of ideas [ battened topsl's with a big roach, gaff spinnaker in addition to a main spi, .. ]
If you just want to make a point off the wind then any well set up gaffer on a good hull will romp past a tupperware bermudan.
As I posted yonks back, we had a race between class yachts, one bermudan, one gaff, same sail area, same hull. The gaffer won [just] each time.

Phil Young
05-31-2001, 07:25 PM
John B, you're probably right, I don't know what the centreboard or rudder looks like on a Young 780. In PNG I raced for a while on a 24' sportboat, maybe an Elliot, I'm not sure. Carbon fibre everything. Fastest we ever got to was 24 knots on a screaming reach. Every now and then when we put a big kite up we'd get into a big broach, mast in the water, centreboard out of the water. She'd kind of sit there for a while being dragged downwind until someone managed to let the kite halyard go, then she'd pop right back up and we'd be back in the race. With a long low rig rather than a short tall one a larger balanced rudder might not be a bad thing. But you tend not to run dead downwind anyway in those things, they get there much faster if you tack downwind, broadreaching with a big asymetric kite off the end of the bowsprit. Huge fun.

BillP
05-31-2001, 08:36 PM
Having owned a 42'gaffer and a few bermuda rigs, the gaff was harder to handle in rough ocean sailing. The boom is a lot of weight. Even when preventers are used they still don't make it as easy as the bermuda rig. Same in calms...the gaff is harder to control when rolling around downwind. Sail one before you build.

Bill P

Ian Wright
06-01-2001, 11:15 AM
Originally posted by Smacksman:

As I posted yonks back, we had a race between class yachts, one bermudan, one gaff, same sail area, same hull. The gaffer won [just] each time.

Ah yes,,,,,, sadly not quite every time. My gaff Vertue lost (just) to Rob Williamson's "Maid of Tesa" in a match race at Burnham in 1992 or 93. in my defence Patience was brand newish and Tesa was a well worked up boat.
We've sailed together many times since then. Some times he wins, sometimes I do. On a windy reach I'll win by miles. On a light beat he'll pull away. With enough wind to power us both up, there is very little in it,,,,,,,,IF I use my jackyard tops'l. After all we all know that it's a long mainsail luff that gets a boat to windward. Without the 14' of extra luff that the tops'l gives me I point 10 degrees worse than him.
,,,,,,,,and gaff rig LOOKS better,,,,,,

IanW.

Smacksman
06-01-2001, 04:36 PM
You're absolutely right Ian, gaff just looks the business. Ref. the match racing - I had in mind the races with Arthur Keeble in Chittabob on the Blackwater - forget who the other boat was. Rob lives just round the corner from me and I've raced against the 'Maid' on several occasions in the past. He, like other good sailors, have a knack of pointing the boat in the right direction which makes up for a lot of 'Maid of Tesa's' performance.
The other sail that pulls you to windward is a bar taught jib and this is where the modern bermudan scores with a standing backstay and no bowsprit. This allows awesome rigging loads to be applied in the quest for a tight luff. Frankly, loads like they apply now would fold up my 100+ year old boats like a venus fly trap or to be more up to date, like the America's Cup boat 'Young America'.
And Bill is spot on with the flailing gaff in a seaway. This is one of the reasons I break with tradition and have twin topping lifts located several feet forward of the clew end of the boom so that they act as lazy jacks as well. Hardening them up in a seaway traps the gaff between them, well a bit anyway, and tames the gaff a bit. I tore the leach once with a bad gybe - the gaff flew across while lurching into a hole and snapped the bolt rope and tore the flax across the panel [ a good reason for vertical panels - with horizontal panes I would have ended up with half a main] On one lumpy crossing we dropped the main to save it from a flailing gaff and set a jib on the mast sheeted to the boom end and with the regular jib and stays'l set, made slower but more comfortable progress.
Another trick I found running in lumpy but light conditions when the motion knocked the wind out of the regular sails was to drop the lot and set a light spinnaker. The lighter cloth [approx 1oz] set quicker after a good shaking and without the other sails blanketing it, the bag could be rotated by the pole about 120 degrees to catch the shifting breeze. It also kept the crew awake but I only did it in daylight - I'm too chicken to leave it up at night.
The other sail which is a dream to use off the wind in a good breeze is the square sail. The Brixham Mule 'Regard' [50'] has one and when fully braced, sets like a statue with no movement of the yard.

