Chain plates on Giulietta, interesting design

[Giulietta]

I was talking with JRP about chain plates, and decided some of you would like to see how interesting the design of the chainplates on my boat is...it's really cool, take a look.

It's a well engineered system that transfers all mast / Shroud loadings, thru the deck, pass the hull sides, into the boat's keel structure, where the reinforcing grid bears the stress, instead if bulkheads, or the boat's sides..

This system is rather light, extremely resistent, and sperads load over an enormous area, allowing the boat to sail harder and truer...less bending effect and deformations...it allows me to sail with confidence in any winds...

The bellow drawing shows a front view of the Kevlar reinforced beams or stringers.

Attached to the Kevlar stringers, there are on each side, Satinless steel plates, that reinforce the zone



The below drawing shos how the 3 stringers are laid (not to scale), and how the SS stud goes thru the 3 pieces.



The bellow photo shows the stingers being made and some already in palce (black arrows)..



and bellow photo shows the above deck plate, that transfers the load from the shrouds to the beams under the deck



This to show you that a well engineered system, on a race boat, will in fcat rival or be stronger than the "over beefed up system" of hevaier boats, ocean goings and old shoes.....

agree??

[knothead]

It's a beautiful design and installation Alex.

Even though I have a very simple type of boat and chainplate setup, I appreciate the elegance of a well engineered system like your.

Something like that would be pretty unnecessary on a boat like mine though.
It would be like a having a B and R rig. Not necessary, overly expensive and out of place.

[bubb2]

Ales, I don't want to offend you! But it looks very much like the Beneteau tie rod system.

[Giulietta]

No offense, Beneteau is a good boat...

The system is different, as the BEneteau rod is long an attaches at the end to the hull.

My rod is short, and thick, and has a big nut in the end that goes thru a steel rod that is horizontal

My rod is maybe 25 inches long

[bubb2]

If feel better knowing I have a longer rod than Alex. That is the part I thought that offend you!!!

[tomaz_423]

Alex, I do not want to compare Beneteau with your boat (Fiat to Ferrari), but the rod attachment on my B. 423 looks very similar.
There just 2 stringers and not 3, but the vertical rod is attached to the horizontal rod and the horizontal rod is webbed into some sort of stringers.
Here is a cut-paste from a Beneteau 423 review:
"Finot and Beneteau, separately and together, have engineered a great many hulls. While it’s topical, and appropriate, to boast that a boat meets European Union requirements, the best codicil to that is Beneteau USA president Wayne Burdick’s statement to me that Beneteaus have sailed many millions of miles without a hull failure.

That he can make such a claim is a credit to the way the company handles potential conflicts between the need to engineer the boat’s components for their own sake and the need to engineer them for economy in manufacturing. Behind the saloon settee is the chainplate that ties the cap and aft-lower shrouds into the hull structure. A tie rod is attached to the underside of the deck fitting and, with a toggle, to a horizontal stainless-steel bar glassed into a web structure in the manner I first saw on high-tech one-off racing boats."

[hellosailor]

Looks like a simple rod tying into ribs (and the hull to which they are bonded) and nothing really new. Tying into a bulkhead that was affixed to the hull would simply be more economical--if the bulkhead was in the right location. If not, the bars and ribs make sense to replace a bulkhead.

My only question would be if anyone tried to measure the load in the three ribs, to see if it was equal. If there's no way to equalize it across all three--I'd expect the spreader rod to worry the hole in one rib more than the others, or the load to be applied unevenly. Don't know if that would be a real problem or an ignorable one, I don't have the tools or experience to figure that beyond a doubt. Did your designer consider that? three ribs trying to play "weakest link" versus just one rib?

[sailortjk1]

Originally Posted by bubb2

Ales, I don't want to offend you! But it looks very much like the Beneteau tie rod system.

I was thinking the same thing.

[bubb2]

Originally Posted by hellosailor

Looks like a simple rod tying into ribs (and the hull to which they are bonded) and nothing really new. Tying into a bulkhead that was affixed to the hull would simply be more economical--if the bulkhead was in the right location. If not, the bars and ribs make sense to replace a bulkhead.

My only question would be if anyone tried to measure the load in the three ribs, to see if it was equal. If there's no way to equalize it across all three--I'd expect the spreader rod to worry the hole in one rib more than the others, or the load to be applied unevenly. Don't know if that would be a real problem or an ignorable one, I don't have the tools or experience to figure that beyond a doubt. Did your designer consider that? three ribs trying to play "weakest link" versus just one rib?

I don't know all about the engineering stuff but it is strong. I had a 45 ft Sea Ray Took out my back stay and a shroud and the tie rod didn't move at all. The rig stayed up also.

[Giulietta]

That system was overcalculated, the difference between it and the rest is the loading starts at he keel box, or the boat's structre, and not the boat's sides, as in the Beneteau and similar designs.

The load is "under" the boat.

The 3 ribs are different sizes to compensate the load shares and surfaces of adhesion...