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Foam-filled mast
Assuming one makes provision to access and mechanical or electrical
components within the mast, are there any compelling reasons NOT to foam fill the mast? Bob Swarts |
Foam-filled mast
On Sun, 16 Oct 2005 08:01:04 -0700, Robert or Karen Swarts wrote:
Assuming one makes provision to access and mechanical or electrical components within the mast, are there any compelling reasons NOT to foam fill the mast? Bob Swarts There could be weight and righting moment issues. Maybe it will be OK, but I guess I would at least want to do the math before I poured the foam... There could be possible corrosion problems. Hollow masts are pretty resistant to oxidation. If you fill it with foam it could easily develop pockets of poor drainage, and therefore corrode. --Mac |
Foam-filled mast
On Sun, 16 Oct 2005 08:01:04 -0700, "Robert or Karen Swarts"
wrote: Assuming one makes provision to access and mechanical or electrical components within the mast, are there any compelling reasons NOT to foam fill the mast? Bob Swarts Hmmm...why foam fill? If wood, it might preserve from water damage.... If metal, might dampen halliard slapping noise.... Or is there some other purpose - not strength, I don't think Brian |
Foam-filled mast
I would guess it all depends on YOUR defilation of 'foam'.
When this question comes up there are usually references to ' . . .pouring foam . . .'. I would absolutely NOT use any of the 2-part 'Pour-in-Place' foams. Your are really in it, as regards solutions to 'What if . . .?' problems. What I think of in this situation is the foam 'Swim Noodles' or big blocks of Styrofoam. Cut to roughly 'rod shape' about the ID of the mast. Just shove them into place with a long piece of 1x1 or lengths of 1in PVC. The reasoning behind ANY foam or flotation material is to fill AIR SPACE. It is the AIR that gives the actual buoyancy. That's why they designate the 'Marine' foam as '2 pound', '3 pound', etc. That means that for each cubic foot, the foam weighs 2 pounds, etc. Therefore, when calculating buoyancy . .. . a cubic foot of water {there is a slight difference between Salt and Fresh}weighs about 62 pounds MINUS the weight of the foam EQUALS the ability to support 60 pounds per cubic foot of that particular material. Regards & Good Luck, Ron Magen Backyard Boatshop "Robert or Karen Swarts" wrote in message ... Assuming one makes provision to access and mechanical or electrical components within the mast, are there any compelling reasons NOT to foam fill the mast? Bob Swarts |
Foam-filled mast
I give up ... why would anyone fill a mast with "foam"?
"Robert or Karen Swarts" wrote in message ... Assuming one makes provision to access and mechanical or electrical components within the mast, are there any compelling reasons NOT to foam fill the mast? Bob Swarts |
Foam-filled mast
Primary reason is that it increases righting moment in the event of a
capsize. I suppose it might also keep the mast from sinking in case of a demasting. Might make the mast marginally stronger if completely filled. I also misspoke in this area in that what I was envisioning was plugging the mast with foam rather than completely filling it. BS "Bowgus" wrote in message ... I give up ... why would anyone fill a mast with "foam"? "Robert or Karen Swarts" wrote in message ... Assuming one makes provision to access and mechanical or electrical components within the mast, are there any compelling reasons NOT to foam fill the mast? Bob Swarts |
Foam-filled mast
Robert or Karen Swarts wrote:
Assuming one makes provision to access and mechanical or electrical components within the mast, are there any compelling reasons NOT to foam fill the mast? About the only foam you would ever consider placing inside a mast would be blocks of soft furniture foam for the purpose of quieting any wires inside the mast that might be slapping the mast. IMHO, the result is almost the biggest PITA on the planet. Been there, done that. A good messenger cable makes the problem go away. Lew |
Foam-filled mast
On Sun, 16 Oct 2005 15:39:19 -0700, "Robert or Karen Swarts"
