sail track on a gaff rig

[mic]

I'm going to be rigging my boat as a gaff cutter and want to do a nice varnish job on the mast, but in order to minimise the maintaince of the varnish, with it constantly getting rubbed by the gaff jaws and hoops i'm trying to find a way to put on a sail track or gaff track (hmmm, new word) or somthing to achieve this. Any help in this matter would be greatly appriecated, has any body here managed to achieve somthing similar?

[rbgarr]

How long is the hoist on the mainsail, i.e., the length of the luff from clew to throat, where the gaff starts on the mast??

[qm]

Paint and wax the mast

[Bob Cleek]

Generally speaking, it cannot be done. Figure the gaff rig has pretty much reached its highlest level of development possible and nobody's done this yet. Go figure.

Now, it is possible to use sail track to fasten the luff on a gaff sail (but who'd want to), but you cannot use a track to fasten a gaff jaw gooseneck, really. The problem is that the weight and stresses on the gooseneck would soon rip any track right off the mast. You could try to rig some super throat fitting, but how would you get the gaff up and down from it?... (Although you may wish to review the rig of the somewhat unique Thames spritsail barges in this respect.)

The usual way to deal with gaff jaw chafe is to place protection on the mast where the jaws bear. (Some even go so far as to do the same at each reef point!) Originally, most used a sheet metal collar to prevent the mast being bruised. The problem with this is that the tacks holding it on can promote rot and ruin the mast. In recent years, many are running a collar of dynel or glass and epoxy, faired smooth to the spar. This can be repaired and replaced and is practically invisible, but gives good denting protection.

If you really want to preserve your mast, use a gaff saddle rather than jaws. The leather padding on the saddle and its shape will prevent any problems with denting.

As for your luff, I'd go with lacing hands down. Parrels can and do often bind and they will wear a mast pretty quickly. Hoops less so but still do. Rope don't.

[Ian McColgin]

A rare moment for me to disagree with Mr. Cleek. It can be done, is all the time, at least in smallish sizes like the Wianno Senior. The main is about 300 square feet and the gaff peaks up to about 60 degrees.

The gaff imparts considerable compression loading. Jaws are the simplest way to handle that as they will always take that load dead center in the jaws and normal to a tangent to the mast at whatever angle the gaff is flying. This load is never perpendicular to a track.

Three factors must be combined to engineer a gaff's track gooseneck correctly.

Firstly, the track must be up to the strain. On the Wianno Sr, the section of track where the gaff will land is not conventional track, but rather a pair of stacked bronze bars, outer one wider giving a stronger albeit heavier structure than the rest of the track. This has to be fitted carefully to allow the gaff's slide to get onto it. The Seniors have solid masts and this part of the track is mostly held with longish screws and a couple of through bolts that can line up with fittings on the fore side of the mast.

By the way, the Wianno's track is considerably wider and closer to the mast than the off-the-shelf tracks you'll find in normal chandelries. You'll likely need to create your own track and slides for the sail. On the Wianno, the slide are biggish rectangles with one small end partly open.

Secondly, the verticle pin for the side to side pivot point of the gooseneck needs to be as close to the slide as possible, to minimize the leverage arm of the compression strain. The whole unit needs to be very robust.

Finally, a good high peak angle helps. I'd be loathe to try a gaff on slides with a 45 degree angle. By the way, when I mentioned the Wianno peaks up about 60 degrees, that's above horizontal. The angle subtended between gaff and mast is thus 30 degrees.

Wiannos are raced in fairly boisterous winds and are fameous for not even having reef points. The most common gear failure is spinnaker pole, followed by gaffs. I've not happened to hear of a gaff gooseneck failure and know of only one track failure in that area, entirely the owner's fault for overlooking several years of developing rot.

If you're talking a really big main, like over 500 sq ft, it could be that the engineering requirements would be hard to meet.

I don't know that the complexity will justify saving a little work in varnishing.

[rbgarr]

Ian, the Wianno's rig is what I was thinkng of recommending when I asked for the hoist dimension. I agree with you that I've not seen it anywhere else and that it's well engineered for the demands and design, but a lot of trouble to go to just to have an 'unblemished' varnished mast.
Copper banding in way of where the gaff jaws bear on the spar would be another alternative. The masthoops didn't create a lot of wear as far as I could see on my Beetle cat.

