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#1
posted to rec.boats.cruising
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Peter HK wrote:
"sherwindu" wrote in message ... One question nobody has addressed yet is what happens when a cat capsizes? There is no natural righting moment, as with a mono hull. I have never even sailed on a cat myself, but the heeling of a mono hull seems to offer some comfort advantages, because the combination of sails and pendulum keel act as a kind of 'shock absorber' in wavy conditions. I would prefer to be heeled over and on a steady lean than bounced up and down as one than another hull is lifted and dropped by a wave, especially in short choppy seas. Long rolling waves would probably somewhat nullify this advantage. I am referring more to waves on the beam, but there probably is some effect on a close hauled tack. Sherwin D. There are occasional sea patterns that are uncomfortable on a multi, usually with beam seas, but the magnitude of the event needs to be considered. Cats reach max stability at about 5 degrees of heel (when a hull lifts). As this never happens on cruising cats, all heel angles are less than 5 degrees. Short sharp waves can occasionally exceed this a little due to the hulls being in a trough and crest. Compare to a mono rolling downwind where heel angles can be 30 degrees side to side. Multis do have a different motion- shorter and sharper compared to slower but much more amplitude on a mono. Personally I find it quite comfortable. As stated in a previous post a glass never spills, which is a significant observation on the severity of the motion. When a multi capsizes it floats- most are now equipped with hatches to enter a secure part of the hull in a capsize. When a mono sinks however- dragged down by that ballast that makes it self-righting- the only hope is a liferaft. It depends on what you think is the most basic safety feature- nonsinkability or self righting. Peter HK I guess most people prefer to be upside-down-but-floating compared to upright-on-the-bottom of the Atlantic. The next question though, is what are chances of such events to happen? When I cross the Atlantic (or whatever waters) I rather opt for a 1% chance to sink my monohull (and trust on my liferaft) than a 20% chance of capsizing my cat. Now, both figures are probably far from accurate, so my question is, what are chances that such things will happen? Regards, Marc www.marineyacht.com |
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#2
posted to rec.boats.cruising
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"Marc Onrust" wrote in message . nl... I guess most people prefer to be upside-down-but-floating compared to upright-on-the-bottom of the Atlantic. The next question though, is what are chances of such events to happen? When I cross the Atlantic (or whatever waters) I rather opt for a 1% chance to sink my monohull (and trust on my liferaft) than a 20% chance of capsizing my cat. Now, both figures are probably far from accurate, so my question is, what are chances that such things will happen? Regards, Marc www.marineyacht.com The only published figure that I have ever seen for risk was in Chris White's book- The Cruising Multihull. He quotes mortality figures from the US coastguard over a 10 year period and tries to interpret mono and multi separately. Thus, while not capsize versus sinking, it was an attempt to look at overall risk. His estimate is one death per year per 16,500 multis compared to one per year per 12,500 monos. He admits the figures are not rock solid. Overall though it points to very low and equivalent risk in either hullform. Peter HK |
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#3
posted to rec.boats.cruising
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"Marc Onrust" wrote in message
. nl... Peter HK wrote: "sherwindu" wrote in message ... One question nobody has addressed yet is what happens when a cat capsizes? There is no natural righting moment, as with a mono hull. I have never even sailed on a cat myself, but the heeling of a mono hull seems to offer some comfort advantages, because the combination of sails and pendulum keel act as a kind of 'shock absorber' in wavy conditions. I would prefer to be heeled over and on a steady lean than bounced up and down as one than another hull is lifted and dropped by a wave, especially in short choppy seas. Long rolling waves would probably somewhat nullify this advantage. I am referring more to waves on the beam, but there probably is some effect on a close hauled tack. Sherwin D. There are occasional sea patterns that are uncomfortable on a multi, usually with beam seas, but the magnitude of the event needs to be considered. Cats reach max stability at about 5 degrees of heel (when a hull lifts). As this never happens on cruising cats, all heel angles are less than 5 degrees. Short sharp waves can occasionally exceed this a little due to the hulls being in a trough and crest. Compare to a mono rolling downwind where heel angles can be 30 degrees side to side. Multis do have a different motion- shorter and