Mizzen running stay; staysail

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Paulus
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Mizzen running stay; staysail

Post by Paulus »

To not continue to hyjack bigd14' s Ericson 27 Project thread, (sorry bigd) I figured I would finish up over here - this pic shows the top of the mizzen

Image

The existing line is the topping lift; the second piece of bracket on the same side is where the running backstay was attached.

On the other (bottom) side is the triatic stay attachment and the block for the mizzen staysail. The mizzen halyard runs through the mast - the wire and sheeve are just visible. The sheeve runs over the bolt holding the brackets for the upper shrouds.

From what I've learned here so far - the upper shrouds need to be parallel to the mast as shown in this schematic:

Image

(They were were the lowers are drawn) - the lowers need to go on the middle chainplates and the Main split backstay on the most aft chainplates (they are angled just for that purpose.

When I fly the mizzen staysail

Image

I should attach the mizzen running backstay and not rely on any support from swept aft upper shrouds (as I did to-date).
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Rachel
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Re: Mizzen running stay; staysail

Post by Rachel »

Probably someone else more "riggery" understands this better, but could you possibly highlight which piece of rigging you are calling the "mizzen running backstay"?

The reason is, I can't picture how there could be one of those. Because.... the lower end seems like it would have to terminate in the water behind the boat (?) (So clearly I am missing something.)

I'm familiar with running backstays on the mainmast, as I've had/used those before.

Thanks,
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Re: Mizzen running stay; staysail

Post by Paulus »

The running backstay sits on the side of the boom - not behind it. As one tacks (or jibes), the running backstay needs to be released and re-set on the opposite side. At least that is the way I understand it to work.

I guess the re-setting can be done with the boom temporarily centered and the Mizzen sheet temporarily holding the mast...
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Rachel
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Re: Mizzen running stay; staysail

Post by Rachel »

Right but what I can't see on the drawing, or figure out in my head, is how the mizzen mast would have a running backstay. I'm familiar with mainmast running backstays, and right, they are not behind the boom -- if they were, they would be the regular backstay, and woudn't have to be "running," right? So maybe I was exaggerating slightly when I said they would have to terminate in the water, but they would surely be close to the very aft end of the boat(?).
Paulus wrote: I should attach the mizzen running backstay
Anyway, I can't see where on your diagram the mizzen running backstay is that you referred to. I can only see the mizzen shroud(s). So, I was just wondering if you could circle it or something so I could follow along. It's probably something I'm just not familiar with as I have never owned a ketch or yawl.

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Re: Mizzen running stay; staysail

Post by Quetzalsailor »

I'm a little surprised to see that the main's split backstay appears to rub on the mizzen's shrouds (if that's really what's happening in your picture). Make sure you have them passing as they were intended. I don't see the mizzen's running backstays shown on the drawing. I think you're right that they are to be used, alternately, just as any other pair of running backstays.

Rachel, that's why so many yawls have boomkins; they provide a place out over the water to anchor a permanent backstay. Yawl-rigged NE 38s and Bermuda 40s save the cost of the boomkin and simply extend the transom, the whole boat, out the necessary several feet. But a NE '35' or a Bermuda '37' just would not be so pretty!
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Rachel
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Re: Mizzen running stay; staysail

Post by Rachel »

Quetzalsailor wrote: Rachel, that's why so many yawls have boomkins; they provide a place out over the water to anchor a permanent backstay.
That I get. I just have never seen anyone working running backs on a mizzen, can't quite picture them in my head, and I also didn't see them in the drawing (as I understand them, anyway). But.... I've only sailed on a couple of Bermudian-rigged ketches (which didn't have them), and no yawls at all, so I'm asking as a novice.

I do see the two sets of shrouds on the mizzen mast, but presumably they are permanent?
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Re: Mizzen running stay; staysail

Post by Chris Campbell »

I may be wrong, but the impression I'm under regarding the mizzen running back is that it's a single stay which is deployed on one side or the other to counteract the mizzen staysail, when it's deployed (and is also always on one side or the other, and removed to tack or gybe). I doubt that it would be used any other time - the lowers angle toward the stern would be enough to keep the mizzen standing under normal circumstances - I think - with the triatic stay's raison d'etre being to keep the mizzen from falling off of the stern, not to act as a backstay to the main mast (since it already has one).