Info on the Wianno Senior can be found here:
http://www.wiannosenior.org/

[ 01-16-2005, 09:29 AM: Message edited by: rbgarr ]

[ssor]

It looks like genoa track might be robust enough to support the gaff. Any method that does not apply the load normal to the center line of the mast will complicate the engineering math.

[Don Kurylko]

Check out the Spice Island Cutter in “Yacht Designs”, by William Garden. It’s rigged with a gaff on a track and has many nice drawings of hardware and details that may be useful. But also consider that many of the virtues of gaff rig are compromised with this type of system – mainly being able to raise and lower the sail easily OFF the wind. The slide system will surely bind, as it does with Bermudan rig; not to mention the increased cost and unnecessary complication.

Cheers,
Don

[Bob Cleek]

"The main is about 300 square feet and the gaff peaks up to about 60 degrees. ... This load is never perpendicular to a track. ... Finally, a good high peak angle helps. I'd be loathe to try a gaff on slides with a 45 degree angle."

I agree. Sorry to disapoint you, Ian! LOL

There ARE designs which carry the gaff well peaked up. These CAN get away from the usual limitations of a gaff boom, but only with particularized track design and construction. I wouldn't consider these boats conventional "gaff" rigs, although they surely are. But in some ways, they are transitional rig designs that bridged the gap between gaff and jib headed sails.

Even with a beefed up fitting, if the gaff is carried in such a way that it will fetch up against anything if swung forward (even the point of furthest travel at the neck), as soon as it fetches up, the momentum is reversed: the obstruction (usually a shroud) becomes the fulcrum of a lever carrying the forward force of the boom. What it is lifting is the gooseneck directly aft, possibly pulling it off the mast. No?

[mic]

Yeh sorry guys, i should have given you all some more info. I've posted photo's of the boat on the forum before but here's some pic's again just for those who havn't seen them.
http://www.imagestation.com/picture/sraid43/pe1c33b2084a49ae40aab48c88e24ecf7/fce27b81.jpg http://www.imagestation.com/picture/sraid43/p4b9e52d99c8c0acdc3e2af1ad1882424/fce27ac2.jpg

The new mast is about 1.5m or 5' taller than the one pictured, although it's keel stepped it's still about 33' high from the top of the deck. There's a bit of an argument about the boom and gaff length but minimum boom length should be about 20' and a bowsprit of about 9' should poke out from the stem. Thanks again.

[Ian McColgin]

Nice picture. Sure hope you've good NA advice on the conversion. I'd be tempted to add a spanker abaft the house.

Anyway, I think this is too large for a conveniently engineered gaff gooseneck on track. It would be a huge pain, even a hazard, to strike in a violent blow.

I personally don't like coppering the mast in the way of the throat as you can all too easily get rot under. Thin oak or teak strips let just a little way (1/32" or so) into the wood and standing 1/8" or so proud of the mast should do the trick.

G'luck

[Andrew Craig-Bennett]

I agree with Ian, on both points.

[PVanderwaart]

For completeness, I'll point out that the LHF Meadowlark has gaffs running on a track, but it's a lightweight compared to the boat under discussion and not really relevent. I'm pretty sure that an off-the-shelf (boom) gooseneck could serve for a gaff if you can solve the track problem. I would worry some about it jamming aloft, though.

I think you are going to a lot of trouble to save wear and tear on the varnish. You will probably have to re-varnish the mast at about the same interval, and the trouble of putting on a couple of extra coats is less than the trouble of varnishing around the track, let along removing the track. Perhaps some extra attention to the hoops and gaff jaws would pay bigger returns.

I disagree with the view that the gaff has been honed to the highest possible state of development. I think that much better hardware designs, including tracks and gaff goosenecks, are possible, even obvious, but the market is too small to support the investment to make them. Too many people who sail gaffers are interested in something like historical reproduction in fittings, if not in cordage and sailcloth.

