Bristol Channel Cutter

[Mike Meer]

Hey fellow sailboat enthusiasts.

I am working on a Bristol Channel cutter for an owner who is considering many options in spar material. The rig plan calls for a traditional gaff rig and he would like to keep it very traditional, saddles and rings are in the design brief. My thought would be to go with wood-painted carbon fiber all around. Forespar says they can build carbon spars in the shape specified by the design. I'm worried about the paint being rubbed off by the gaff saddle and the sail rings. Justified? Mybe a wood mast and carbon boom/gaff?

Also, what do you think about hardware? The traditional way to go would be bronze throughout. We could also do dyneema lashings in a traditional marlin spike application for allot of it.

Mike....

[Bott]

Just my initial input:

There is basically nothing to be gained from a carbon boom on such a boat. In fact, a solid wood boom (with is inherent weight) is generally a positive addition to the sail set, naturally eliminating unwanted twist in the main.

As for the gaff, there are many good things to be gained with a light gaff. But, depending on the cut of the sail and the location of the peak halyard points, a overly bendy can affect the set of the main greatly. This can be either good or bad, depending on weather you are embracing this affect or not. I believe big gaffers in NZ use more flexible gaffs to allow them to flatten and depower their mains substantially. Though, I imagine this has to be accounted for in the sail cut as well. Its a complete (and complex) system.

[Brion Toss]

Hi again,
We had the pleasure of making up Vectran standing rigging for a Nigel Irons schooner not long ago. Bronze deadeyes. I don't know how they handled the luffs, but the masts were white painted carbon fiber. Look up "Maggie B", and see if you can find some useful photo's.
A wooden mast, hollow birds-eye, would be simple and cheap -- and the grain wouldn't rub off. Then could save weight where it mattered, with carbon fiber gaff and topmast.
As for the boom, hollow wood, with gaff peak angle doing most of the work in limiting leech twist.
It's hard to put a vang on Lyle's booms, but you might try it. Keep that boom down.
Fair leads,
Brion Toss

[Brian Duff]

A well designed gaff saddle and luff lacing instead of hoops, leather or lacings over the hoops, can help protect the finish on ANY material of mast.

There is a huge benefit to be gained on reducing the weight aloft and in the ends of any boat, but in particular in a boat which already has a reputation for stopping due to hobby horsing and a cruising boat which may actually one day get caught out in real rough weather with a need for high performance and no RC to provide immediate support.

Using heavy materials like bronze for anythign is a bit contrary to the idea of using carbon. If carbon is chosen, go the whole way, aluminum or titanium anywhere hardware is ABSOLUTELY needed, like chainplates or stem fittings, anchor rollers and other attachments - use lashings, strops etc where ever possible.

A boom vang is a geat benefit to any boat, gaffers in particular. However it is likely they wish to store a dingy on the cabin top so nix the boom vang, but be sure to rig up topsail sheets to each side of the gaff so that he can control the peak on all points of sail to get the best shape, stop swinging in light rolly stuff, and fight chafe by holding the gaff from getting bound by the lowers..

[Brion Toss]

Hi Brian,
I mostly agree. But I don't think that bronze deadeyes are undesirable here, considering their location. Still, I only mentioned it as something we put on a (very fast) schooner; I like Colligo's aluminum deadeyes. Keeping weight out of the ends, and down low is what matters most.
I believe when you say "tops'l sheets" you actually mean gaff vangs, to limit leech twist. While an ancient and effective tool on some boats, it might prove tough to use on a BC 28, given the angles that would result. Worth a try, but reducing peak angle and gaff weight would accomplish the same task more easily.
And yes, a good gaff saddle, like the one that Port Townsend Foundry sells, would be preferable to jaws. So would a sail track, though that would require some skillful design and machining.
Fair leads,
Brion Toss

[Bott]

Originally Posted by Brion Toss

But I don't think that bronze deadeyes are undesirable here, considering their location. Still, I only mentioned it as something we put on a (very fast) schooner; I like Colligo's aluminum deadeyes. Keeping weight out of the ends, and down low is what matters most.

Yeah, that confused me too. This is a med-heavy displacement boat and going for Ti or Al parts at deck level seems pretty needless. Up high, a few pounds here and there can make a huge difference, but on the hull, especially on a BCC it's incoherent.