The split backstay hitting the mizzen's shrouds was evidently the result of the previous yard putting the lowers where the uppers should go and vice-versa - with the cap shrouds going to the chainplates that the lowers attach to in that picture, they wouldn't touch, and neither would the lowers (they'd be farther back and under the split backstay).

At least that's how it looks to me.
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Re: Mizzen running stay; staysail

Post by Tom Young »

My yawls running backstays connect with pelican hooks to bases on the stern. One per side.
949 sailplan jpeg 1000 px 2.jpg
The connections are welded to stern rail bases. You can flip off the pelican hooks downwind when letting the mizzen out fully. They're there simply to help support the loads of the staysail of course, and are rigged loosely for easy removal.

My guess is, one running back stay is missing on the Mariner ketch?
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Re: Mizzen running stay; staysail

Post by Figment »

I think Tom is onto something there. Particularly since flipping the runningback around the flying mizzen sail to re-set on the other side seems like a rather unseamanlike process.

I also think that the runningback, while it may STOW onto the boom, needs to be set to something on deck before being loaded. Otherwise it (or the topping lift) is redundant.
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Re: Mizzen running stay; staysail

Post by Paulus »

Chris Campbell wrote:I may be wrong, but the impression I'm under regarding the mizzen running back is that it's a single stay which is deployed on one side or the other to counteract the mizzen staysail, when it's deployed (and is also always on one side or the other, and removed to tack or gybe). I doubt that it would be used any other time - the lowers angle toward the stern would be enough to keep the mizzen standing under normal circumstances - I think - with the triatic stay's raison d'etre being to keep the mizzen from falling off of the stern, not to act as a backstay to the main mast (since it already has one).

The split backstay hitting the mizzen's shrouds was evidently the result of the previous yard putting the lowers where the uppers should go and vice-versa - with the cap shrouds going to the chainplates that the lowers attach to in that picture, they wouldn't touch, and neither would the lowers (they'd be farther back and under the split backstay).

At least that's how it looks to me.
Exactly the way it is set up.

The shrouds touch (very lightly, by the way) because the yard switched the chain plates. By doing so, however, they gave me the feeling that the running backstay was not really needed that much - except perhaps with the mizzen staysail flying - because of the swept back uppers.

Mind you – on my boat, which I single-hand 99% of the time – flying the mizzen staysail is synonymous with light air conditions.

A friend of mine has a Santana 2023 with a 35ft mast (tall rig), which does not have a back stay at all (nor a running back stay) - his shrouds and spreaders are swept aft - apparently enough to negate the need for a backstay.

As regards the single running backstay - I guess it is a pain to have to release, store and re-set it each time, but then, putting up the mizzen staysail is just as much of a pain because it too cannot be tacked or jibed.

Changing tacks with the mizzen flying - which would be the only reason for the running backstay - is a lot of work.

To tack or jibe:

1) drop the mizzen staysail (running backstay no longer needed)
2) disconnect and store the runner.
3) tack/jibe the mizzen
4) re-connect the runner
5) walk the tack of the mizzen staysail around to the other side of the mizzen boom
6) hoist the mizzen staysail

Better to pick a loooooong tack before deciding to use the mizzen staysail

Rachel - the running back stay is not shown on the schematic. Just picture another topping lift, but instead of it being connected to the end of the boom, it goes down to the (weather side of) the aft-most part of the deck.

Come to think of it, the topping lift COULD serve as the "second" running back stay, if it were removed from the boom and (also) connected to a small block and tackle, as is the designated running backstay.

Thanks for all your input - I am learning a lot here.
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Re: Mizzen running stay; staysail

Post by Rachel »

Thanks for the additional explanation - now I can visualize it.
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Re: Mizzen running stay; staysail

Post by boatsnh »

I'd take a look at the Mariner site to see what the mariner ketch rig was designed to carry & see if other Mariner folks use running backs.... The 3 ketches they designed don't seem to have drawings for running backstays .....

Often on a more modern ketch the uppers & lowers are sized to carry the load without running backstays at all. I have a set of builders plans for my Dickerson 36 ketch and they do not indicate a running backstay is called for & I've talked to a fair amount of folks with dickersons & i've never met one with running backstays. I don't think the pearson 365 uses them as a standard design feature either.

