If your rigging is in good shape... I don't see a problem with it.

 

It's probably safer (if it were ever in doubt) on a fractional rig in a blow than with a masthead rig because:
- The forces acting on the mast will be lower down (not at the masthead).
- Fractional rig headsails tend to be smaller than their masthead counterparts.

--Cameron

 

Actually, on a fractional rig, it can be more dangerous, since the mast may not be supported at the point the forestay attaches to the mast. With a masthead rig, the backstay and forestay attach at roughly the same point on the mast and will oppose each other. As long as the rigging is in good shape, it really shouldn't matter much with either type of rig. The larger forces generated by a masthead rig's larger sail are offset by the fact that the fractional rig may lead to the mast pumping.

 

No Hartley18, you must be kidding, right?

When a forestay is several feet lower than the backstay, it is unsupported to an extent. Raising the main helps counter this, but the shrouds contribute little to fore/aft support.

In a stiff blow, flying only the jib could cause weird bends in the mast, or even snap it off like mid-sheeted boom in the fun stuff.

 

OK...so tell me why raising the mainsail gives support to this partially unsupported mast?

 

..and since I don't have a backstay, I'd love to know how I'm going to get "weird bends in the mast".

If it was a really big blow, I could understand the shrouds parting and the whole thing going overboard, but I don't understand how the mast can be unsupported with only a jib up.

--Cameron

 

No backstay??? That definitely changes things.

Why no backstay???

 

Shiva is a fractional with swept back spreaders and very stout rigging. She also has runners which support the headsail and a storm jib. We've seen no problem with sailing using only a head sail, but rarely do it. Sometimes for sailing 3/4 of a mile across the harbor to the fuel dock. Roll out, roll in. Simple.

More likely we sail with only the main if we use one sail and hoist it to motor to stabilize the boat. Getting the main up is more of an ordeal.. sail cover and manual hoisting... blah blah blah

jef
sv shiva

 

Considering that a storm jib can be used as the only sail under some conditions it would seem unlikely that a designer would draw something that fails just when it’s most needed. Under all the conditions that I can think of just now, before my second cup of coffee that is, a main is trying to push or pull the panels of a mast out of column and that is harder on a mast then just the compression from a headsail. This assumes that the headstay pull is balanced by a jumper, running backstays or upper termination point of the upper shroud at the headstay with swept spreaders. If a particular boat is poorly designed then it’s just poorly designed but offhand I can’t think of a boat where I would be concerned as long as I used the running backstay, if rigged for one, and had the rig tuned properly.
All the best,
Robert Gainer

 

We sail on jib only sometimes. Ours is a fractional rig with no backstay -- shroud chainplates are a foot aft of the tabernacle. But givent this boat is rigged for a 240 sqft spinnaker, I reckon it can handle a 70 sqft jib okay.

Sailing upwind is difficult with headsail only; and to come about, you really have to work up enuf speed to get your nose thru the wind. Once you do, it's easy -- just leave the jib backsheeted a few seconds and you'll fall off nicely. May cause lee helm, which can put more wind in your sail than you want. OTOH, jibing on headsail only is stress-free -- no boom crashing over. Just keep your lazy sheet taut so the jib doesn't wrap around the forestay.

We reached home last weekend in 20+ knots on jib only. Our harbor was almost DDW, and we feared 3' swells on our stern could lead to accidental jibes. So we left the mainsail in the cuddy & flew the jib. It kept the nose out of the waves and pointed downwind, held speeds down to manageable levels, reduced our rolling moment, and carried us 7 miles in just over an hour.

 

Sailing with a jib is the way we make our sail only landings.

 

In heavy winds/seas I've been known to only fly the Jib/Genoa or a piece there of..., my boat is a fractional rig and I've never had an issue. Now I would NEVER fly the chute with anything but a full main (never with a reef). Hope that helps. gh

 

We knew a jBoat that was dismasted returning offshore from Bermuda with a reefed main, no jib, in a 50 knot blow. Cause? Mast whip w/o a jib to balance the force. I would think that wind velocity should be considered.