Also, there is little need for a typical boom vang on the gaffer for sail draft control (there are many more tricks for this with all the other string and that sort of control makes much less of a difference on the low-aspect gaff sails vs Bermudian shapes), but for boom control a kicking-strap from the boom to the bulwarks can be of great use.

Anyhow, my $0.02. worth all paid.

[Brian Duff]

The wording topsail sheets was entirely intentional, and they are very effective tools for controlling the gaff when sailing.

I started sailing gaffers on boats with no topsails, and we carried just one vang, this worked well, even on boats with very find sterns. They were not used so much to control twist ON the breeze, as when off the breeze. It also served very well to keep the gaff from resting on the leeward lower shrouds when sailing deep, and leveraging the jaws to breakage (of course for this rig we are talking saddles, but the loads will still build as the gaff tries to bend over the lower shrouds) , allowing the boom to be eased much further than with no vang. Later, sailing boats rigged for gaff topsails, i learned to just use the topsail sheet as a vang, and also as a good tool to control the gaff end when lowering the sail. It occurs to me now that having two topsail sheets one each side would allow both the use of the 'vang' even with topsail set, and also the ability to both vang and preventer on the gaff in particularly demanding situations. This gear needn't be left rigged all the time, as some passages are done with out the intention to sail deep, some in decidedly heavy conditions, and others where every control will be needed, along with every sail, to get there fast and safe. The twist of the sail up wind is controled like Brion mentioned, through design and weight, sail design and also peak halyard tension , and sheet lead.

I thought the idea of using bronze only for the lower deadeyes and nowhere else a bit odd, when aluminum provides most of the benefits of bronze at a lower cost and weight, correct?

reducing weight on a boat make a load of sense, anywhere you can do it. Maybe aluminum and titanium can make for more beer capacity?

Why buy the wrong stuff when for the same basic cost or just a little more you can buy the right stuff?

Or you could just use Garhauer, Profurl and Z-spar..... and have a boat just like the one next door, the one that never goes out sailing...

[dwkentsr]

This thread refers to my BCC, Rose. I am rebuilding her after she sank in hurricane Ike at the Galveston Yacht Basin. The sitka spruce spars are under construction in Port Townsend; the mast will have hollow sections but the boom and gaff will be solid. I like the Colligo deadeyes and the weight savings aloft afforded by the Dyneema. However, if I stick with stainless steel wire for the upper and lower shrouds, bronze turnbuckles and bronze chainplates that extend below the water line, I will have a lightning ground system?

To minimize weight in the rigging running back stays and fore stays will be Dyneema with Coligo ends and aloft I'll use bronze cage blocks. How to attach the runners on deck is less clear to me. They have to be easily accessed on the inside of the bulwarks so deck mounted pad eyes might serve better than chain plates. The leads will be fair to the self-tailing jib sheet winches but not rely solely on them. I think they should be on a 3 or 4 part purchase and secure to a cleat or a cam cleat.

Your thoughts or comments appreciated

David Kent
http://www.bccrebuild.blogspot.com

[o0dunk0o]

David

For your runners i would suggest a tackle hooked to a chain-plate with the fall leading from the uppermost block down to a block on the deck which gives you a fair lead to the sheet winch.

I regularly race a 36' gaff cutter which has this arrangement, the tackles we use are 4:1 and it works very well, although for your boat a less powerful tackle might be more appropriate.

The backstays attach to the chainplates with simple hooks, so when running downwind it's easy to unhook the stay and move it forward clearing the boom and mainsail.

[Brion Toss]

Originally Posted by o0dunk0o

David

For your runners i would suggest a tackle hooked to a chain-plate with the fall leading from the uppermost block down to a block on the deck which gives you a fair lead to the sheet winch.

I regularly race a 36' gaff cutter which has this arrangement, the tackles we use are 4:1 and it works very well, although for your boat a less powerful tackle might be more appropriate.

The backstays attach to the chainplates with simple hooks, so when running downwind it's easy to unhook the stay and move it forward clearing the boom and mainsail.

I agree, except I'd leave off the upper block, and just run a continuous runner to the winch. Plenty of power there, no block waving around at head height, much quicker casting off and taking up, no need to unhook anything.
Fair leads,
Brion Toss