wrote: Primary reason is that it increases righting moment in the event of a capsize. I suppose it might also keep the mast from sinking in case of a demasting. Might make the mast marginally stronger if completely filled. I also misspoke in this area in that what I was envisioning was plugging the mast with foam rather than completely filling it. Bingo... An inversion may cause the mast to fill with water, and depending on the diameter and lenght of mast, the the leverage weight at or near the masthead would be significant. I think 1square foot of water is about 64 lbs. Or about 1 gallon of water is about 8lbs... Anyone know what the leverage force would be needed to lift 64lbs at 30ft of leverage from the folcrum point? That may not be exactly the right question... I would not recommend filling the complete void in the mast, but sealing of the mast might be considered. As this was a suggestion by someone making their boat 'bluewater' ready as just one of the things they would do. Also if the mast is buoyant then it could help the righting momentum. BS "Bowgus" wrote in message ... I give up ... why would anyone fill a mast with "foam"? "Robert or Karen Swarts" wrote in message ... Assuming one makes provision to access and mechanical or electrical components within the mast, are there any compelling reasons NOT to foam fill the mast? Bob Swarts |
Foam-filled mast
I did it because I was going insane from the constant chiming noise something inside the mast was making snip styrofoam peanuts. Bob Swarts That makes sense ... and I suppose foam would have solved that particular noise problem. A very long application tube would be required initially I would think, to be withdrawn as the mast was filled, to ensure complete filling. But "Rob or Karen" did then say just to plug the mast. Home Depot here sells what's called Hotstuff (I think) foam in aerosol cans for home insulating .... but I don't know that it would provide the desired waterproof/airproof seal. Easy enough to find out though I guess ... plug the mast, head out to deep water and chuck the mast overboard ... "Rob or Karen" ... let us know how that works out :-) |
Foam-filled mast
Locally at least, it's called "Great Stuff." Be advised that it is
incredibly sticky (wear disposable gloves) and that it continues to expand slowly, with significant force, for weeks after it's applied. It is waterproof and airtight. I don't think I'd use it on a mast except maybe for plugs at each end. Less is better. Once you've used part of a can, it's really difficult to come back later for a second task, kinda like 3M 5200 except the problem is the plugged applicator tube and valve. The solidified foam turns brown and crumbly when exposed to sunlight for any length of time. Roger http://home.earthlink.net/~derbyrm "Bowgus" wrote in message .. . I did it because I was going insane from the constant chiming noise something inside the mast was making snip styrofoam peanuts. Bob Swarts That makes sense ... and I suppose foam would have solved that particular noise problem. A very long application tube would be required initially I would think, to be withdrawn as the mast was filled, to ensure complete filling. But "Rob or Karen" did then say just to plug the mast. Home Depot here sells what's called Hotstuff (I think) foam in aerosol cans for home insulating ... but I don't know that it would provide the desired waterproof/airproof seal. Easy enough to find out though I guess ... plug the mast, head out to deep water and chuck the mast overboard ... "Rob or Karen" ... let us know how that works out :-) |
Foam-filled mast
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Foam-filled mast
OK, with my28' S2 with 48' mast, the max righting torque I calculate is
about 4500 ft-lbs. For comparison, the torque produced by the 3300 lb keel is about 9900 ft-lbs. Now, for using expanding foam to silence internal halyard slap: With mast down drill holes at 3' intervals, make the holes about 1/4" to avoid stress cracking around smaller holes. Inject enough expanding foam. While it sets over a few hours, work the halyards back and forth. With mast UP. go up[ bosuns chair, drill 1/4" holes. Put a small balloon through the holes and inflate. Push the nozzle of the expanding foam in beside the balloon and above it. Inject foam. The balloon is there to keep the foam from just dropping down to the bottom. There are various versions of expanding foam, some exerts a lot of force/area and can push things out of alignment (not an issue here) and a less strong version intended for insulating around windows that would also work in this app. |
Foam-filled mast
Sounds scary to me. That stuff BONDS! Working the halyards may mean they
aren't anchored to the mast, but if the line is adorned with blobs, it probably won't pass thru the sheaves freely. When I spoke of the continued, forcible expansion, I was referring to the cans labeled "minimal expansion." Roger http://home.earthlink.net/~derbyrm wrote in message oups.com... snip Now, for using expanding foam to silence internal halyard slap: With mast down drill holes at 3' intervals, make the holes about 1/4" to avoid stress cracking around smaller holes. Inject enough expanding foam. While it sets over a few hours, work the halyards back and forth. |
Foam-filled mast
I can think of two reason not to fill your aluminum mast with foam.
