Redundant Standing Rigging

[seandepagnier]

I like the idea that if any stay, turnbuckle, or chainplate fails, the mast would stay even with sails up. This might not be entirely possible, but there are ways to increase the odds. I currently have a very standard rig of 1 forestay, 1 backstay, 2 uppers and 4 lowers. I have the following ideas for improvement:

1. Install U bolt behind forward chainplate. This must be well reinforced to the hull, and would allow the bottom of sails to attach here. This way if the chainplate fails (from ramming something maybe) it would have a backup. If the forestay or turnbuckle fails the halyard is backup (already the case). Is there a better solution to this?

2. Install two backstays. I have read about this a bit.. the basic disadvantages are, extra windage, weight, and cost as well as being harder to tune the rig. The advantage is redundancy since if one fails, the mast likely stays up (although might be loose). Are there any other real disadvantages? Anyone have a rig like this and tune it? Should the stays be placed as wide as possible, or would it be best to space them close so when one breaks you don't loose too much tension?


As for the shrouds.. loosing a lower should be ok, but the uppers are not redundant.. any way to improve this?

[maxingout]

Before I started my circumnavigation, I put up running backstays to back up the cap shrouds. That way if I lost the shrouds, the mast would survive.

During the circumnavigation (which took eleven years) I had to replace every piece of rigging at least once except for the cap shrouds. I don't know if the running backstays took the strain off the shrouds, or if it was coincidence that the shrouds were the only rigging that suvived the entire trip.

Regardless, I feel better crossing the Pacific or Indian Ocean with running backstays to push the odds in my favor.

[mrcarson]

My Favourites are a Cutter rig. 32 ft and 42 ft. Both steel with external S/S Chainplates all round.
32ft Pugh.
Dual 8mm Backstays. Wire Boom Topping Lift with 6 turn Mainsheet blocks. Spare Main halyard with a 3mm Kevlar line up mast. Mainsail Shackle at masthead.
Furler Genny 10mm forestay 8mm Shrouds with 9mm lowers to hold it up. Inner hank on Staysail. Storm Jib. Spare Forehalyard for 150 Drifter.
Boden 42ft same just heavier wire to suit extra loading.
Both Steel Heavy vessels with lots of laod bearing and strength. Don't bounce so much as plastic,aluminium etc. 2 suits sails. 3 month stores. and plenty of spares.
Desal and old truck tyre water evaporator. lots of fishing lures.
Time does not matter. just parts and stores to keep me going.
NO crew. NO responsibilities for others.
1 x 8 1/4 ton Steel Coffin at sea.
Plastic.(grp), Aluminium boats go faster. some. they ALL bounce all over the water. Steelies just go through. Much more comfort.
Sharks won't get my flesh. Chuckle.
29hp Yanmar 3 pot. had dual front alt sheaves. Which i could slip a drive belt onto driving a 1 1/2 in Bronze (old as me) H/D Water pump to empty bilges along with a large 3000 electric and 1in forrard bilge pumps. Single salt water intake in C/Cockpit drain, Portside. for ALL internal salt water intakes. Alternately a 75A Alternator to take down the Danfoss plates/freezer if it gets a bit warm.
Modified hull.Stern/transom. Wider. Flatter longer W/Line.
Kite. Drifter. 1 reef. She's logged 8+ flat water for 1+ days, her best record. Adelaide to Strahan back in mid '90's. But travelling light NOT loaded
20ish knots breeze,OFF the breeze. She often gave me around the 7 knots on log and GPS. (I reference to my Walker log and Sextant for distance logged. With GPS over the ground. It's Different to distance travelled over the water surface and speed).
Usually around 5.5 to 6.5 with any sort of breezeand a clean bottom.
Some boats are surprisingly slippy in some breezes.

[hpeer]

33’er, steel cutter. Fore stay, inner stay, backstay. I can not name all the stays but a single spreader rig so 3 on each side plus permanently installed runners. So that is 11 stays. It has one spare forestay halyard.

44’er, steel cutter. Fore stay, inner stay, 2 backstays. Double spreader rig, 4 stays on each side plus detachable runners. That is 12 stays plus the runners which could be moved as needed in case a stay was lost. It has 2 spare forestay halyards.


There is a LOT of redundancy in both boats. The rigs are not likely to come down easily. But still possible.

I think I would worry a lot about some B&R style rigs. It seems any one broken wire could bring the rig down.