 

Practical Sailor looked at this about 15 years ago. They were trying to understand why there had been an inordinate number of mast failures connected with boats sailing under jib/genoa alone. I don't believe there was any distinction made as to fractional/masthead rigged. As I recall, the only pattern they found was that the vast majority of boats that experienced mast failure while flying headsail alone had one common aspect to their rig geometry: Single, rather than double, lower shrouds.

 

That's interesting. Do you remember a year or anything else I can use to track that article down? A mast with a single lower is weaker then the same mast with a double. So if everything else was the same I would expect to see a greater number of mast failures in the single lower rig no mater what the working sails were. I wonder if the article has numbers for the number of failures when both sails were up compared to when the boat was just under a headsail. Do more spars fail under headsail alone then under main alone? Also do more people sail under just the headsail because roller furling is so easy? If a backstay breaks the rig would fail no mater what your choice of sail was so looking at the cause of failure might be worthwhile. Did they do that in the article?
All the best,
Robert Gainer

 

It's interesting to me because:

1. I would have thought that having the forstay and shrounds connected to the same point and the rig tightened up to suit the weather, with a hinged mast step you couldn't get any significant mast movement, certainly not flex - unless I've missed something.. which is possible, SD..

2. I've been told that the majority of mast failures with my rig set-up occur at the spreader/mast connection - not at the shroud/mast connection. This could(?) only come with side-ways flex which I would not have thought you'd get under jib alone.

--Cameron

 

It's interesting to me because:

1. I would have thought that having the forstay and shrounds connected to the same point and the rig tightened up to suit the weather, with a hinged mast step you couldn't get any significant mast movement, certainly not flex - unless I've missed something.. which is possible, SD..

Last I checked, any time you put a mast under a heavy load, the shrouds will stretch a bit..and the mast will flex. On a small boat, the loads and the resulting flexing isn't going to be enough to fatigue the mast... but where the line between fatiguing the mast and not fatiguing the mast exactly is, is going to be pure guesswork. Also, how well engineered the chainplates and how well maintained they are will also effect the movement of the mast.

2. I've been told that the majority of mast failures with my rig set-up occur at the spreader/mast connection - not at the shroud/mast connection. This could(?) only come with side-ways flex which I would not have thought you'd get under jib alone.

--Cameron

Again... if the mast flexes enough, the spreaders may move enough to fatigue the base connection point. If that happens, the spreaders will detach from the mast and then fail completely.

 

thanks all, didn't know I'd spark such a discussion. I'll give it a try in a light breeze on my cal, which does have running backstays, though I don't play around with them much.

 

Robert,

The article probably came out in the early-mid-90's, which is when I subscribed to PS for a number of years. I'm sorry I can't be more specific than that -- having it in hand would be far more useful to this conversation than my vague memory.

But you're right, by that time roller furlers had become almost ubiquitous, so more folks were often opting to sail under jib alone for simplicity -- and apparently an inordinate number of mast failures had been observed with this sail configuration.

We're taxing my memory here, but as I recall, they looked at a lot of different aspects of rig geometry and sail combination when they were trying to find a common denominator, which as I previously noted turned out to be rigs that had only single lower shrouds. I also recall that the failures experienced were in the mast section, rather than in any of the shrouds or stays. That is to say, the mast snapped without any precipitating failure of the shrouds and stays. But these mast failures were occurring under jib alone -- there was no similar pattern under other sail combinations. I don't think they did any comprehensive analysis or comparison of other types of rig failures under other circumstances in that particular article.

One circumstance you mentioned was backstay failures, and I would just add it is my experience that backstay failures are not always as catastrophic as upper shroud or head/forestay failures, provided the mainsail is up. If the main is up some of the load borne by the backstay can be carried through the leech of the sail and then to the deck via the boom and mainsheet system. As you well know, many racing rigs sail with their backstays completely or very nearly slack in light air. Some of that load is absorbed by rig geometry (swept back spreaders and shrouds), but the sail and sheet are a factor as well. [I'm not saying backstay failures are inconsequential, only that they can sometimes be managed with quick action (turning upwind, getting the jib down, and leaving the main up sheated tight until halyards are led aft).]