1. Strange things can happen to uncoated aluminum it is prevented from oxidizing naturally. (never been a need to paint the inside of a mast in all these years) 2. In open water, rough seas, I don't think I would want a floating mast along side. I would prefer that it fill with water and hang below the boat until the rigging wires can be cut away. It is bad enough when the sails trap air and keep the mast and boom at or near the surface. Like a battering ram. I have experienced two de-masting in 45 years of sailing and the most damage I have noted (aside from the mast) has been to the hull at the water line due to the floating mast. (once with a solid wooden mast and once with an aluminum). -- My experience and opinion, FWIW -- Steve s/v Good Intentions "Robert or Karen Swarts" wrote in message ... Primary reason is that it increases righting moment in the event of a capsize. I suppose it might also keep the mast from sinking in case of a demasting. Might make the mast marginally stronger if completely filled. I also misspoke in this area in that what I was envisioning was plugging the mast with foam rather than completely filling it. BS "Bowgus" wrote in message ... I give up ... why would anyone fill a mast with "foam"? "Robert or Karen Swarts" wrote in message ... Assuming one makes provision to access and mechanical or electrical components within the mast, are there any compelling reasons NOT to foam fill the mast? Bob Swarts |
Foam-filled mast
On Sun, 16 Oct 2005 15:39:19 -0700, Robert or Karen Swarts wrote:
Primary reason is that it increases righting moment in the event of a capsize. I suppose it might also keep the mast from sinking in case of a demasting. Assuming the boat is designed well, the keel will give it all the righting moment it needs. And as far as I know, if the mast comes off of the boat, you don't want it hanging around. If this is a catamaran, then putting a float at the very top of the mast might be a good idea. Or at least I have seen some smaller catamarans with such things on them. Might make the mast marginally stronger if completely filled. Maybe. Maybe not. It certainly won't increase the compression strength. Anyway, this doesn't seem to be a compelling reason. I also misspoke in this area in that what I was envisioning was plugging the mast with foam rather than completely filling it. BS In my opinion, you want the bottom and top of the mast to be as wide open as reasonably possible. That way, after a capsize, as the boat starts to right itself, the mast will drain readily (assuming it is still attached to the deck). I don't think there is any way you can seal a mast with internal halyards sufficiently so that it won't fill up with water when the boat is upside down. If you attempt to do this, and the mast does fill with water, it will be even harder for the boat to right itself, because the water will drain out of the mast more slowly. If anything, you would want to put extra holes or slots in the mast all along its length so that the water can drain out fast. --Mac "Bowgus" wrote in message ... I give up ... why would anyone fill a mast with "foam"? "Robert or Karen Swarts" wrote in message ... Assuming one makes provision to access and mechanical or electrical components within the mast, are there any compelling reasons NOT to foam fill the mast? Bob Swarts |
Foam-filled mast
An inversion may cause the mast to fill with water, and depending on
the diameter and lenght of mast, the the leverage weight at or near the masthead would be significant. I think 1square foot of water is about 64 lbs. Or about 1 gallon of water is about 8lbs... Cubic foot. One square foot of water has a weight of zero. :) Anyone know what the leverage force would be needed to lift 64lbs at 30ft of leverage from the folcrum point? That may not be exactly the right question... Approx. 3000Nm, but that's irrelevant: Assume inversion. The mast will first be underwater. Then the water in the mast has neutral buoyancy. To get out of the inversion, the boat uses hull shape and keel weight, if not a racer designed to remain stable in an upside down position. But these have escape hatches on the bottom. :) Once the mast is parallel to the water surface, the keel has the best angle of attack to righten it. Much more than during strongly heeled sailing, i.e. a few gallons of water at the mast top won't do anything. Not even a few hundred pounds. If you want easier proof: You can hoist a person up the mast of even small keeboats witout inverting them. Chris |
Foam-filled mast
