Rigging Question.

[DJE]

Is there any reason for having double toggles at the bottom of my backstay? It seems to me that a single toggle would give full articulation because it has two pins at right angles to each other. At the moment the bottle screw is closed and I want to get a bit more backstay tension on. There is enough adjustment in the screw to allow me to take the bottom toggle out and connect the top one direct to the chain plate.

 

[alahol2]

All my rigging only has the one toggle, a strap similar to yours. The rigger who supplied it didn't see the need for anything more.

 

[lw395]

Maybe it's there to give an option to have a lot less rake?
The only time I've heard double toggles suggested as a good idea is in a forestay that's going to go really slack when you let off the backstay down wind.
Then the toggle allows the stay to stay straightish and just flop to the side.

But sometimes extra toggles happen because it's easier to cut the stay an inch too short and add a toggle than to shorten one that's an inch too long.
E.g. if it's not exactly known what rake you need.

 

[neil_s]

In theory, one toggle is enough, but I suspect you might find that your Gibb bottle screw toggle wont fit on your chainplate.

 

[pvb]

In theory, one toggle is enough, but I suspect you might find that your Gibb bottle screw toggle wont fit on your chainplate.

That was my suspicion; it looks too big.

 

[oldmanofthehills]

My rigger said is was the custom once and if I'd shown him my boat not sent him my old stay he would have eliminated the second toggle, but as i hadn't my stay was too short so I needed to keep it and no harm done

 

[PetiteFleur]

Interesting - I have to replace my standing rigging this winter at the request of my insurance company and all my shrouds have extra toggles as the photo(apart from the forestay which is an integral Rotostay turnbuckle). one cap shroud even has two! And I assumed this was normal but after speaking to local riggers said the toggles were not necessary and just use the toggled turnbuckles which is the norm nowadays.

 

[DJE]

Thanks for all the replies.
I'll give it a go and if the corner of the toggle fouls the chain plate I might have to round it off a bit with the bench grinder. But from the side it looks like there should be enough room.
Interestingly the forestay has one toggle and the shrouds have none.

 

[NPMR]

Not sure if it's the same thing, but we lost a mast stay in a big blow and nearly the mast.

When investigated, the rigger advised that there were no extra toggles anywhere, so when flexing under strain, the twisting and working loads were not allowed for in the set up. So the bottle screw became brittle and snapped.
The extra toggles allowed sideways as well as lateral movement.

We had the whole set up changed to include toggles on the end of every stay.

 

[mjcoon]

Thanks for all the replies.
I'll give it a go and if the corner of the toggle fouls the chain plate I might have to round it off a bit with the bench grinder. But from the side it looks like there should be enough room.

If the toggle allows a lot of clearance sideways to the chain plate, will you pad it with washers to keep it central? That way the stress on the pin will be more evenly spread...

Mike.

 

[DJE]

All done!

 

[neil_s]

Well done! Like the spacing washers too. I guess these toggles are a throwback to when bottle screws didn't come with them built in. I certainly have quite a collection in my scrap box. They can come in handy sometimes, though. I decided a few years ago that I needed a bit more mast rake - hey presto! two toggles under the furling drum and the lee helm was gone and the genny didn't foul the guard rails any more!

 

[peter gibbs]

If you remove a section from this arrangement how will you connect the bottle screw to the deck plate? It looks as though it was all put in to answer this question: if you want to foreshorten the stay, you will need a different connector.

PWG

 

[Tomahawk]

I don't like the look of that. The pin is now subject to bending as well as shear. In shear it is pretty strong. But once it begins to bend?
Do not be surprised if the pin through the chainplate bends and refuses to come out.

The lods of those induced by well controlled gybe are pretty huge... Then think about an accidental slam!

 

[DJE]

If you remove a section from this arrangement how will you connect the bottle screw to the deck plate? It looks as though it was all put in to answer this question: if you want to foreshorten the stay, you will need a different connector.

PWG

Post #11 is the after picture. The before picture is in post #1.

 

[DJE]

I don't like the look of that. The pin is now subject to bending as well as shear. In shear it is pretty strong. But once it begins to bend?
Do not be surprised if the pin through the chainplate bends and refuses to come out.

The lods of those induced by well controlled gybe are pretty huge... Then think about an accidental slam!

Without the washers it was about the same as the original arrangement where the bending capacity of the pin was about the same as the break load of the wire. But the close-tolerance washers support the pin and reduce the bending moment. Shear capacity is about 150% of the breaking load of the wire. (I do structural steel and aluminium design for a living!)

It's a masthead rig on a boat with a low bow. The shock loads when a big wave breaks into the the genoa are the ones that worry me. But you're right - gybing in a blow can be pretty dramatic too.