[bolger] Re: mj knockdowns: summing up so far
In a message dated 3/7/2000 6:49:24 PM Eastern Standard Time,
ewhaile@...writes:
<< All the same, Steve, in light of things I wish you'd give us an actual
weight on that mast, including the boom, yard, and sail. ED HAILE
those sail ties - taking the mast off would be a royal pain :-( This was all
pretty nice clear dry lightweight spruce - much much lighter than fir - Steve
ewhaile@...writes:
<< All the same, Steve, in light of things I wish you'd give us an actual
weight on that mast, including the boom, yard, and sail. ED HAILE
>>Hi Ed - I understand - but I'm not sure I want to dismantle everything! All
those sail ties - taking the mast off would be a royal pain :-( This was all
pretty nice clear dry lightweight spruce - much much lighter than fir - Steve
All the same, Steve, in light of things I wish you'd give us an actual
weight on that mast, including the boom, yard, and sail. ED HAILE
weight on that mast, including the boom, yard, and sail. ED HAILE
>My mast is not all that heavy - I haven't weighed it - but it's built of______________________________________________________
>spruce not fir - I can carry it myself pretty easily. Obviously spruce
>floats! It wouldn't sink on it's own.
>
>I explained in another recent e-mail why I have solid ballast so I won't
>repeat all of that! :-) But it did not shift because it was inside the
>ballast tanks - and I took the lids off yesterday and removed it all to let
>things dry out. I know it weighed 500 lbs. because I weighed each bag as I
>put it in.
>
>clew to clew reefing - that's interesting - I haven't thought of that - I
>have a jiffy reefing line that in one pull pulls the mainsail down to it's
>first reefing point. Next time I raise the sail I'll have to experiment
>and
>see what that looks like. A double reefed sail is pretty small.
>
>I don't think the boom reaching the water and dipping in caused this.
>
>Hull windage -
>
>When she is beam ends in the water and the bottom is flat toward the wind -
>that's a big surface for the wind to push against. I can't even imagine
>what
>it would take to right against that kind of pressure. Once the bottom is
>perpendicular to the water and face to the wind - why not blow over if the
>wind is strong enough? In 9 feet of water it doesn't need to go very far
>before the mast hits the bottom and then being pushed by the wind the mast
>would just dig in.
>
>The rudder has worked perfectly - and under normal conditions I have a nice
>balance with a bit of weather helm - and there is no reason the outboard
>would be "fighting" that. The outboard was not running for very long - not
>long enough to have a chance to do very much - it was pretty much
>overpowered. I would like to go to five horses - but don't like the extra
>weight
>
>we took all the sails off but left the mast upright before righting the
>boat
>- there was no way to lower the mast. It did not take much to make her
>come
>up - a benefit of solid ballast perhaps.
>
>I don't think the boat is too unsafe in any conditions - I think that there
>was probably a combination of factors at work here. We had sailed for 1 1/2
>hours in this same wind - maybe even more wind because we were on a lake
>that
>was at least five mile across for the first 1 1/2 hours before any of this
>ever happened. This happened on the smaller more sheltered lake. We never
>even had a white knuckle moment - most of that sailing was a beam reach -
>the
>boat was steady and sailing flat. The McGreagor was rounding up - and
>reduced
>sail area twice - going from full sail to reefed main to reefed main
>without
>a jib - the pocket cat dropped sail completey and motored - we on the other
>hand - kept right on sailing - at the end of 6 miles we were at least a
>mile
>ahead of them - dry and comfortable. On the other hand - when we knocked
>down the mcgreagor was right along side of us - and they survived when we
>didn't.
>
>I don't know what else to add! Except maybe some more ballast??
>
>steve
>
>
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Hi Ed -
My mast is not all that heavy - I haven't weighed it - but it's built of
spruce not fir - I can carry it myself pretty easily. Obviously spruce
floats! It wouldn't sink on it's own.
I explained in another recent e-mail why I have solid ballast so I won't
repeat all of that! :-) But it did not shift because it was inside the
ballast tanks - and I took the lids off yesterday and removed it all to let
things dry out. I know it weighed 500 lbs. because I weighed each bag as I
put it in.
clew to clew reefing - that's interesting - I haven't thought of that - I
have a jiffy reefing line that in one pull pulls the mainsail down to it's
first reefing point. Next time I raise the sail I'll have to experiment and
see what that looks like. A double reefed sail is pretty small.