On 26 Oct 2005 23:23:21 -0700, "Chris" wrote:
/// Not even a few hundred pounds. If you want easier proof: You can hoist a person up the mast of even small keeboats witout inverting them. Chris Can you hoist a person up a mast at 60 degrees to the vertical, without a capsize? Brian Whatcott |
Foam-filled mast
Several years ago, at the first Atlantic City Sailboat Show I think, there
was a 'solution' to this problem. The Geougeon Brothers {the WEST System people - forgive the spelling} were manufacturing a 'large' catamaran {I don't know if they still are} at the time. Anyway, as I was walking about the hall I noticed what looked like a miniature 'blimp' {about 3-4 feet long} above the field of masts. It had their name on it and that's what I thought it was - an airborne advertisement. As I got closer, I saw that it was actually attached to the top of the mast of their catamaran . . . but still thought of it as an advert. I soon found out that it was really a piece of 'Safety Gear'. The shape was for aerodynamic reasons. A catamaran has 'Ultimate Stability' at TWO points .. . . completely upright AND completely upside down!! Having a sufficient quantity of extremely buoyant, and light weight, material at the end of a long attached moment arm reduces this to ONE. While you may experience a 'knock-down', you shouldn't be able to 'turtle'. OBVIOUSLY, it takes a great deal more material {or even air} then can be contained in the volume of the mast itself. Regards & Good Luck, Ron Magen Backyard Boatshop "Chris" wrote in message oups.com... An inversion may cause the mast to fill with water, and depending on the diameter and lenght of mast, the the leverage weight at or near the masthead would be significant. I think 1square foot of water is about 64 lbs. Or about 1 gallon of water is about 8lbs... Cubic foot. One square foot of water has a weight of zero. :) Anyone know what the leverage force would be needed to lift 64lbs at 30ft of leverage from the folcrum point? That may not be exactly the right question... Approx. 3000Nm, but that's irrelevant: Assume inversion. The mast will first be underwater. Then the water in the mast has neutral buoyancy. To get out of the inversion, the boat uses hull shape and keel weight, if not a racer designed to remain stable in an upside down position. But these have escape hatches on the bottom. :) Once the mast is parallel to the water surface, the keel has the best angle of attack to righten it. Much more than during strongly heeled sailing, i.e. a few gallons of water at the mast top won't do anything. Not even a few hundred pounds. If you want easier proof: You can hoist a person up the mast of even small keeboats witout inverting them. Chris |
Foam-filled mast
Let us suppose the mast is 4" in diameter and 25 ft long, stepped 4 ft above
waterline. The weight of water it displaces is 138 lb. Let us suppose half if that is the weight of the mast. That leaves 69 lb positive buoyancy. The center of buoyancy of the mast is about 16 ft above waterline. That will create a righting moment of about 1100 ft lb when the boat is flat on the water. That is not inconsequential, and could be a large help in preventing a total capsize. BS "Brian Whatcott" wrote in message ... On 26 Oct 2005 23:23:21 -0700, "Chris" wrote: /// Not even a few hundred pounds. If you want easier proof: You can hoist a person up the mast of even small keeboats witout inverting them. Chris Can you hoist a person up a mast at 60 degrees to the vertical, without a capsize? Brian Whatcott |
Foam-filled mast
Can you hoist a person up a mast at 60 degrees to the vertical, without a capsize? Well, with our imaginary boat w/ a 10m mast, 1.8m keel of 3000 lbs heeled so that the mast is flat on the water: (roughly a 27-footer, pivot boint between mast and keel in the center of the cabin, me on top of the mast.) Mast side: 200 lbs person * 10m = 1000N * 10m = 10,000 Nm Keel side: 3000 lbs Keel * 0.9m = 15,000N * 0.9m = 13,500 Nm Give and take a bit with the approximations, I'd say you can on a 27-footer if you are light and daring and for sure in anything larger than that. But then, in waves that tilt the boat 60 deg from vertical, I wouldn't want to be hoisted to the mast. And I'm afraid that in the waves that generate the ten housand ++ Nm to get the mast under water, the 1100 ft lb (is that approx. 1500 Nm?) mentioned in the next post are rather inconsequential. Not that I've ever tried it. :) Chris |
Foam-filled mast
On Thu, 27 Oct 2005 16:22:26 -0700, Robert or Karen Swarts wrote:
Let us suppose the mast is 4" in diameter and 25 ft long, stepped 4 ft above waterline. The weight of water it displaces is 138 lb. Let us suppose half if that is the weight of the mast. That leaves 69 lb positive buoyancy. The center of buoyancy of the mast is about 16 ft above waterline. That will create a righting moment of about 1100 ft lb when the boat is flat on the water. That is not inconsequential, and could be a large help in preventing a total capsize. BS [snip] This all seems very doubtful. I am not sure if you understand how dynamic the sea-state is in conditions likely to cause a knockdown in the first place. Maybe you should ask a real naval architect (marine engineer) about this. I think it is a very bad idea which you will regret if you do it, but I am not an expert. --Mac |
Foam-filled mast
This is not an original idea with me. I have seen it recommended in a couple
of articles/books on deep water sailing/boats. There is no disputing the math, although other factors do come into it. BS "Mac" wrote in message ... On Thu, 27 Oct 2005 16:22:26 -0700, Robert or Karen Swarts wrote: Let us suppose the mast is 4" in diameter and 25 ft long, stepped 4 ft above waterline. The weight of water it displaces is 138 lb. Let us suppose half if that is the weight of the mast. That leaves 69 lb positive buoyancy. The center of buoyancy of the mast is about 16 ft above waterline. That will create a righting moment of about 1100 ft lb when the boat is flat on the water. That is not inconsequential, and could be a large help in preventing a total capsize. BS [snip] This all seems very doubtful. I am not sure if you understand how dynamic the sea-state is in conditions likely to cause a knockdown in the first place. Maybe you should ask a real naval architect (marine engineer) about this. I think it is a very bad idea which you will regret if you do it, but I am not an expert. --Mac |
Foam-filled mast
Mac wrote:
On Thu, 27 Oct 2005 16:22:26 -0700, Robert or Karen Swarts wrote: Let us suppose the mast is 4" in diameter and 25 ft long, stepped 4 ft above waterline. The weight of water it displaces is 138 lb. Let us suppose half if that is the weight of the mast. That leaves 69 lb positive buoyancy. The center of buoyancy of the mast is about 16 ft above waterline. That will create a righting moment of about 1100 ft lb when the boat is flat on the water. That is not inconsequential, and could be a large help in preventing a total capsize. BS [snip] This all seems very doubtful. I am not sure if you understand how dynamic the sea-state is in conditions likely to cause a knockdown in the first place. Maybe you should ask a real naval architect (marine engineer) about this. I think it is a very bad idea which you will regret if you do it, but I am not an expert. --Mac It seems, if you are worried, that if the mast is reasonably tight, it would not flood immediately after being whipped into the water. It's speed of descent would provide a great deal of drag through water to decellerate the rolling momentum, and would provide some righting bouyancy until it filled. Sealing a mast may be impossible, but slowing its flooding, possibly with external halyards and a wad of foam or some pop bottles and even pumping it once horizontal with a small hose to the mast head, might be a better plan, strange as it sounds. Once on it's side, a keel boat will want to right itself, until it fills with water. Keep the properly designed companionway bottom board in place. On a trampoline / catamaran, you will want righting accessories like possibly a self inflating "Mae West" at the masthead. 200 lbs bouyancy might to, and that is about 1.5 cubic feet of balloon, 10 pounds of tennis balls? Many catamarans have servicable rope loops rigged, to enable overboard capsized crew to pull the boat upright once it has landed on it's side. They take a moment or three to turtle after resting on their sides, with the mast flooding and because of their geometry, wanting to continue rolling inverted. The floating mast is their only hope, however faint. The dynamics of weather tending to capsize the boat will be greatly diminished, once you come to a stop and the sails are horizontal on the water. The sail itself would prevent rapid sinking of the mast, if it did not simply tear, sheeted in. The mast may well break open. Dare I suggest floating line shrouds as an adjunct, or even a floating, sealed at the ends hollow wooden mast? Once turtled, a long enough halyard or spare detached from the sail head and "lowered" from it's submerged cleat now only