sharper compared to slower but much more amplitude on a mono. Personally I find it quite comfortable. As stated in a previous post a glass never spills, which is a significant observation on the severity of the motion. When a multi capsizes it floats- most are now equipped with hatches to enter a secure part of the hull in a capsize. When a mono sinks however- dragged down by that ballast that makes it self-righting- the only hope is a liferaft. It depends on what you think is the most basic safety feature- nonsinkability or self righting. Peter HK I guess most people prefer to be upside-down-but-floating compared to upright-on-the-bottom of the Atlantic. The next question though, is what are chances of such events to happen? When I cross the Atlantic (or whatever waters) I rather opt for a 1% chance to sink my monohull (and trust on my liferaft) than a 20% chance of capsizing my cat. Now, both figures are probably far from accurate, so my question is, what are chances that such things will happen? Regards, Marc www.marineyacht.com I don't think I recall hearing about any cruising cats that have capsized. Where are you getting 20% or even 5%? -- "j" ganz @@ www.sailnow.com |
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#4
posted to rec.boats.cruising
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Capt. JG wrote:
I guess most people prefer to be upside-down-but-floating compared to upright-on-the-bottom of the Atlantic. The next question though, is what are chances of such events to happen? When I cross the Atlantic (or whatever waters) I rather opt for a 1% chance to sink my monohull (and trust on my liferaft) than a 20% chance of capsizing my cat. Now, both figures are probably far from accurate, so my question is, what are chances that such things will happen? Regards, Marc www.marineyacht.com I don't think I recall hearing about any cruising cats that have capsized. Where are you getting 20% or even 5%? Incidences of cruising cats are pretty infrequent. I only know of the following; - PDQ 32 capsizing while entering a cut in the Bahamas while a "rage" was blowing. Pitchpoled in very shallow water in the huge breakers - a Gemini capsizing in Texas; sailed over due to too much sail - a Fountaine Pajot 35 capsized in the Caribbean; sailed over with a charter group aboard - a Catana in the Med; capsized due to a sudden squall hitting with the chute up at night. - a Heavenly Twins 26 or 27 capsizing in Force 10+ north of the British Isles during a rare summer severe storm. I have also heard of the F-P Maldives 32 being pretty susceptible to capsize but that's more innuendo that actual facts and the Iriquois but I don't know if they were capsized during racing or while cruising. Most of the above are smaller, narrower beam cats by the way of fairly old design; the exceptions being the FP 35 and the Catana. When the Wolfson Unit of Southhampton University did a study of trying to capsize cruising cat models the only way they could do it was a beam on breaking wave beam of the boat (similar to a monohull by the way) "MODEL TESTS TO STUDY CAPSIZE AND STABILITY OF SAILING MULTIHULLS" Deakin B. The 15th Chesapeake Sailing Yacht Symposium, January 2001 Evan Gatehouse |
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#5
posted to rec.boats.cruising
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Evan Gatehouse wrote:
.... Incidences of cruising cats are pretty infrequent. I only know of the following; - PDQ 32 capsizing while entering a cut in the Bahamas while a "rage" was blowing. Pitchpoled in very shallow water in the huge breakers I talked at length to the owner of this boat shortly after the episode. Apparently, the charterer was singlehanding, on autopilot, and down below. He was carrying full sail (one report said one turn on the jib) in 25+ knots, sheeted in tight, while on a beam reach. He was not entering, but passing by a notoriously windy cut in the Abacos (by Whale Cay?) and got hit by an estimated 45 knot gust and 6 foot wave beam on. The boat did not pitchpole, but slowly went on its side, and stayed there for several hours while the owner (who came from Marsh Harbor?) and others tried to right it. Finally, a stay broke and it capsized. It was towed back to Marsh Harbor where the deck was trashed by efforts to lift it inverted with slings. I saw the boat in Toronto awaiting a deck rebuild. One design factor considered by cat builders is how much wind could a boat handle in such a worst case of a gust on the beam with full sail sheeted in. The figure used for the PDQ 32 is 45 knots. The assumption is that in almost all cases where 45 knots is possible, you would shorten sail - even a single reef makes a huge difference in this situation. Also, in most cases someone would be on deck to release a sheet. A significant lesson is that whenever full sail is sheeted in during a blow, someone must be on deck! Two other factors apply he First, this particular boat was sailing "light." That is, it was stripped out and not carrying cruising gear. If it were loaded, it probably would not have gone over. The second is that this