BYYB Forums

I've been working on a classic design and it's details. I want the look and feel of a 19th century craft, but not the slack stays and shrouds.

This is a shroud or stay termination at the deck. It's used in place of the typical turnbuckle and chain plate. Lets face it, turnbuckles and chain plates don't have the look and can snag things, especially during tacks.



The chain plate is replaced with an eye bolt which goes down through the deck and a carlin or deck beam. On my design it goes into a blind nut, set into a side deck beam, but it could be just through bolted with a suitable backing plate (like a big old hunk of thick plywood). To adjust the shroud or stay tension, you just turn the eye bolt in (tighten) or out (slack).

The wooden thimble part is made of two principle pieces, the body and a center section (slightly darker color shown). The body has a cutout so the eye can be placed over it as it's assembled and the center section keeps it from being compressed and breaking. It's held together with machine screws (little bolts, but with a screw driver head). The bolt holes are bunged and everything is pre-shaped. An exterior groove to accept the rigging wire, a chamfered hole for the eye, rounded corners all to suit style and craftsmanship of choice. I think the body will look better if it has some shape to it, as seen in the side view, where the middle is slightly fatter then the ends, of course the tear drop shape in profile.

The wood needs to be fine grained and dense (consider it's job). Good choices would be white or live oak, hackatack root, locust, lignum vitae or other very hard, dense wood. Teak is too soft and crumbly so is mahogany.

The center piece needs to be vertical grain, but the body can be quarter sawn stock.

This is basically an adjustable chain plate, which eliminates the turnbuckle, all of it's related parts (thimble, fork, clevis, eye, etc.) and the chain plate itself. Because the eye and wooden thimble can move independently of each other, mis-alignment is tolerated without bending a turnbuckle or chain plate and raising or mast lowering operations will not bind up this assembly, like it can a turnbuckle/chain plate arrangement.

The same technique could be employed for deadeyes too. A faux dead eye can be made, but it's lashed or hard mounted to this eye, instead of a chain plate. Rather then adjusting the deadeye lanyard for rigging tension, you just screw down the eye a little.

To dress up the swages, wrap some black rigging tape around it, making a taper from the top of the wooden thimble to past the swage. You could also use whipping thread to do the same thing, both will hide the crimps and pretty up the thimble.

It wouldn't look as good if you used bull dogs (wire rope clamps) to seize the wire around the thimble. I always crimp the wire, but many don't have a proper swaging tool. A quick note, the two metal bars with bolts that get tightened, isn't a swaging tool, it's a safety line crimpier and not suited to rigging wire. It doesn't provide enough pressure nor in the correct locations to be trusted to swedge rigging wire (I've seen them fail). A real swager is a costly tool (mine cost 350 bucks), but I do a fair amount of re-rigging each year, so it pays for itself eventually.

West Marine or the local marina can swedge stuff for you, but you have to bring it to them and watch what they're doing.

Food for thought . . .

Ahoy Paul,

Great ideas!
Enough to turn any nautical head.
By that I do not mean toilet; I mean the head of a person, the mind, the attention, the look, but not the toilet paper.

Thanks, Paul!

Greetings Paul,

I like the look of the thimble. I'm guessing that the great expanse of wood you have on that teardrop shaped thimble would be just screaming for some fancy inlay work or a carving ... maybe a facing "R"s logo ...

Three questions come to mind.

(1) Does the cable twist that results from twisting the eye-bolt to adjust shroud length have any effect on the performance of the cable.

(2) Is there a locking nut to prevent the twisted cable from trying to un-adjust the shroud.

(3) Holy bucket of eye-bolts, Batman! hock: Where ever do you find eye-bolts that large and just how many sawbucks do they set you back? Or does that nice welder you know just hammer them round and weld them up for you in her spare time?

Cheers,
Tom

Tom, the fancy welder I know is my other half, who is a far better welder then I, though I can beat some round bar stock into a loop and weld it up, I usually buy them at Ace Hardware.

The drawing is a bit out of proportion. The size is determined by the eye you find. I can get good quality SS (316) eyes from 1/4" to 1 .25" inside eye diameter.

The center section and thimble length is calculated by the inside diameter of the eye as it has to slide over the one side of the thimble. There are two styles of eye, forged and wire. The wire type are machine bent around a form and the eye isn't completely closed. These are the light duty versions, though most more then able to tolerate what these boats can toss at them. The forged eyes are the bee's knees with an enclosed eye and much stronger. Some can be had with a shoulder, but that's not what you need here.

Cable twist can be handled with a swivel at the attachment on the mast, though most cables can accept some turning, especially if with the "lay" of the wire.

With a swivel, you don't need a lock nut, but it's a good idea. The eye bolt uses two nuts, one below (I use blind nuts so I can just turn them from above without help) and a second on the weather side. This is backed off, then the eye/thimble assembly turned to the desired tension. The second nut is then tightened down against the deck, locking it in this position.

I often make blocks, special cleats and these type of "decorative" pieces. Many will have my double R logo on them, but there are other options, like a cool looking coin placed over the axle of a block or a small brass medallion with the boat's name on it, let into the surface of the thimble. Lots of options here.

Good to see your post Jim. Depending on my activities on the particular day, the one that must be obeyed may suggest that I am often much like the contents of a head from time to time.

Paul...I am nearing completion on my weekender and I am considering the "eyebolt" through the deck idea instead of the chain plates bolted to the side of the boat.

This is my first build and I am new to sailing so I have no idea as to how much tension gets placed on those shrouds. My question is how "beefed up" should the deck be to accomodate the tension the eyebolt will be under?

I look forward to your feedback!

It depends on where you manage to put the through bolt hole. If you're good, you can hit the sheer batten, drilling through it. This is asking a lot for a "blind" drilling operation so it would be best to provide a doubler on the sheer batten and additional plywood (as a backing block) on the underside of the side deck. Drill the hole perpendicular to the deck angle. Use a good length of 1/2" plywood under the hole (maybe long enough to hit both chain plate locations) and fit a 1 x 2 or 2 x 4 doubler against the sheer batten. With this new material glued and screwed in place re-drill the hole in the deck, using it as a guide to keep this where you want it, through the new stuff.

If you're an average sailor and run for shore when the winds continues to gust over 20 knots, then a little plywood and a batten doubler will get it done. The loads aren't particularly heavy, but your eye bolt should have at least 1,000 pounds breaking strength. These shrouds just hold the mast in column and resist headstay tension when close hauled. Get as long a bolt as you have room to adjust under the deck.