a foot or so submerged, brought to the surface athwartships, can haul the boat back upright, if enough bouyancy and counterweight can be found amongst swimming crew with lifejackets, coolers, floating cushions, gas tanks, rescue assist vessels, and whatever. Flooding one completely upside down cat hull to make it sink so the boat is suspended by one floating hull also helps. Once it is a little more downwind than the floating hull, raising it is easier, since all you need do is counterbalance the submerged, reduced weight and especially, the mast, once horizontal at the waters surface, and which, we hope, is still trying to float, at least a little. Pumping the submerged hull will right the boat. Crossed hull pumping lines and a pump tied on to avoid it's loss, able to inflate the hull with air or extract water complete the scheme. Such serious righting arrangements are able and can be seen on serious cats if you ask their skippers. Flooding the hull may seem difficult, but an "air syphon" hose will do it easily and dependably, if a hatch can be opened aside from this air vent / pumping hose. One would hope the design permits a loaded cruising cat to still float, even with one hull full of water, purposely flooded. Small cats are a natural, larger ones will want bouyancy compartments sufficient to minimally float the boat even when capsized and flooding if the companionway hatches are not watertight. Just one more reason to keep those through hulls closed, eh? Terry K |
Foam-filled mast
On Fri, 28 Oct 2005 07:46:14 -0700, Robert or Karen Swarts wrote:
This is not an original idea with me. I have seen it recommended in a couple of articles/books on deep water sailing/boats. There is no disputing the math, although other factors do come into it. BS Well, there have been many bad ideas published over the years, I'm sure. But anyway, a mast filled with air and submerged will have more buoyancy than one filled with water. And that buoyancy will, all things considered, have a tendency to right the boat. I don't dispute that at all. I am just asking the question "What effect is there on the chances of righting your boat when your 'sealed' mast fills up with water which then can't easily escape?" Because I fear that the mast may stay submerged long enough to fill up. Anyway, I don't think I have anything new to say on the subject. Maybe you could put flapper valves on the mast so water can't come in, but can get out at the mast head, and air can't get out but can get in at the mast's base? ;-) --Mac "Mac" wrote in message ... On Thu, 27 Oct 2005 16:22:26 -0700, Robert or Karen Swarts wrote: Let us suppose the mast is 4" in diameter and 25 ft long, stepped 4 ft above waterline. The weight of water it displaces is 138 lb. Let us suppose half if that is the weight of the mast. That leaves 69 lb positive buoyancy. The center of buoyancy of the mast is about 16 ft above waterline. That will create a righting moment of about 1100 ft lb when the boat is flat on the water. That is not inconsequential, and could be a large help in preventing a total capsize. BS [snip] This all seems very doubtful. I am not sure if you understand how dynamic the sea-state is in conditions likely to cause a knockdown in the first place. Maybe you should ask a real naval architect (marine engineer) about this. I think it is a very bad idea which you will regret if you do it, but I am not an expert. --Mac |
Foam-filled mast
On Fri, 28 Oct 2005 16:59:19 -0300, Terry Spragg wrote:
Mac wrote: On Thu, 27 Oct 2005 16:22:26 -0700, Robert or Karen Swarts wrote: Let us suppose the mast is 4" in diameter and 25 ft long, stepped 4 ft above waterline. The weight of water it displaces is 138 lb. Let us suppose half if that is the weight of the mast. That leaves 69 lb positive buoyancy. The center of buoyancy of the mast is about 16 ft above waterline. That will create a righting moment of about 1100 ft lb when the boat is flat on the water. That is not inconsequential, and could be a large help in preventing a total capsize. BS [snip] This all seems very doubtful. I am not sure if you understand how dynamic the sea-state is in conditions likely to cause a knockdown in the first place. Maybe you should ask a real naval architect (marine engineer) about this. I think it is a very bad idea which you will regret if you do it, but I am not an expert. --Mac It seems, if you are worried, that if the mast is reasonably tight, it would not flood immediately after being whipped into the water. It's speed of descent would provide a great deal