In the PS article, they concluded that this load-bearing aspect of the mainsail and sheet somehow offset the rig stresses that occurred under jib alone on boats with single lower shrouds. Unfortunately, I do not remember why, and I am not qualified to speculate.

 

Thanks John,
My choice of backstay was just random and not meant to infer that a failure there was any better or worse then any where else. We have back issues in our library and I am going to see if I can find the article. It sounds like it would be interesting.
All the best,
Robert Gainer

 

Robert,

Great! I hope you can locate the article and clarify anything I may have misrepresented here. I would target the time period from 1992-1998 or so, but no later than Y2K. Sorry that's such a wide swath, but if it's any help I think this was the "cover story."

 

I'd think it would depend primarily on the rig. I'm rigged with forestay's, babystays, side shrouds, check stays and a adjustable backstay on a double spreader rig, with 320 sq ft of high roach main, and 340sq ft of roller jib and a 400+ ft screacher. I'd guess a 7/8 fractional rig.

The designer of my boat (Gemini 105mc) specifically states that if sailing with just one sail, use the main. Having said that, I roll out the screacher when I'm single handing because I'm lazy - but only if the wind is below 10knts.
I've noticed that Jib only in a puff generates a touch lee helm, not a good thing but manageable so far.
ChucklesR
Honor is a Verb, take action.

 

I guess my forestay, staysail stay, four uppers, four lowers and two backstays (one to each aft quarter) is perhaps overkill?

 

Nah, not at all. In fact, I'm surprised you risk sailing without a back-up headstay. You might also consider adding some running backstays, check stays, and jumper stays, just in case. Even if you don't have a sprit, go ahead and make up some whisker stays, and a bobstay, because you never know. And since you're hiring a rigger anyway, I would strongly advise that you add keel shrouds (from the chainplates down to the keel tip) to help support it when heeling, as well as a "rudder stay" from the end of the keel to the skeg. If you don't have a skeg (heaven help you), you could add a pivoting toggle at the base of your spade rudder. If this is a full keel boat, then you'll need a boomkin off the stern and the rudder stay can be led down from there (this is technically known as a boomkinrudderbackstay, or colloquially "bumpkinruster", but it's not a term you often hear nowadays). Don't forget lots of baggywrinkle all around for good, safe measure. Upsize everything because, well just because.

 

He does have a staysail stay as well as a forestay..

 

what for

You can try sailing jib only, the boat looks lame, and why would you. Try balancing the sails for the wind and it all is for the better. Yes you can. Esp. with the wind behind you. If you are shorthanded it is a good thing and if you add a little diesel it can be all balanced out. Why not sail, a sailboat?

 

I know this is an old post but the Practical Sailor article month/year was never posted. I expect that the reference is to Practical Sailor January 1997.

 

Grumpymx,

Hey, thanks for that follow-up! That article has been mentioned in a few places around here and no one to my knowledge had been able to find it yet (Robert Gainer, our good and knowledgeable friend who participated in this conversation, passed away not long after this thread got going.)

So, do you have a copy of the article handy, and if so, could you possibly summarize the findings? I'm sure my memory did not get it quite right.

 

Better yet, is that article available online or by back order?

Not that I find PS to be that great of a rag. Personal opinion obviously. I know may think of this mag as better than sliced bread. But the articles I see in the mag, for the cost, is rather short, altho some do have some good info. the more available/advertised rags have as good of info at times too.

I was in a WM looking for a GOB yesterday, and there were back issues still available up to a year ago on the shelf. BUT< this could be the store I was in too, most customers are probably ski boat oriented knowing the branch and area of town I was in. The three other stores I frequent at times sell out from my understanding.

marty

 

The Jan/1997 article date comes from my 93 year old uncle who has been a PS reader for years.
----------------------------------------------------------------------------------------------

Practical Sailor only has back articles from Jan 1998 to present online for download. I have emailed them to see it they can send a copy by regular mail......
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Answer from Practical Sailor"
Dear Sir,

We are sorry we only go back as far as 1998.

Jennifer

Jennifer Jimolka
Belvoir Media Group
Ph: 203 857 3144
Fx: 203 857 3158