I don't think the boom reaching the water and dipping in caused this.
Hull windage -
When she is beam ends in the water and the bottom is flat toward the wind -
that's a big surface for the wind to push against. I can't even imagine what
it would take to right against that kind of pressure. Once the bottom is
perpendicular to the water and face to the wind - why not blow over if the
wind is strong enough? In 9 feet of water it doesn't need to go very far
before the mast hits the bottom and then being pushed by the wind the mast
would just dig in.
The rudder has worked perfectly - and under normal conditions I have a nice
balance with a bit of weather helm - and there is no reason the outboard
would be "fighting" that. The outboard was not running for very long - not
long enough to have a chance to do very much - it was pretty much
overpowered. I would like to go to five horses - but don't like the extra
weight
we took all the sails off but left the mast upright before righting the boat
- there was no way to lower the mast. It did not take much to make her come
up - a benefit of solid ballast perhaps.
I don't think the boat is too unsafe in any conditions - I think that there
was probably a combination of factors at work here. We had sailed for 1 1/2
hours in this same wind - maybe even more wind because we were on a lake that
was at least five mile across for the first 1 1/2 hours before any of this
ever happened. This happened on the smaller more sheltered lake. We never
even had a white knuckle moment - most of that sailing was a beam reach - the
boat was steady and sailing flat. The McGreagor was rounding up - and reduced
sail area twice - going from full sail to reefed main to reefed main without
a jib - the pocket cat dropped sail completey and motored - we on the other
hand - kept right on sailing - at the end of 6 miles we were at least a mile
ahead of them - dry and comfortable. On the other hand - when we knocked
down the mcgreagor was right along side of us - and they survived when we
didn't.
I don't know what else to add! Except maybe some more ballast??
steve
My mast is not all that heavy - I haven't weighed it - but it's built of
spruce not fir - I can carry it myself pretty easily. Obviously spruce
floats! It wouldn't sink on it's own.
I explained in another recent e-mail why I have solid ballast so I won't
repeat all of that! :-) But it did not shift because it was inside the
ballast tanks - and I took the lids off yesterday and removed it all to let
things dry out. I know it weighed 500 lbs. because I weighed each bag as I
put it in.
clew to clew reefing - that's interesting - I haven't thought of that - I
have a jiffy reefing line that in one pull pulls the mainsail down to it's
first reefing point. Next time I raise the sail I'll have to experiment and
see what that looks like. A double reefed sail is pretty small.
I don't think the boom reaching the water and dipping in caused this.
Hull windage -
When she is beam ends in the water and the bottom is flat toward the wind -
that's a big surface for the wind to push against. I can't even imagine what
it would take to right against that kind of pressure. Once the bottom is
perpendicular to the water and face to the wind - why not blow over if the
wind is strong enough? In 9 feet of water it doesn't need to go very far
before the mast hits the bottom and then being pushed by the wind the mast
would just dig in.
The rudder has worked perfectly - and under normal conditions I have a nice
balance with a bit of weather helm - and there is no reason the outboard
would be "fighting" that. The outboard was not running for very long - not
long enough to have a chance to do very much - it was pretty much
overpowered. I would like to go to five horses - but don't like the extra
weight
we took all the sails off but left the mast upright before righting the boat
- there was no way to lower the mast. It did not take much to make her come
up - a benefit of solid ballast perhaps.
I don't think the boat is too unsafe in any conditions - I think that there
was probably a combination of factors at work here. We had sailed for 1 1/2
hours in this same wind - maybe even more wind because we were on a lake that
was at least five mile across for the first 1 1/2 hours before any of this
ever happened. This happened on the smaller more sheltered lake. We never
even had a white knuckle moment - most of that sailing was a beam reach - the
boat was steady and sailing flat. The McGreagor was rounding up - and reduced
sail area twice - going from full sail to reefed main to reefed main without
a jib - the pocket cat dropped sail completey and motored - we on the other
hand - kept right on sailing - at the end of 6 miles we were at least a mile
ahead of them - dry and comfortable. On the other hand - when we knocked
down the mcgreagor was right along side of us - and they survived when we
didn't.
