Rigging Wire/turnbuckle Sizes

[ribbony]

We have in hand two good quotes for rigging gear to do our 35' cruising yacht with (out of about 8 quotes in total). There are two paths we can pursue from here and some questions that we need to answer.

One path is to rig with the same size wires 5/16" all round, except that the inner forstay and upper shoruds are 1/4". yacht is a Masthead, dual inline spreaders, 12mt stick, 7ton boat, single backstay with no runners, 4 x lower shrouds.

The other option is to alter the sizes of the rig wires (& terminals) to strengthen &/or lighten the rig. Fine tuning the design in other words.

Does anyone have opinions as to what wires on a rig like ours take the most strain and what wires have the least in the various conditions of cruising offshore ???

We can at this stage alter the rig to make some wires stronger, some lighter or have beefier turnbuckles at the bottom. Currently the plan is to have Ronstan Sealoc turnbuckles 1/2 unf and 1/2" clevis pins for the 5/16" stays. The option is available to up size to 5/8"unf & 5/8" pins if we gain from this upsize (& expense).

Cheers

[MMNETSEA]

hi

Quick questions what make and model of cruising boat ? How much sail - main and genoa ? boom length ?

Final :- why do you want to change - modify etc ??

[ribbony]

Joe Adams 35' cutter 1983 vintage, multichine steel hull, cruising fin keel. Have not worked out sail area, yet. have not sailed the boat, just worked on it for 3 years, almost there.

The reason for asking is simply seeking the strongest rig for weight and cost. If a particular stay needs to be a bit bigger from other past experience, then now is the time to modify the rig. Once we install it this time we do not want to be thinking we should have made that stronger, etc.

Perhaps our confiruration is ideal, great, we would leave it as is.

[MMNETSEA]

Originally Posted by ribbony

Joe Adams 35' cutter 1983 vintage, multichine steel hull, cruising fin keel.

Might consider beefing up the back stay by adding a 'monkey's face' ie.. splitting the back stay like this on another Adams 35 sloop :-





Also the forestay - consider 3/8th

As the boat is cutter rigged, then the aft shroud that terminates on the mast nearest to the inner forestay teminal should be of equal diameter.

Richard

[ribbony]

Thanks Richard !

I have noticed those forked backstays on other vessels and wondered what they were for. Doe's it stiffen the backstay compared to one long single strand ?

Beefing up the forestay is a good idea, especially as the furler is on it and that makes that wire harder to see and maintain.

The aft shroud terminates at the lower spreader to the same tang as the foreward lower shroud, the inner forestay terminates at the upper spreader.

The caps and uppers terminate on to a bridle like the one in the photo you posted of the adams backstay. That bridle then has a single clevis pin to a chainplate. I am not sure of the function of this feature, especially as one wire is the cap and is 5/16 and the other is the upper 1/4".

Lets see if I can get a photo attached.

Cheers

Mick

[MMNETSEA]

Originally Posted by ribbony

I have noticed those forked backstays on other vessels and wondered what they were for. Does it stiffen the backstay compared to one long single strand ?

Hello Mick

The 'forked' backstay if taken up at least 2/3rds of the distance certainly improves support on either tack. Obviously might be difficult to retrofit because of stanchions etc - however being a steel boat much easier than doing on plastic.

The "Monkeys Face" is a triangular plate - say 1/4" (6.5mm) about 4"x4"x4" 304 SS with holes at each corner to take a forked terminal.

If considering a HF radio at some stage a vertical whip works very well on a steel boat (as opposed to using the back stay)

Richard