Moving or Splitting Aft Stay

[goslin]

Can you split the aft stay part way down so it does not connect center line where you sit and get in and out of the water using the swim ladder?

[GordMay]

Yes.
The original single backstay from the masthead would terminate at a (triangular) tang plate some distance (±8 - 10' ?) off the transom deck, and two legs would then split off and run down to either side of the transom, forming an inverted “wye”.
Keep the split as low as possible, while still keeping backstay legs from obstructing flow of traffic through/over the transom.
Ensure that the (2) new chainplates are properly angled to provide a fair load path to the split plate.

For example:

[holmek]

If possible, check with the designer of your boat or a rigging specialist that the transom can take the load at the corners rather than in the middle.

[skipmac]

Originally Posted by GordMay

Yes.
The original single backstay from the masthead would terminate at a (triangular) tang plate some distance (±8 - 10' ?) off the transom deck, and two legs would then split off and run down to either side of the transom, forming an inverted “wye”.
Keep the split as low as possible, while still keeping backstay legs from obstructing flow of traffic through/over the transom.
Ensure that the (2) new chainplates are properly angled to provide a fair load path to the split plate.

For example:

Hi Gord,

Have the same idea for my boat also for easier access from the transom ladder and to add a backstay tensioner by squeezing the legs together with a pulley system.

So how come installing the plate as low as possible? I can guess to facilitate inspection of the plate and terminals where the three wires join but is there some structural reason?

Thanks
Skip

[Mark1977]

I had a PY 23 before setup that way, here's a pic of one to give you an idea.

[skipmac]

Originally Posted by Mark1977

I had a PY 23 before setup that way, here's a pic of one to give you an idea.

How did you like the backstay tensioner aspect of the design?

[Mark1977]

Originally Posted by skipmac

How did you like the backstay tensioner aspect of the design?

To be honest i never used the tensioner much. Once it was set i left it alone. Unless you are racing i think a set up without the tensioner would be fine.

[Target9000]

I doubt it is a concern on all boats, but on boats like ours (W32 - canoe stern), some people have done this and it was quite a big job involving far more than just rigging concerns. Most of the owners that completed this ended up needing to cut the boom off and also have sails re-cut to ensure proper clearance between the end of the boom/sail and the backstay. Like I said, I doubt this is a common problem but one I might bring up since the question was asked.

[GordMay]

Originally Posted by skipmac

... So how come installing the plate as low as possible? I can guess to facilitate inspection of the plate and terminals where the three wires join but is there some structural reason?

I was wrong! Put the tang plate as high as is reasonably practicable.

As the angle between the horizontal transom deck and the “Y” backstay rising to the triangle plate decreases, the resultant load on each leg increases. A 30 deg. load angle doubles the tension.

Accordingly, a higher split point would be structurally preferable* to a lower one.

* Notwithstanding a slightly higher weight aloft & etc (as you noted).

[Bash]

Originally Posted by GordMay

Keep the split as low as possible, while still keeping backstay legs from obstructing flow of traffic through/over the transom.

I've heard the opposite advice, that the split should be high. Simple physics would seem to argue in favor of a higher tang, although I suppose that splitting the backstay too high might make it difficult to isolate the backstay as an SSB antenna, if that's a consideration.

[EDIT] Oops, I see that GordMay later corrected this advice. When will I learn to read the whole thread before responding? Sorry, Gord.

[GordMay]

Originally Posted by Bash

I've heard the opposite advice, that the split should be high. Simple physics would seem to argue in favor of a higher tang ...
[EDIT] Oops, I see that GordMay later corrected this advice. When will I learn to read the whole thread before responding? Sorry, Gord.

No, you are correct, and the original fault was mine. Sorry for any confusion.

[Matt sachs]

Is it sound engineering to attach the tang plate to the top of the mizzen, effectively having two back stays?

[goslin]

I called a rigger and he said the same thing about being high up with the split, and the chain plates should be of proper strength. About $900 to have them do it. Worth it to me to have that room aft of the helm, and the swim ladder. I offered to install the chain plates too cut the cost, but for obvious reason they want to do it all, ya know, "they did it, no, he did stuff" Anyway thank you gentlemen for the input, it was all consistent and made sense.

[GordMay]

Originally Posted by Matt sachs

Is it sound engineering to attach the tang plate to the top of the mizzen, effectively having two back stays?

No.
Brion Toss (rigger extraordinaire) on “WHY DOUBLE BACKSTAYS ARE EVIL”
➥ Pieces of String Too Short to Save

[goslin]

I know these riggers are there to make money, but knowingly put the boat and capt. in harms way? Is this one guys opinion, or are there more? I see law suits out the a-- if this is a dangerous thing to do to a boat! Because this rigger I talked to acted like it was no big deal, and like he has done many times before.