Then again I have a deck stepped mast, I suppose that a keel stepped mast has some advantage in this regard.

[mrcarson]

When you look at a lot of todays modern "Offshore?????" Yachts.
I wouldn't go more than half a day sail offshore.
They light.Skinny. No reserves in them at all. Nothing I'd go out in.
I've been out for weeks in North Sea. and 2 x Atlantic Trawler runs in my younger life.
So I've seen some REAL Bumpy water.. 100+ft steel trawlers. we used to disappear down in the troughs. The winter Cod season was ferocious weather. We had cod in those days.
in the '50s, Timber North Sea boats. 55 to 70ft. we used to average one trawler a yr didn't make landfall some yrs. 100ft Steelies weren't so bad. (N.East England)
And people take these lightweight plastic buckets out there?. Sorry. NOT this little black duck. You have NO idea what real rough seas are. Your little toys would 98% shatter.

[Benz]

You'd be better off going up a size in each shroud than trying to double them. Same with turnbuckles, which if you make sure are bronze rather than SS, you'll never have to worry about. As for chainplates and attachments: if you go oversize with Titanium, you won't take the same weight hit as with SS, and you'll never worry about THOSE again.
But if you believe your rig was well-designed, and everything is new or well-cared-for, why worry about breakage? There's usually a healthy margin built in by prudent designers--if you don't trust them, the alternative is to become an engineer yourself, or else to festoon the mast with a jungle of extra line.
I tend to overbuild from the get-go, and not even bust a sweat later, but I don't build light, go-fast boats either.

[hpeer]

And yet insurance is the same for the very lightly built glass boat with a B&R rig, bolt on keel and spade rudder as for the heavily built, traditional rig, full or encapsulated keel, and well hung/protected rudder.

[tkeithlu]

QUOTE: "And yet insurance is the same for the very lightly built glass boat with a B&R rig, bolt on keel and spade rudder as for the heavily built, traditional rig, full or encapsulated keel, and well hung/protected rudder."

That doesn't surprise me. The actual loss figures may be quite similar, if very few claims are based on demasting or accidents that take out the rudder or keel and not the rest of the hull. Not many people take their plastic toys out in a North Atlantic winter storm. They're sinking them at the dock at a marina in Florida.

[thinwater]

Originally Posted by Benz

You'd be better off going up a size in each shroud than trying to double them. Same with turnbuckles, which if you make sure are bronze rather than SS, you'll never have to worry about. As for chainplates and attachments: if you go oversize with Titanium, you won't take the same weight hit as with SS, and you'll never worry about THOSE again.
But if you believe your rig was well-designed, and everything is new or well-cared-for, why worry about breakage? There's usually a healthy margin built in by prudent designers--if you don't trust them, the alternative is to become an engineer yourself, or else to festoon the mast with a jungle of extra line.
I tend to overbuild from the get-go, and not even bust a sweat later, but I don't build light, go-fast boats either.

^^ This. Go up a size. You'll add more strength with less complexity, windage, and cost.


Example. There are both single and double rope systems for rock climbing (2x7mm vs 10mm). Although a double rope system is stronger and theoretically more resistant to certain failures (cutting) and has lower impact force (less likely to pull anchors out), very few use it because it is more complex to keep both ropes "working."

[hpeer]

Originally Posted by tkeithlu

QUOTE: "And yet insurance is the same for the very lightly built glass boat with a B&R rig, bolt on keel and spade rudder as for the heavily built, traditional rig, full or encapsulated keel, and well hung/protected rudder."

That doesn't surprise me. The actual loss figures may be quite similar, if very few claims are based on demasting or accidents that take out the rudder or keel and not the rest of the hull. Not many people take their plastic toys out in a North Atlantic winter storm. They're sinking them at the dock at a marina in Florida.

Mark,

That may well be correct. And yet my insurance company just notified me that I MUST change all rigging at 15 years in order to obtain liability insurance. Are people loosing their rigs at the dock? Then again, looking at the Nanny Caye yard after the last hurricane maybe a lot? But were those failures due to design or age?

And how many encapsulated keels (or steel in my case) are making claims due to grounding damage as opposed to fin keel/spade rudders. I know I am being a bit of a broken record on this. But perhaps if insurance companies would use some discretion building practices would improve.

[Benz]

Originally Posted by thinwater

^^ This. Go up a size. You'll add more strength with less complexity, windage, and cost.