I don't know what else to add! Except maybe some more ballast??
steve
Dear Steve,
This calls for a cup of coffee. All those other boats knocked down too? It�s
a dangerous situation. This is the most serious discussion I�ve seen on the
group in my long career of four months. As of noon 3/7 I have decided to
recap your points & add a few notes & observations.
THERE WAS NOTHING INSIDE THE BOAT BUT 500 LBS OF SAND.
That�s an odd practice. Why didn�t you use water ballast & how exactly did
you know the sand weighed 500 lbs? Please assure us that none of it shifted.
MIZZEN LACES BROKE. PERHAPS THE SAIL WAS BAGGING. IT MADE IT HARD TO HEAD
UP.
If the mizzen was catching & bagging wind it should have aided heading up. I
suspect it was spilling. I know in that situation the MJ has lee helm and
wants to fall off, particularly if she is also slowing.
25 MPH WIND
Look, that is not a lot of wind. A boat that can�t use Force 6 is
unseaworthy. That�s a great sailing wind.
MAIN WAS UNCLEATED AND LUFFING.
I have been bothered by the MJ�s mainsail. Uncleated in those conditions she
is in danger of tripping over her boom when the clew hits the water. Bolger
warns of this. In addition, when she luffs down where you are looking at
her, her yard may not necessarily be blowing out aloft. If the mainsail is
not reefed but full, this problem could be exacerbated by the standard
placement of the halyard sheave low on the aft side of the mast. If you hang
your lug rig to starboard, for example, then on a port tack you develop
considerable twist in the halyard fall. Maybe too much twist if the fall is
very short.
The cure, I suggest, and which I have installed on my own MJ, is to raise
the sheave some (mine hangs within 12� of the mast peak), and to reef my
boat clew to clew instead of the usual Marconi system of tack to tack. That
shoots the boom forward each time you tuck one. Bolger recommends this
system for our boat, even though it is one or two motions extra.
HULL WINDAGE KNOCKED HER DOWN TOO EASILY.
All boats give you a feeling of surrender when they at last capsize after
heeling further and further. But hull windage? An MJ is high-sided, but
remember that her sides are aslant to deflect the wind with little for it to
grab when she heels. Nearly every other boat out there, including all your
roundbottom dinghies and clorox bottle types throw up much more beam when
they heel, and their shape tends far more to catch the wind in the
underbody. It�s a long way over before the MJ shows any underbody at all.
This is a common misconception about the factor of boat windage. Most people
assume a high sided boat has more windage than a low sided boat. Wrong.
Windage is a factor of beam, not freeboard, under the conditions you are
describing. Topside it is very much a factor of standing rigging.
WIND PRESSURE ON THE BOTTOM PUSHED HER DOWN UNTIL SHE FLOODED THROUGH THE
COMPANIONWAY AND DROVE THE MAST UNDER TO STICK FAST IN THE MUD (like a
Chinese pole anchor).
I am not sure when I read this whether the culprit was wind pressure or
gravity. It sounds like your mast sank on her own, too quickly at any rate.
It should take a lot more than a Force 6 breeze to push a buoyant mast and
semibuoyant sails under at such an angle that a 20� spar finds at 9� lake
bottom. And all this while fighting against the righting moment of 500 lbs
of sand bags. Something is very wrong here. A non-buoyant, too heavy mast
would explain an awful lot of your boat behavior.
TRIPPED OVER THE LEEBOARD.
Since it is impossible to go to windward without an extended board (under
any conditions), and it is impossible to raise a board when you think the
boat is going to capsize, there�s no point in discussing this as an option.
It�s about like saying you should furl the mainsail if the think the boat is
capsizing. Leeboards, centerboards, fixed keels, whatever, I don�t think
their shapes or positions have anything to do with your/our solution.
LEEBOARDS TOO WIDE FOR QUICK STEERING.
I disagree completely, comparisons with the Sea Pearl notwithstanding. Not
at all my experience.
2 HP HONDA OVERPOWERED.
That�s a small engine, all right, but have you explained that you have a
non-standard self-designed transom-hung rudder? It could be the little
engine was fighting that more than it was the wind. But again, no proper
sailboat needs an engine to avoid capsize.
SAIL DOUBLE-REEFED, YARD AND MAST (? don�t you mean boom?) SET LOW.
With mizzen set and probably bagging terribly at the same time the clew end
of the boom was hitting the water, it might be that we can explain this one.