design has a rather narrow beam, coupled with a tall profile. This is one of the issues with smaller cats, since the temptation by designers is to make them narrow enough for a slip. Also, since the bridge deck clearance and overhead boom height have practical minimums, smaller cats have proportionally taller rigs. The combination of narrow beam and tall rig makes this sort of incident inevitable. For this reason, I've usually said that the minimum size for an offshore capable cat is about 35 feet, unless it has a very conservative rig. This situation also applies to the Gemini (14 foot beam), and a recent case of an Iroquois (which only has a 13 foot beam!). The Heaven Twins is another such case, with a beam under 14 feet. - a Gemini capsizing in Texas; sailed over due to too much sail - a Fountaine Pajot 35 capsized in the Caribbean; sailed over with a charter group aboard - a Catana in the Med; capsized due to a sudden squall hitting with the chute up at night. - a Heavenly Twins 26 or 27 capsizing in Force 10+ north of the British Isles during a rare summer severe storm. I have also heard of the F-P Maldives 32 being pretty susceptible to capsize but that's more innuendo that actual facts and the Iriquois but I don't know if they were capsized during racing or while cruising. Most of the above are smaller, narrower beam cats by the way of fairly old design; the exceptions being the FP 35 and the Catana. When the Wolfson Unit of Southhampton University did a study of trying to capsize cruising cat models the only way they could do it was a beam on breaking wave beam of the boat (similar to a monohull by the way) "MODEL TESTS TO STUDY CAPSIZE AND STABILITY OF SAILING MULTIHULLS" Deakin B. The 15th Chesapeake Sailing Yacht Symposium, January 2001 Evan Gatehouse |
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#6
posted to rec.boats.cruising
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Evan Gatehouse wrote:
... Incidences of cruising cats are pretty infrequent. I only know of the following; - PDQ 32 capsizing while entering a cut in the Bahamas while a "rage" was blowing. Pitchpoled in very shallow water in the huge breakers Another incident not on the list... 2 ~ 3 years ago a Gemini capsized in the Straights near Seattle. Boat was reportedly being sailed by a novice in squally weather. Jeff wrote: I talked at length to the owner of this boat shortly after the episode. Apparently, the charterer was singlehanding, on autopilot, and down below. He was carrying full sail (one report said one turn on the jib) in 25+ knots, sheeted in tight, while on a beam reach. That's not really good practice, is it? ![]() .... (snip for brevity) ... The combination of narrow beam and tall rig makes this sort of incident inevitable. For this reason, I've usually said that the minimum size for an offshore capable cat is about 35 feet, unless it has a very conservative rig. Have you read Tom F. Jones account of sailing thru an Atlantic hurricane in a 26' (IIRC) Wharram? That was most interesting. I think that cruising can be done in multihulls with a degree of safety depending on the skill & knowledge of the skipper... obviously the more he knows about the characteristics of his specific vessel, the better. Fresh Breezes- Doug King |
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#7
posted to rec.boats.cruising
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DSK wrote:
Evan Gatehouse wrote: ... Incidences of cruising cats are pretty infrequent. I only know of the following; - PDQ 32 capsizing while entering a cut in the Bahamas while a "rage" was blowing. Pitchpoled in very shallow water in the huge breakers Another incident not on the list... 2 ~ 3 years ago a Gemini capsized in the Straights near Seattle. Boat was reportedly being sailed by a novice in squally weather. Jeff wrote: I talked at length to the owner of this boat shortly after the episode. Apparently, the charterer was singlehanding, on autopilot, and down below. He was carrying full sail (one report said one turn on the jib) in 25+ knots, sheeted in tight, while on a beam reach. That's not really good practice, is it? ![]() No, but almost all disasters include some degree of human error, otherwise known as incompetence. When considering such events you have to think about what is possible when you screw things up; not what happens when you do everything perfectly. Of course, in this case its possible that a monohull would have lost its rig and have been in equally serious trouble. .... (snip for brevity) ... The combination of narrow beam and tall rig makes this sort of incident inevitable. For this reason, I've usually said that the minimum size for an offshore capable cat is about 35 feet, unless it has a very conservative rig. Have you read Tom F. Jones account of sailing thru an Atlantic hurricane in a 26' (IIRC) Wharram? That was most interesting. I think that cruising can be done in multihulls with a degree of safety depending on the skill & knowledge of the skipper... obviously the more he knows about the characteristics of his specific vessel, the better. I think I read that some time ago. When I wrote "conservative rig" I was thinking of Prouts and especially Warrams. |
