Stays/Shrouds Too Short Fix

[Plymouth Sailor]

Dear Sailors,

Launched my friends boat with him yesterday and witnessed a surprising structural phenomenon.
The shrouds and stays were too short and nothing had changed since hauling the boat out last year. The average person would have no idea what to do but the pros kicked it up. They raised the vessel off her keel and bingo, the stays magically lengthened. They have seen this before where the keel pushes up the mast causing the rigging deficit!

 

[dlochner]

Interesting. What kind of boat? It is not unusual for boats to change shape while on the hard, however, having the keel push up sufficiently far to make the shrouds too short seems excessive. Either that are the shrouds are too short to begin with.

 

[Scott T-Bird]

Or the hull is too flexible? I'm not sure I understand why they had to pick up the boat. Why not just loosen the toggles? The toggles had to be loosened anyway to remove the shrouds, no? Are they at the extreme end of the range?

 

[Plymouth Sailor]

Rigging was at its adjustable limit, boat an O’Day 1988 302

 

[jviss]

loosen the toggles

You mean turnbuckles, not toggles, Scott. Toggles are used to make sure the shroud has a straight pull.

 

[Scott T-Bird]

You mean turnbuckles, not toggles, Scott. Toggles are used to make sure the shroud has a straight pull.

View attachment 206343

Yes!

 

[dlochner]

Rigging was at its adjustable limit, boat an O’Day 1988 302

The rigging is too short. And a boat that flexes that much in such a short time does not generate a lot of confidence in its build.

 

[Will Gilmore]

Did they have her on jacks? Maybe the problem was with the way the yard uses their jacks. If the hull sags around the keel, what is letting it do that? There should be jacks under the bow and stern, as well as along the chines. While the jacks' primary job is to keep the boat from falling over, the bow and stern jacks help keep the boat from settling around her keel.

-Will

 

[Plymouth Sailor]

Did they have her on jacks? Maybe the problem was with the way the yard uses their jacks. If the hull sags around the keel, what is letting it do that? There should be jacks under the bow and stern, as well as along the chines. While the jacks' primary job is to keep the boat from falling over, the bow and stern jacks help keep the boat from settling around her keel.

-Will

From my experience, the boat stands do support the boat from falling over but the keel supports most of the weight. I personally try to balance both. None of my boats have had that problem.

 

[Sandy Stone]

I have seen more than one hull dished in due to over-enthusistic application of the jackstands. AFAIK the boats regained their shape on being relaunched.

 

[BarryL]

Hi,

So I assume the boat was on land when the rig was set? That seems strange to me. I've always seen the rig set while the boat was in the water and floating.

I'm not surprised that the boat, when on the hard, had a different hull / deck / rig alignment than when floating. When in the water the keel is pulling down. When on the land the keel is pushing up.

Barry

 

[Scott T-Bird]

Hi,

So I assume the boat was on land when the rig was set? That seems strange to me. I've always seen the rig set while the boat was in the water and floating.

I suppose that depends on the yard, their equipment and their practices and perhaps the length of the mast. My masts have always been taken down and raised while the boat is on stands.

 

[Scott T-Bird]

Did they have her on jacks? Maybe the problem was with the way the yard uses their jacks. If the hull sags around the keel, what is letting it do that? There should be jacks under the bow and stern, as well as along the chines. While the jacks' primary job is to keep the boat from falling over, the bow and stern jacks help keep the boat from settling around her keel.

-Will

That's a good point ... if the deck sagged around the keel over the winter, that indicates the jack stands weren't sufficiently supportive.

 

[jssailem]

masts have always been taken down and raised while the boat is on stands.

when on the hard, had a different hull / deck / rig alignment than when floating

These are interesting observations.

I suggest that the decision of mast up or down when on the hard is made regarding ease of process or economics. Boat compromise.
My wonder which is best for boat hull longevity and the rigging.

• If the hull sags then is stretched I would think that would eventually contribute to fatigue somewhere.
• With the mast and rigging holding the boat from sagging what stress does that put on the rigging?
• With the rigging slack does the metal "spring back" to it's pre rigging application length?
• Is that a stress issue?

A conundrum....

 

[LloydB]

I was taught to unstring a bow when it was not being used to prevent permanent distortion of both the bow and the bowstring. To restring you have to over compress the bow in order to get the string back in place before releasing the bow to its proper tension. Kind of expect the same kind of results from taking the mast off of a sailboat whether it's in the water or on the hard. I seem to remember somebody saying avoid loose shrouds to prevent shock loads.

 

[dlochner]

I was taught to unstring a bow when it was not being used to prevent permanent distortion of both the bow and the bowstring. To restring you have to over compress the bow in order to get the string back in place before releasing the bow to its proper tension. Kind of expect the same kind of results from taking the mast off of a sailboat whether it's in the water or on the hard. I seem to remember somebody saying avoid loose shrouds to prevent shock loads.

All boats change shape when on the hard, some more than others. With that said, the stays should always be long enough to be attached in spite of the boat's shape. If they can't be attached, then they are too short or the hull has flexed too much. If the shrouds are too short, that's an easy fix, add a toggle or get longer shrouds. If the hull is flexing so much the shrouds don't fit, something is wrong with the hull.

 

[Project_Mayhem]

This makes sense if it's a keel stepped mast or the compression post is on the keel. When the boat is lifted by the hull the keel drops down a bit and so does the mast

My O'Day is just the opposite. It takes a 2-3 good sails to get the shrouds tightened up for the season.

 

[Plymouth Sailor]

All boats change shape when on the hard, some more than others. With that said, the stays should always be long enough to be attached in spite of the boat's shape. If they can't be attached, then they are too short or the hull has flexed too much. If the shrouds are too short, that's an easy fix, add a toggle or get longer shrouds. If the hull is flexing so much the shrouds don't fit, something is wrong with the hull.

Yeah, the distance was about 8”, a bit too far and unreasonable to add hardware that long. What I wonder is what happens if a boat with the same problem is stored for the season with the mast up? Must be a great deal of stress on the rig, so much so that damage could happen.

 

[Plymouth Sailor]

That's a good point ... if the deck sagged around the keel over the winter, that indicates the jack stands weren't sufficiently supportive.

Theoretically, boat stands are there only to prevent a vessel from falling over and the lion‘s share of the support is on the keel. I personally like sharing the weight between the keel and blocks and boat stands. I tighten the stands not to hold up the boat but support the hull firmly without significant weight on them.

 

[LloydB]

Woke up in the middle of the night last night and realized every sailboat does that when you disconnect the shrouds to take the mast down. With or without a forklift of course.