[MAGIC's Craig]

Here is an example of a 395 sq.ft. gaff fores'l on a 1-1/4" sail track. The track becomes 1-1/4" "T" track (genoa track) at the upper end in order to better handle the thrust of the gaff when fully hoisted and at the first reef. The gaff rides to a car, similar to the one shown in Bill Garden's book which has an upper and lower roller (horizontal pins) to bear against the track.

Still going strong after 15 years and some thousands of offshore miles. ;) It really can be made to work and it does save wear and tear on the varnish

http://www.imagestation.com/picture/sraid81/pc6e01d490776c78d676afdbc4ea5d633/faef94f0.jpg

[Matt J.]

Well RARUS's main is gaff rigged. No track, leathered jaws, and strips of fir embedded into the main mast where the jaws typically rest (flush at the ends, protruding mid-height about a 1/8 inch). There is no appreciable wear on the main mast from her gaff jaws. And it is a highly finished varnish (or it was, before some ass splattered white paint on it from his work boat, and it is again).

[ 01-17-2005, 02:17 PM: Message edited by: Matt J. ]

[mic]

Hmmm! certainly a lot to think about, I'm tending to agree that perhaps it's all to much work just to save a little varnish. Although lacing the main to the mast sounds ok, i can't see this rubbing to much. I suppose the big advantage of having a sail track is that as well as not having jaws rubbing on the mast i'd like to mount the radar unit sort of 3/4 of the way up the mast and anything wraped around it would snag on the unit. I mean the whole idea of going gaff rig in the first place was to bring a larger sail area lower down. Maybe a bermudian rig is going to be the way to go, less hassle, any opinions.

[Ian McColgin]

Mounting the radar above the throat would work but you might be getting a bit cramped with the radome obstructing the peak of the jib.

Another reason to stick a spanker abaft the house.

Do you like the height of the radome now? It looks about good for a yacht. Get up too high and you loose close in definition for a doubtful gain in theoretical range. I'd think a radome on a spanker mast sould end up just about that height. Something to be said for a much shorter run of the cable as well.

The spanker will be a nice sail to hold your head up at anchor or doing any anchoring or sail change evolutions where you want the boat to lie still. It's boom will make a nice derrick for scuba gear and such. Add ratlines to the shrouds for a quick view aloft.

G'luck

[Matt J.]

Our sails are laced to the gaff and the main mast.

Previous owner showed me how he was taught, and it seems to work great; takes only just a little extra care raised sail as we have mast mounted cleats for the throat and peak halyards, but we're talking an extra 3 seconds. The small line holds the luff well and does zero damage to the mast while allowing a natural sail shape. I wouldn't change it for anything else I've seen.

You'll get more sail area for a given mast length with a gaff sail, wouldn't you? It'd also look more "right" to my eye, IMOO.

[Magwitch]

I've seen a Francis 26 with a 'modern' gaff rig including a track on the mast. loads of very expensive Harken gear. It nearly worked. If you insist on going that way then Good Luck,,,,,,,
Better inmo is the traditional way, a well leathered gaff saddle or jaws, a lacing or hoops and loads of vaseline for lubrication.
Never a good idea to re-invent the wheel and more so if you fancy that the wheel should be square.

Ianw

[George.]

It seems to me that the reason for a gaff track would be better windward performance - sail closer to the mast, no gap, and all that. Only makes sense with a very thin mast, thin shrouds, a high-peaked gaff, backstays, and all the other garnishings of a racer - in fact, a bermuda rig makes even more sense!

If the issue is protecting mast varnish, I'd say go with lacings. I have them on Dalia, they stretch to let the luff shape itself naturally, give no trouble, and do not damage the mast at all. As for the gaff, wood jaws with leather, lubricated with carnauba wax (bet you Northerners will be jealous of that one :D ). Some hardwood strips glued to the mast where the jaws normally bear, and we don't reef often enough to worry about the reefed positions.

Then again I have never had hoops or a track on my own boat, so I could be wrong...

[ssor]

As for the gaff, wood jaws with leather, lubricated with carnauba wax (bet you Northerners will be jealous of that one )

Good hard tallow works fine and can be had as the residue of a nice beef rib roast.

