Tension in triatic stay

[Sea_Lark]

I replaced all the rigging on my 30 foot ketch over the winter and now need to re-tension the new stuff. I can find information on setting the tension for capstays, lowers, backstays, etc., but I have no idea about the required tension in a triatic. Can anyone help?

Come to think of it, what is the triatic for anyway? I presume it's for the mizzen, since the main already has backstays. But it connects to the mizzen at the hounds, and surely does the same job as the fore lowers on the mizzen.

Oh no, there's the jumper as well. What tension should that be? Is the triatic to balance the jumper at hounds level, so presumably has much less tension due to the angle difference?

I should have stuck with a sloop.....help!

 

[mickandbee]

or a gaff ketch

 

[guernseyman]

My triatic stay is cleated off on the mizzen after passing through a block above. It was clearly designed to be tensioned by hand, no more.

After using it pull the mizzen into alignment with the main mast, I cleat it off.

I believe it plays the part of a forestay for the mizzen. Forestays being somewhat over-valued, it may be a historical hangover from rigs that had derricks.

All my guesswork.

 

[chubby]

On my Barbary ketch, over enthusiatic sheeting of the mizen caused the mizen mast to push down and distort the aft cabin roof, despite having foreward lowers. I rigged a triatic rpoe stay which gives an upwards and forwards pull, problem solved, tensioned by hand and cleated off. The aft cabin doesn`t have a compression post: would get in the way, not really a design fault as it took 25+ years to come to light! Worth having the triatic stay but a rope one tensioned from the deck doesn`t make lowering the masts difficult compared to a wire one made off aloft.

 

[guernseyman]

Wire ones can be tensioned from below. Having it made off aloft sounds like an inflexible nightmare.

 

[William_H]

The triatic stay I think is the one between the mast tops. What is a jumper stay? Or is it the other way round.
Anyway I would think that the triatic is not a stay to be tensioned but rather it's length sets the distance between the mast tops. I am sure a ketch looks better with paralell masts which is what it does. The triatic is part of the train of wire that provides tension to the forestay. Which is necessary to stop forestay sag. The tension of the forestay being adjusted/ provided by the by cap shrouds of the main if their chain pllates are aft of abeam mast and by similar cap shrouds of the mizzen. Because you have 2 lots of stays providing forestay tension you will need to ensure reasonable load sharing.
ie too tight on the main mast caps pulling the mast top back and forestay tight will leave triatic and mizzen cap shrouds loose with no share of the load. Likewise too tight on the mizzen caps will pull the mast head aft via the triatic and leave main caps loose.
srry if I have got the picture wrong. Just draw a picture yourself from the side looking purely at the fore and aft pulls and loads. You will see how they relate. Side stays/ the aspect of the caps which pull sideways are adjusted to give a reasonable tension but most important to keep the masts straighht.
As for John Langham Browns aft cabin depressing I would be concerned. It is not just the mizzen jib tension that presses the mast down but also the side loads on the sail (heeling moment) translating through the side stays to downward mast pressure. It is possible that the cabin structure has deteriated over the years to allow more compression. You need better arch structure or a tempory support under the mizzen mast. You might want that mizzen to work really had in a storm one day.
good luck olewill

 

[Brian_Moffat]

Yup! It's to stop the upper masts from wobbling around. It continues the forces from the bows / forestay / triatic / backstay / stern - kind of keeps everything where it should be ( if it doesn't - at least they're all doing it in harmony).