WENT DOWN NICELY TO LIE FLAT WITH THE HATCH ABOVE WATER UNTIL WIND PRESSURE
MADE HER TURTLE.
Again, look at that mast as the culprit. Catamarans go turtle when their
masts fill up with water. Yours, whatever material, does not sound very
buoyant or very light.
WAVES SMALL.
Should not be a factor anyway.
WANT TO ADD FOAM.
The locations you suggest are all low. Foam needs to go high. The best
place, unfortunately, is the peak of the mast. Otherwise, under the cabin
top, maybe under the cockpit seats. But, Steve, your boat floated fine with
no foam at all and 500 lbs of negative ballast in sand.
TRAPPED AIR UNDER COCKPIT.
When the swamped boat is rolled upright, it stands to reason her mast weight
will push her down forward while her cockpit seats will provide plenty of
low buoyancy aft. The cabin top out of the water is more negative buoyancy
forward. It is unlikely if she lay on her side awhile she trapped any air
aft.
On the other hand, did you furl the sails or drop the mast?
�WHAT I�D REALLY LIKE IS ONE MORE FOOT OF BEAM�
Maybe so, but that�s a foot more windage and a foot more stability turtled.
WENT SLOWLY FROM 45 TO 90.
One more factor that makes me strongly suspect your ballast was working but
your mast weight was working harder.
GLAD MY DAUGHTER WASN�T IN THE CABIN.
This is where the discussion gets very serious & as an MJ owner I am pretty
upset about the implications. As she sits, your boat is too dangerous to put
out in any conditions. And maybe mine is too. That said, it sounds like
passengers, as you describe the situation, would have had ample time to
evacuate before the wind, as you said, pushed her down. On the other hand,
what if the hatch had been closed? It might have been difficult to open. Who
knows? And by the time it was opened, water might have been rushing in.
TO SUM UP, my computer (the one I carry on my shoulders) says your boat
displays every indication that you have a mast & sails made of solid lead or
maybe even plutonium. Check the label. But all Marthas seem to be too
sluggish in saving themselves, so it�s time to canvas the fleet & map out
some good ways to improve her snap in recovery.
Ed Haile
______________________________________________________
This calls for a cup of coffee. All those other boats knocked down too? It�s
a dangerous situation. This is the most serious discussion I�ve seen on the
group in my long career of four months. As of noon 3/7 I have decided to
recap your points & add a few notes & observations.
THERE WAS NOTHING INSIDE THE BOAT BUT 500 LBS OF SAND.
That�s an odd practice. Why didn�t you use water ballast & how exactly did
you know the sand weighed 500 lbs? Please assure us that none of it shifted.
MIZZEN LACES BROKE. PERHAPS THE SAIL WAS BAGGING. IT MADE IT HARD TO HEAD
UP.
If the mizzen was catching & bagging wind it should have aided heading up. I
suspect it was spilling. I know in that situation the MJ has lee helm and
wants to fall off, particularly if she is also slowing.
25 MPH WIND
Look, that is not a lot of wind. A boat that can�t use Force 6 is
unseaworthy. That�s a great sailing wind.
MAIN WAS UNCLEATED AND LUFFING.
I have been bothered by the MJ�s mainsail. Uncleated in those conditions she
is in danger of tripping over her boom when the clew hits the water. Bolger
warns of this. In addition, when she luffs down where you are looking at
her, her yard may not necessarily be blowing out aloft. If the mainsail is
not reefed but full, this problem could be exacerbated by the standard
placement of the halyard sheave low on the aft side of the mast. If you hang
your lug rig to starboard, for example, then on a port tack you develop
considerable twist in the halyard fall. Maybe too much twist if the fall is
very short.
The cure, I suggest, and which I have installed on my own MJ, is to raise
the sheave some (mine hangs within 12� of the mast peak), and to reef my
boat clew to clew instead of the usual Marconi system of tack to tack. That
shoots the boom forward each time you tuck one. Bolger recommends this
system for our boat, even though it is one or two motions extra.
HULL WINDAGE KNOCKED HER DOWN TOO EASILY.
All boats give you a feeling of surrender when they at last capsize after
heeling further and further. But hull windage? An MJ is high-sided, but
remember that her sides are aslant to deflect the wind with little for it to
grab when she heels. Nearly every other boat out there, including all your
roundbottom dinghies and clorox bottle types throw up much more beam when
they heel, and their shape tends far more to catch the wind in the
underbody. It�s a long way over before the MJ shows any underbody at all.
