Do I need Backstays on my Mizzen?

[don1]

Hi,
Can anyone help me with my question.

I have a 1973 Gulfstar 44 Ketch rigged MS,and am wondering whether I need backstays on my Mizzen, which has swept back spreaders.
The mizzen is 32 ft high, and the upper shrouds are 18" behind the centre of the mizzen mast.

I was wondering whether there is a formula for the angle of the spreaders to determine whether a backstay is needed?

If anyone can give me any help with this it would be much appreciated.

Thanks

[andert]

I have an Allied Seawind ketch with two sets of stays on the mizzen. One set is set slightly before the mast, and augments the forward tension of the spring stay that spans from the masthead of the main to the masthead of the mizzen. The second set is set abaft the mizzen, and provides sufficient tension aft to keep the mizzen from falling forward. Oddly, no spreaders on the mizzen. Looks a little weird, but the mast is short in relation to the beam, and apparently there is sufficient angle without spreaders. There is an adjustable stay, consisting of a four-part tackle attached to a wire stay that leads to the back fof the masthead fitting...this adjustable stay can be attached at the deck on either side by way of a snap shackle...it is designed to be used opposite a mizzen stays'l. Seems to me that backstays too far aft wouldn't allow for the mizzen boom to swing sufficiently forward during a run or broad reach.

[Brion Toss]

Hello,
Because mizzens are stuffed into the back of the boat, and because they must contend with deck structures, helm, and crew traffic, because of their disproportionate effect on the center of effort, because of the proximity of the main boom, and because they often are expected to take the load of a mizzen stays'l, mizzens present a challenge for staying. The springstay is one response. Swept spreaders are another. Also jumper stays, with or without springstay, forward-led intermediates, one or two sets of lowers, and so on. What your boat needs is utterly dependent on what variables your vessel's design presents.
Usually, aft-swept spreaders are paired with aft-led lowers and forward-led intermediates. With this configuration, one should not need a springstay. Nor runners. Yes, the aft lead does limit the travel of the mizzen boom, but helm balance typically limits the use of this sail to on the wind to a beam or moderately broad reach.
We don't have pictures of your rig; care to provide some? You might also want to look at the chapter on mizzens in the "Rigger's Apprentice."
Fair leads,
Brion Toss

[don1]

Hi Guys,
Thanks for your replies, and all the great information.
I am trying to attach 2 photos of my mizzen rig, but don't seem able to do this. There are both upper and lower shrouds, and as you can see from the photo the spreaders are swept back and the upper shroud where it attatches to the deck is 18" behind the mizzen mast centreline. The mizzen is 32 ft high.
So I suppose the question is do I need Backstays, Yes or No?

[andert]

As Brion's post implied, staying design is not a "yes or no" thing, it's a "depends" thing. I'm not a rigger, but I wouldn't give much credence to anyone who would tell you "yes" or "no" on adding backstays without seeing your boat, researching the original rigging plan, determining your intended use (i.e. day-sailing, coastal cruising, racing, offshore passagemaking), etc. Not much help, I know.

On the other hand, you could just add them and see what happens... if it were me, though, I'd probably look out on the web for any Gulfstar 44 owners that complain about their mizzens falling down before I'd spend a whole bunch of time, energy and money...

Todd Anderson
S/V Earendil