Bob Cleek
06-01-2001, 05:54 PM
Ditto to the gaff advice here. If you want to check out "state of the art" gaff rig design, look at the Laurent Giles website. They've been designing gaffers since God was a pup. They also have stayed on the cutting edge of sail design for some seventy years. Still, I see they are designing some incredibly beautiful gaffers now with current scientifically designed underwater profiles, but fantastic Edwardian traditional design above the waterlines. Word is they go like blazes. And, of course, their stock plans are available, including the Mother of all "state of the art" gaffers, "Dyarchy."

Ian Wright
06-02-2001, 09:39 AM
[QUOTE]Originally posted by Smacksman:
[B] Ref. the match racing - I had in mind the races with Arthur Keeble in Chittabob on the Blackwater - forget who the other boat was.

That would be Asti, another 6 meter? The OGA had an annual challange match against the Burnham Royal Corinthian YC on the Crouch. In six or seven races my Patience was the only OGA boat to lose against her bermudan sister. Shame! ,,,,,,,,but it was also a very light day. (note: second excuse) Other matches were between ECOD's and West Solent ODs.
Identical boats, but one gaff, one bermudan.

On the other hand when the owner of another East Coast OD "Nancy" tried to beat Arthur he came nowhere near him, one year sailing bermudan, the next gaff. But that only proves that Arthur was/is a terrific sailor,,,,,

IanW.

[This message has been edited by Ian Wright (edited 06-02-2001).]

John B
06-04-2001, 10:27 PM
Bill is pretty right about getting a roll on with a gaff rig. It's bad enough when there isn't enough wind with a bermudan rig. When the gaff starts to snatch as well... it creates a whip like action. We had a miserable few hours at christmas that way and I ended up contriving a shockcord arrangement to safe it up a bit.
There are negatives with the rig. Thats one of them. Range of wind without reefing compared to the moderns is the other and as I said earlier, forestay sag.
Highest performance gaff rig? (in a modern hull)( I didn't realise that you were talking about a new hull Foster)
I'd say sloop rig, high peaked gaff, really powerful runners, outhauls rigged for the gaff as well as the boom, overcanvassed in the mainsail.
Hull design... Well you've heard my theory on what a gaff rig does to a fine bow/ powerful stern. I'd say you'd look for something with equally powerful bow sections as aft. Elliot 1050 rather than Young 88 or 11, if you get my drift.

Smacksman
06-05-2001, 05:39 PM
I tried gaff vangs once JohnB and found them a nightmare. The slack catches in everything when hoisting and lowering and the angle of purchase when the gaff is up renders them almost useless.
If your mainsail leach is built strong enough to take the strain then a powerful kicker or boom strut might produce better results. Has anybody tried a really powerful boom vang/kicker [call it what you will] on a gaff main?

John B
06-05-2001, 10:40 PM
I don't believe that gaff vangs are necessary with the right geometry , Smacksman. Twist ain't a problem to us , and in fact I'm seriously considering getting rid of the traveller and replacing it with a centreline buffer arrangement ( very short traveller with rubber grommets or some other dampening method) so that I can promote some more twist on the wind. What I meant was an outhaul to trim the head of the sail. I've been wondering if it could be geared into the throat halyard so that easeing the throat would ease the head of the sail as well. It seems achievable fairly simply..... has it been done ?
The boom vang would have to work but the compression loading on the gooseneck......
Some serious thought would need to be given to that area.

Hesp
06-07-2001, 09:55 AM
Thanks Frank and JohnB

I'll just put in my two cents worth after experimenting with Hope and Rosebud.

Firstly, whilst it is right to concentrate on windward ability, don't overlook the outstanding reaching & running ability of gaff. This is a real eye opener for bermudan sailors.

Some potential problems with gaff are:

Excessive mainsail twist.
This is partly caused by gravity swinging the gaff downhill when the boat is heeled. A lightweight gaff and fittings help here, as does minimising the angle of heel.
Sail twist is also caused by the wind in the sail. A squarer sail with more sail higher suffers worse than a more triangular sail, hence short gaffs. I'm not to keen on short gaffs, the logical conclusion to short gaffs is a bermudan sail. A long gaff is needed for a decent topsail, and a decent topsail is a wonder to behold. Gaff without topsail is like pie without cream.
A POWERFUL mainsheet in conjunction with lightweight gaff will eliminate excessive mainsail twist.