I find our mizzen staysail is a great light to moderate wind sail & really easy to set - I'll fly it in winds from 5-15 knots, but not much more. I suspect the load a staysail places on your mizzen in 10 knots of wind is no more than the mizzen would if sailing under jib/jigger in 20 knots of wind...

That said, my sense is a single running back would be a simple addition to use , since the staysail is not usually used if you plan to tack/gybe the boat a lot. Change tack - drop the sail & set the other 3 then raise the staysail again.....
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Re: Mizzen running stay; staysail

Post by Paulus »

boatsnh wrote: I suspect the load a staysail places on your mizzen in 10 knots of wind is no more than the mizzen would if sailing under jib/jigger in 20 knots of wind...
True, However, the mizzen sheet puts some of the load on the aft deck still and the sail/boom/sheet combo still provides for considerable balance to forward forces.

The Mizzen Staysail's effort - specifically the "forestay" effect provided by its luff - is almost 100% forward from the top of the mizzen.

Last season, with my swept aft uppers, there was more resistance to forward movement of the top of the mizzen than there will be if I "correct" the upper and lower set-up, to have the uppers parallel to the mast and the lowers connected aft.

While I know that this would be the correct setup - by design - I am not convinced yet that it is the better set-up considering there is no mizzen back-stay.
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Re: Mizzen running stay; staysail

Post by boatsnh »

Perhaps I'm missing something here...but I'll throw out a couple thoughts.

If I'm following this thread correctly it seems that your uppers & lowers on the mizzen are "switched" ant we are talkng about running backstays to support the loads of a staysail - a sail most ketch/yawl builders consider a fairly lightly loaded sail.

'My 2 cent's worth: I'd be more concerned about returning the rig to the designed specifications than making modifications to a rig not set up to designed specifications. Uppers & lowers to correct deck locations & chainplates. If it was "better" to run the uppers aft, they would have from the start. I can't imagine having rigging rubbing together is a good idea - In 45 years sailing I've never seen rigging "designed" to do so.....

Perhaps either prowl the Brion Toss' site for rigging advice, buy his rigger's hand book and do the math (there are also a couple of decent other rigging books out there - out of print) to calculate the loads on your uppers/lowers - or get a qualified rigger to "sort" this out for you. Ketch/yawl/sloop/marcon/gafferi....they all have their own interesting load characteristics on their rigs.

You might a few different thoughts/solutions to this little problem......be fun to see .
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Re: Mizzen running stay; staysail

Post by earlylight »

I agree wholeheartedly with boatsnh. I would return the uppers and lowers to their attachment points as originally designed,. Standing rigging should NEVER be allowed to cross in contact where the wires are then allowed to "saw" away at each other. Just my two cents.
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Paulus
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Re: Mizzen running stay; staysail

Post by Paulus »

boatsnh wrote:Perhaps I'm missing something here...but I'll throw out a couple thoughts.

If I'm following this thread correctly it seems that your uppers & lowers on the mizzen are "switched" ant we are talkng about running backstays to support the loads of a staysail - a sail most ketch/yawl builders consider a fairly lightly loaded sail.

'My 2 cent's worth: I'd be more concerned about returning the rig to the designed specifications than making modifications to a rig not set up to designed specifications. Uppers & lowers to correct deck locations & chainplates. If it was "better" to run the uppers aft, they would have from the start. I can't imagine having rigging rubbing together is a good idea - In 45 years sailing I've never seen rigging "designed" to do so.....

Perhaps either prowl the Brion Toss' site for rigging advice, buy his rigger's hand book and do the math (there are also a couple of decent other rigging books out there - out of print) to calculate the loads on your uppers/lowers - or get a qualified rigger to "sort" this out for you. Ketch/yawl/sloop/marcon/gafferi....they all have their own interesting load characteristics on their rigs.

You might a few different thoughts/solutions to this little problem......be fun to see .
If you knew me, you would know I will take this as far as I can before satisfying myself of the best possible setup.

I do appreciate your input - you make a lot of sense - especially about touching rigging not being a good idea - ever. Thanks for taking the time to put down your thoughts.
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