of drag through water to decellerate the rolling momentum, and would provide some righting bouyancy until it filled. Sealing a mast may be impossible, but slowing its flooding, possibly with external halyards and a wad of foam or some pop bottles and even pumping it once horizontal with a small hose to the mast head, might be a better plan, strange as it sounds. Somehow I don't think anybody is going to be pumping a mast full of air in the conditions that cause a sea-worthy boat to get knocked-down. Once on it's side, a keel boat will want to right itself, until it fills with water. Keep the properly designed companionway bottom board in place. Are you under the impression that the bottom board will stay in place when this happens, or that water will only come up to the bottom board? In these conditions, the companionway (and all other hatches) need(s) to be completely closed. On a trampoline / catamaran, you will want righting accessories like possibly a self inflating "Mae West" at the masthead. 200 lbs bouyancy might to, and that is about 1.5 cubic feet of balloon, 10 pounds of tennis balls? Many catamarans have servicable rope loops rigged, to enable overboard capsized crew to pull the boat upright once it has landed on it's side. They take a moment or three to turtle after resting on their sides, with the mast flooding and because of their geometry, wanting to continue rolling inverted. The floating mast is their only hope, however faint. The dynamics of weather tending to capsize the boat will be greatly diminished, once you come to a stop and the sails are horizontal on the water. The sail itself would prevent rapid sinking of the mast, if it did not simply tear, sheeted in. The mast may well break open. By and large, it is the sea which capsizes boats, not the wind. Dare I suggest floating line shrouds as an adjunct, or even a floating, sealed at the ends hollow wooden mast? Once turtled, a long enough halyard or spare detached from the sail head and "lowered" from it's submerged cleat now only a foot or so submerged, brought to the surface athwartships, can haul the boat back upright, if enough bouyancy and counterweight can be found amongst swimming crew with lifejackets, coolers, floating cushions, gas tanks, rescue assist vessels, and whatever. Flooding one completely upside down cat hull to make it sink so the boat is suspended by one floating hull also helps. Once it is a little more downwind than the floating hull, raising it is easier, since all you need do is counterbalance the submerged, reduced weight and especially, the mast, once horizontal at the waters surface, and which, we hope, is still trying to float, at least a little. Pumping the submerged hull will right the boat. Crossed hull pumping lines and a pump tied on to avoid it's loss, able to inflate the hull with air or extract water complete the scheme. Such serious righting arrangements are able and can be seen on serious cats if you ask their skippers. I have heard of this business. I've never heard of anybody using it at sea after a capsize. Have you? Please be specific because I would love to read about it. Also, I have to point out that it would probably be impossible to do this until days after the storm subsides. Flooding the hull may seem difficult, but an "air syphon" hose will do it easily and dependably, if a hatch can be opened aside from this air vent / pumping hose. Flooding a hull seems easy, to me. Floating it afterwards would prove difficult. One would hope the design permits a loaded cruising cat to still float, even with one hull full of water, purposely flooded. Small cats are a natural, larger ones will want bouyancy compartments sufficient to minimally float the boat even when capsized and flooding if the companionway hatches are not watertight. Just one more reason to keep those through hulls closed, eh? Terry K I don't know, Terry. I am not opposed to these types of measures, but it is important to understand what the capabilities of a crew are really likely to be in the kinds of conditions we are talking about. The best bet is to make sure that the boat doesn't sink during the storm, and try to jury rig something to get you to the nearest port after the storm is over. After you feel comfortable that the boat can be kept afloat indefinitely (you hope), when being knocked-down repeatedly or even capsized, then you can think about other measures such as buoyant masts and air-pumps for floating hulls and so-on. Just my $0.02. --Mac |
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