This is a common misconception about the factor of boat windage. Most people
assume a high sided boat has more windage than a low sided boat. Wrong.
Windage is a factor of beam, not freeboard, under the conditions you are
describing. Topside it is very much a factor of standing rigging.
WIND PRESSURE ON THE BOTTOM PUSHED HER DOWN UNTIL SHE FLOODED THROUGH THE
COMPANIONWAY AND DROVE THE MAST UNDER TO STICK FAST IN THE MUD (like a
Chinese pole anchor).
I am not sure when I read this whether the culprit was wind pressure or
gravity. It sounds like your mast sank on her own, too quickly at any rate.
It should take a lot more than a Force 6 breeze to push a buoyant mast and
semibuoyant sails under at such an angle that a 20� spar finds at 9� lake
bottom. And all this while fighting against the righting moment of 500 lbs
of sand bags. Something is very wrong here. A non-buoyant, too heavy mast
would explain an awful lot of your boat behavior.
TRIPPED OVER THE LEEBOARD.
Since it is impossible to go to windward without an extended board (under
any conditions), and it is impossible to raise a board when you think the
boat is going to capsize, there�s no point in discussing this as an option.
It�s about like saying you should furl the mainsail if the think the boat is
capsizing. Leeboards, centerboards, fixed keels, whatever, I don�t think
their shapes or positions have anything to do with your/our solution.
LEEBOARDS TOO WIDE FOR QUICK STEERING.
I disagree completely, comparisons with the Sea Pearl notwithstanding. Not
at all my experience.
2 HP HONDA OVERPOWERED.
That�s a small engine, all right, but have you explained that you have a
non-standard self-designed transom-hung rudder? It could be the little
engine was fighting that more than it was the wind. But again, no proper
sailboat needs an engine to avoid capsize.
SAIL DOUBLE-REEFED, YARD AND MAST (? don�t you mean boom?) SET LOW.
With mizzen set and probably bagging terribly at the same time the clew end
of the boom was hitting the water, it might be that we can explain this one.
WENT DOWN NICELY TO LIE FLAT WITH THE HATCH ABOVE WATER UNTIL WIND PRESSURE
MADE HER TURTLE.
Again, look at that mast as the culprit. Catamarans go turtle when their
masts fill up with water. Yours, whatever material, does not sound very
buoyant or very light.
WAVES SMALL.
Should not be a factor anyway.
WANT TO ADD FOAM.
The locations you suggest are all low. Foam needs to go high. The best
place, unfortunately, is the peak of the mast. Otherwise, under the cabin
top, maybe under the cockpit seats. But, Steve, your boat floated fine with
no foam at all and 500 lbs of negative ballast in sand.
TRAPPED AIR UNDER COCKPIT.
When the swamped boat is rolled upright, it stands to reason her mast weight
will push her down forward while her cockpit seats will provide plenty of
low buoyancy aft. The cabin top out of the water is more negative buoyancy
forward. It is unlikely if she lay on her side awhile she trapped any air
aft.
On the other hand, did you furl the sails or drop the mast?
�WHAT I�D REALLY LIKE IS ONE MORE FOOT OF BEAM�
Maybe so, but that�s a foot more windage and a foot more stability turtled.
WENT SLOWLY FROM 45 TO 90.
One more factor that makes me strongly suspect your ballast was working but
your mast weight was working harder.
GLAD MY DAUGHTER WASN�T IN THE CABIN.
This is where the discussion gets very serious & as an MJ owner I am pretty
upset about the implications. As she sits, your boat is too dangerous to put
out in any conditions. And maybe mine is too. That said, it sounds like
passengers, as you describe the situation, would have had ample time to
evacuate before the wind, as you said, pushed her down. On the other hand,
what if the hatch had been closed? It might have been difficult to open. Who
knows? And by the time it was opened, water might have been rushing in.
TO SUM UP, my computer (the one I carry on my shoulders) says your boat
displays every indication that you have a mast & sails made of solid lead or
maybe even plutonium. Check the label. But all Marthas seem to be too
sluggish in saving themselves, so it�s time to canvas the fleet & map out
some good ways to improve her snap in recovery.
Ed Haile
______________________________________________________