Example. There are both single and double rope systems for rock climbing (2x7mm vs 10mm). Although a double rope system is stronger and theoretically more resistant to certain failures (cutting) and has lower impact force (less likely to pull anchors out), very few use it because it is more complex to keep both ropes "working."

Also, very few climbers deal with windage.

[hpeer]

Is it true that certain catamaran rig designs are such that the rig will come down before the boat flips?

[hpeer]

Sean,

To answer you initial questions more directly, or at least attempt to….

It strikes me there are really 2 scenarios in play.

First what to do about the initial break, what happens in that first instance?
Second how to rig some form of repair at sea.

IMHO the first is the more serious and difficult problem.

My understanding is that the primary cause of failure is the turnbuckle or the wire immediately adjacent to the turnbuckle, chain plate failures are less common. There is the initial “pop” and a sudden shock load to the rig. It is hard for me to imagine and connection that significantly alleviates this initial shock load. You would need to have a second connection, a Y to the shroud and it would need to have some pre-tension in order to do much good. Such a system would be costly, difficult, complex, and probably add as much danger as it removes. The real answer is to not have the failure in the first place.

If you do have a failure and survive the initial shock load then various measures can be applied. In doing line construction work they have “wire grips” that close on the wire with a lever, the harder you pull the more they grip. It would be a simple matter to slip a grip onto the broken shroud and then run a block and tackle to the grip handle. Far from elegant but it wojld likely get you home.

If you had Stay Lock type fittings then you could reattach the turnbuckle above the break and use a chainplate extender to bridge the gap.

The trick is to survive the initial shock loading until you can jury rig something.

As hou know I am no expert on this but the question has crossed my mind. I simply offer you my best ideas to date.

[mrcarson]

Offshore cruising. Oversized rigging.Chainplates to hull and proper reinforcing internal to hull is preferable. You should not be out in real seas with one of these lightweight worrying about weight, floating plastic boxes.
My 2 last boats. Steel 32 ft 8+ ton/42ft/17ton. Offshore tanks. and not slow with design.
Both built that they could. with full loading. Be lifted on chainplates.
Me a crane operator/Mechanic. Weighed them on boom scales early on.
Carry chain shorteners.Claws. Cable clamps/joiners.
Go to a rope Chain suppliers in any big town/city. They carry most of what we need at lower pricing than marine dealers.
Shroud ends usuall "splay" if letting go under stress.(fan out) Hard to get togeter and insert into clawFit a U Bolt over csble near splay. spiral it down to end. Tighten nuts. Easier to insert then.
OR. Several cable clamps. lay a short piece of sized shroud wire alongside broken ends. Will hold of not stressed too much. Sometimes possible when shroud still in place. (Weather permitting.
BUT Plastic boats. Have a good pr of cable/bolt cutters by steps.
To cut away rig and trail behind you. BEFORE it drives holes in hull.
A floating boat is better choice than a sinking. Holy hull WITH it's rig.
Going down together.
AL offshore sailors should do at least one trip on a North Sea /Bering sea trawler.
Just to see what the seas. From flat. CAN. Quickly. really get to.
Then look at their boats.
I was a deckie for 4+ seasons in mid '50's on Open deck Not a modern Enclosed deck N/Sea Trawler. 100ft Steel and felt like a dinghy. We were under it more than on it believe me. Went in Army to get me a Trade (Mechanic)
Land people have absolutely NOOOO idea what the sea can do to itself in a very short period of time when it blows up. I'm 80 and spent a lot of my life at sea.
Still **** myself when that quiet/still time comes. Just b4 the real blows. and coastal CAN be worse than offshore where is can spread itself out a bit.
But we always go back again, don't we hey. Dumb as.

[seandepagnier]

Originally Posted by hpeer

Sean,

To answer you initial questions more directly, or at least attempt to….

I am quite surprised you are answering my question from 12 years ago.

Anyway... I think the real issue is stress corrosion in stainless. With 316 is less of an issue but still there. I am therefore looking for redundancy for anything relying on 316, but for the outer shrouds, I plan to attach them by wrapping dyneema loops under the akas rather than chainplates.

The backstay I plan to split with a Y, and if either leg attaches to something stainless... maybe a bad idea because if one chainplate fails, the other may immediately after, but then again sharing the load will cut the stress in half meaning stress corrosion is much less likely to begin with.