Excessive weight aloft.
Use lightweight spars and fittings. Hope and Rosebud have all hollow spars, some carbon reinforced.

Jib luff sag.
Lack of tension in jib luff. If you fit a powerful winch on the jib halyard to tension the luff you will just bend the mast forward because there is no backstay to stop it. Instead running backstays are used, preferably with winches. Sometimes the windward jib sheet winch is used. Even winches aren't as powerful as a permanent backstay though. Again, a powerful mainsheet can help here, transfering tension from mainsheet to mainsail leech to peak halyard to head of jib. The rig needs to be designed with this in mind.
Large jibs as seen on bermudan sloops might cause an uncontrollable amount of sag on a larger boat, a good reason (amongst many other) to go for cutter rig. Also a sloop with its headsail on the bowsprit will either have no forestay to the stem, or will need walking round each time the boat is tacked.

Gaff swinging to and fro in a swell.
Again, a lightweight gaff is less troublesome.

Needs (usually) two halyards to raise mainsail.
On Hope I fitted peak and throat halyards with the same purchase. The gaff is light enough for me to pull the sail up grasping both halyards at once. The gaff goes up level, the throat halyard is tensioned, then the peak halyard is pulled up the rest of the way and tensioned (with a crease from peak to tack, this will disappear when the sail fills).
Again the lightweight gaff scores.

Attracts excessive attention.
I really don't know what to do about this.

Note that success lies largely in tensioning the rig. This will not work as well, and might cause damage on old/carvel/clinker hulls. The hull will bend as tension is applied. I believe many of the percieved faults of gaff rig are in truth because of overweight/worn out/unsuitable hulls.

My list for a succesful gaff rig would include (not in any order):

Lightweight gaff. Essential. I've used a hollow rectangular section (stiffer than round) wood gaff sheathed in carbon fibre.
Light spars. But not as extreme as the gaff.
A jib with long luff but moderate area - high aspect.
A constant line of tension right over rig - stem at LWL/bobstay/cranse iron(end of bowsprit)/jib luff/mast band at head of jib/peak halyard/gaff/mainsail leech/end of boom/mainsheet/deck.
A stiff hull to take the above tension.
Good looks.
Low stretch rigging. Kevlar or rope/wire halyards.
A good sized topsail.
A powerful mainsheet. I tried a centre mainsheet for a couple of seasons. This was on a track right across the deck. This allowed the mainsheet to be tight reducing sail twist even when broad reaching. In itself it was a success, but was complicated and put a frightening bend in the boom.
Winches for jib sheets/runners (on boats over about 24').
On balance I prefer the pole mast (head of topsail goes to top of mast). The topsail has no spars so is easy to set/stow. The jib has a longer luff. The peak halyard is attached to gaff at near right angles giving a more effective pull.
Cream sails.

I could go on, but I'd better stop.
John.

[This message has been edited by Hesp (edited 06-07-2001).]

John B
06-07-2001, 11:02 PM
The bit about the peak making a right angle with the gaff is a subject close to my heart and in my opinion, the single most important way to make a gaff stand well to windward. This is the “geometry” I was referring to earlier. You achieve this by the length of mast between the throat and peak halyard being about 75% of the length of the gaff. Simple . It works. It’s a good thing. When reefed the thrust forward of the gaff is lessened or negated. I believe that my rig is under as much or more stress in 15 knots than in 35 knots reefed. Certainly I feel good when I wander up when it’s blowing, look upwards at the saddle , and note that it’s floating gently around, and the mast is nicely in column. No undue stress trying to make it jump sideways.

John B
06-12-2001, 04:02 PM
Ah, finally got access to photopoint.......This is 1 reef in, but you get my drift about the peak attachment point at the mast making close to a right angle.
http://albums.photopoint.com/j/View?u=1257037&a=9296207&p=33309903&Sequence=0&res=high
2 reefs in and the throat halyard almost becomes redundant.