[Chris Coose]

The only time my varnish got scratched was when a tack in the leather on the jaws got loose.

I've never used a lubricant.

I've got a classic cat with a high angled peak.

[mic]

It's not so much that i'm not happy with the height of the radar now it's just that i want it off the wheelhouse which i've now repainted, here's some pics!
http://www.imagestation.com/picture/sraid58/p2ea3f121e8f5a3d604be3dd31607576f/fc6654a8.jpg
http://www.imagestation.com/picture/sraid58/p1409c78d8d56a1cb1b3a66f5872b953f/fc665848.jpg
If i put the raydome back on the wheelhouse it stops me putting on a larger boom or perhaps a tender. It just looks crappy. So Ian what you're saying is to rig the boat as a gaff ketch instead of a cutter, oh sorry, a gaff yawl, yeh ?

[Jeremy Burnett]

If you lace it,which I think is the way to go, make sure the lacing is done backwards and forwards across the front of the mast rather than in a spiral fashion that causes binding when lowering. Use a hardish plaited rope and put some grease on it.

[Ian McColgin]

Much depends on how far back the new boom will come. I'd not anticipated it going abaft the aft end of the house. If so, you could use that nifty sampson post as the base for a tabernacle - have robust pivot points clear the mast heel flanges and you've still got a perfectly good sampson post.

I used the term 'spanker' rather than 'mizzen' to emphasise that it's a wee sail - yawl sized rather than ketch sized - and probably triangular rather than gaff. It's more a steadying sail, derrick and a good stick for the radome. Given the small size, I think you can forblock it against the house roof and not need quite so much lead in the forward shrouds.

If the boom ends up abaft a safe stance for furling or attaching the sail cover, there is a solution. Keep the first and second reef outhauls rigged and controlable at the boom near the hallyard. As you strike the sail, trim both outhauls. That will get the sail to lie down neatly along the boom and you'll not need sail stops out there.

For the sail cover, keep a bit of a tag line that passes around something well out there - perhaps a ring on the end of the topping lift. The sail gets small rapidly out along the boom, so you should be able to make a cover that can be buttoned on the bottom will still tucked up not all the way out. Then bend the tag line on a cringle on the upper back end of the sail cover and haul 'er out.

Beats hanging out wobbling over the dark and briney.

G'luck.

[mic]

Hmmm, never thought of a twin masted rig could look pretty sexy though, also solves the problem of staying the mast aft. Running a wire from one mast to another! I'm just not happy about using the sampson post as a mast support, not for any structual reson though, but because i wont have a sampson post and it might not look that nice, besides, it'll muck up my varnish job!
http://www.imagestation.com/picture/sraid44/pf53b93d5bda477f770295210c3a62977/fcdd9b8d.jpg http://www.imagestation.com/picture/sraid44/p4e732b61f65a9048a56d3bec28f0d5cd/fcdd98b9.jpg http://www.imagestation.com/picture/sraid44/p64970dba637c5acbce995ce046a4b79e/fcdd9a4c.jpg
i suppose i could just step the mast into the dead wood aft of the sampson post like a yawl any suggestions

[Ian McColgin]

Truely using the sampson post as a tabernacle would hide some of the varnish - by no means all - but the post would remain useful. Perhaps more useful than putting the mizzen abaft it.

The mast would have flanges coming down either side to embrace the sampson post, shapes such that they stay inside of the rounded corners of the post and have rounded outer edges themselves.

The pivot would be larger than normal - maybe 1" or even 1-1/2" diameter rod and stick out maybe 4" on either side.

With the mast up to use the post, pass a bight from the side opposite the prevailing load around the fore side of the post and caste it over the ear opposite. The rest you can finish off with a couple of figure eights on the aft side.

Or maybe use the sampson post location as a proper mast step - looks like it goes down to the horn timber anyway - and set up the sampson post in a new location just a bit aft.

G'luck

[mic]

Thanks again everybody for all your input it's been great. smile.gif

[ssor]

Mic,
Check out Dynamite Paysons method of lacing a sail to the mast. It is a bit odd in that it pulls taut when fully hoisted but goes quite slack when you drop the sail.