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#8
posted to rec.boats.cruising
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"Jeff" wrote in message
news ![]() Evan Gatehouse wrote: ... Incidences of cruising cats are pretty infrequent. I only know of the following; - PDQ 32 capsizing while entering a cut in the Bahamas while a "rage" was blowing. Pitchpoled in very shallow water in the huge breakers I talked at length to the owner of this boat shortly after the episode. Apparently, the charterer was singlehanding, on autopilot, and down below. He was carrying full sail (one report said one turn on the jib) in 25+ knots, sheeted in tight, while on a beam reach. He was not entering, but passing by a notoriously windy cut in the Abacos (by Whale Cay?) and got hit by an estimated 45 knot gust and 6 foot wave beam on. The boat did not pitchpole, but slowly went on its side, and stayed there for several hours while the owner (who came from Marsh Harbor?) and others tried to right it. Finally, a stay broke and it capsized. It was towed back to Marsh Harbor where the deck was trashed by efforts to lift it inverted with slings. I saw the boat in Toronto awaiting a deck rebuild. One design factor considered by cat builders is how much wind could a boat handle in such a worst case of a gust on the beam with full sail sheeted in. The figure used for the PDQ 32 is 45 knots. The assumption is that in almost all cases where 45 knots is possible, you would shorten sail - even a single reef makes a huge difference in this situation. Also, in most cases someone would be on deck to release a sheet. A significant lesson is that whenever full sail is sheeted in during a blow, someone must be on deck! Two other factors apply he First, this particular boat was sailing "light." That is, it was stripped out and not carrying cruising gear. If it were loaded, it probably would not have gone over. The second is that this design has a rather narrow beam, coupled with a tall profile. This is one of the issues with smaller cats, since the temptation by designers is to make them narrow enough for a slip. Also, since the bridge deck clearance and overhead boom height have practical minimums, smaller cats have proportionally taller rigs. The combination of narrow beam and tall rig makes this sort of incident inevitable. For this reason, I've usually said that the minimum size for an offshore capable cat is about 35 feet, unless it has a very conservative rig. This situation also applies to the Gemini (14 foot beam), and a recent case of an Iroquois (which only has a 13 foot beam!). The Heaven Twins is another such case, with a beam under 14 feet. - a Gemini capsizing in Texas; sailed over due to too much sail - a Fountaine Pajot 35 capsized in the Caribbean; sailed over with a charter group aboard - a Catana in the Med; capsized due to a sudden squall hitting with the chute up at night. - a Heavenly Twins 26 or 27 capsizing in Force 10+ north of the British Isles during a rare summer severe storm. I have also heard of the F-P Maldives 32 being pretty susceptible to capsize but that's more innuendo that actual facts and the Iriquois but I don't know if they were capsized during racing or while cruising. Most of the above are smaller, narrower beam cats by the way of fairly old design; the exceptions being the FP 35 and the Catana. When the Wolfson Unit of Southhampton University did a study of trying to capsize cruising cat models the only way they could do it was a beam on breaking wave beam of the boat (similar to a monohull by the way) "MODEL TESTS TO STUDY CAPSIZE AND STABILITY OF SAILING MULTIHULLS" Deakin B. The 15th Chesapeake Sailing Yacht Symposium, January 2001 Evan Gatehouse I had an interesting experience sailing a Seawind 1000 on the SF bay a few years ago. It started out as a fairly typical day of 20 kts air. We were cruising along at about 12 kts, not really paying that much attention to the wind speed. Finally, I noticed that our speed had increased to about 14 kts, with large rooster tails off the back. Amazing stuff. Then, I realized that the wind speed had increased to 33 kts. Yikes... time to reef! .. which we did immediately. -- "j" ganz @@ www.sailnow.com |
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#9
posted to rec.boats.cruising
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Capt. JG wrote:
"Marc Onrust" wrote in message . nl... Peter HK wrote: "sherwindu" wrote in message ... One question nobody has addressed yet is what happens when a cat capsizes? There is no natural righting moment, as with a mono hull. I have never even sailed on a cat myself, but the heeling of a mono hull seems to offer some comfort advantages, because the combination of sails and pendulum keel act as a kind of 'shock absorber' in wavy conditions. I would prefer to be heeled over and on a steady lean than bounced up and down as one than another hull is lifted and dropped by a wave, especially in short choppy seas. Long rolling waves would probably somewhat nullify this advantage. I am referring more to waves on the beam, but there probably is some effect on a close hauled tack. Sherwin D. There are occasional sea patterns that are uncomfortable on a multi, usually with beam seas, but the magnitude of the event needs to be considered. Cats reach max stability at about 5 degrees of heel (when a hull lifts). As this never happens on cruising cats, all heel angles are less than 5 degrees. Short sharp waves can occasionally exceed this a little due to the hulls being in a trough and crest. Compare to a mono rolling downwind where heel angles can be 30 degrees side to side. Multis do have a different motion- shorter and sharper compared to slower but much more amplitude on a mono. Personally I find it quite comfortable. As stated in a previous post a glass never spills, which is a significant observation on the severity of the motion. When a multi capsizes it floats- most are now equipped with hatches to enter a secure part of the hull in a capsize. When a mono sinks however- dragged down by that ballast that makes it self-righting- the only hope is a liferaft. It depends on what you think is the most basic safety feature- nonsinkability or self righting. Peter HK I guess most people prefer to be upside-down-but-floating compared to upright-on-the-bottom of the Atlantic. The next question though, is what are chances of such events to happen? When I cross the Atlantic (or whatever waters) I rather opt for a 1% chance to sink my monohull (and trust on my liferaft) than a 20% chance of capsizing my cat. Now, both figures are probably far from accurate, so my question is, what are chances that such things will happen? Regards, Marc www.marineyacht.com I don't think I recall hearing about any cruising cats that have capsized. Where are you getting 20% or even 5%? I don't have a clue about those figures, that's why I said they (the figures) are probably far from accurate. I'm only trying to make clear (like discussed in the thread above as well) that you can only objectively compare the two events (sinking a monohull vs. capsizing a cat) if you know what the chances of both events are. In doing so, I over exaggerated both 1% and 20% figures, just to make my point clear. I would prefer a cat by the way. Cheers, Marc MarineYacht Yacht Charters |
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#10
posted to rec.boats.cruising
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"Marc Onrust" wrote in message
. nl... Capt. JG wrote: "Marc Onrust" wrote in message . nl... Peter HK wrote: "sherwindu" wrote in message ... One question nobody has addressed yet is what happens when a cat capsizes? There is no natural righting moment, as with a mono hull. I have never even sailed on a cat myself, but the heeling of a mono hull seems to offer some comfort advantages, because the combination of sails and pendulum keel act as a kind of 'shock absorber' in wavy conditions. I would prefer to be heeled over and on a steady lean than bounced up and down as one than another hull is lifted and dropped by a wave, especially in short choppy seas. Long rolling waves would probably somewhat nullify this advantage. I am referring more to waves on the beam, but there probably is some effect on a close hauled tack. Sherwin D. There are occasional sea patterns that are uncomfortable on a multi, usually with beam seas, but the magnitude of the event needs to be considered. Cats reach max stability at about 5 degrees of heel (when a hull lifts). As this never happens on cruising cats, all heel angles are less than 5 degrees. Short sharp waves can occasionally exceed this a little due to the hulls being in a trough and crest. Compare to a mono rolling downwind where heel angles can be 30 degrees side to side. Multis do have a different motion- shorter and sharper compared to slower but much more amplitude on a mono. Personally I find it quite comfortable. As stated in a previous post a glass never spills, which is a significant observation on the severity of the motion. When a multi capsizes it floats- most are now equipped with hatches to enter a secure part of the hull in a capsize. When a mono sinks however- dragged down by that ballast that makes it self-righting- the only hope is a liferaft. It depends on what you think is the most basic safety feature- nonsinkability or self righting. Peter HK I guess most people prefer to be upside-down-but-floating compared to upright-on-the-bottom of the Atlantic. The next question though, is what are chances of such events to happen? When I cross the Atlantic (or whatever waters) I rather opt for a 1% chance to sink my monohull (and trust on my liferaft) than a 20% chance of capsizing my cat. Now, both figures are probably far from accurate, so my question is, what are chances that such things will happen? Regards, Marc www.marineyacht.com I don't think I recall hearing about any cruising cats that have capsized. Where are you getting 20% or even 5%? I don't have a clue about those figures, that's why I said they (the figures) are probably far from accurate. I'm only trying to make clear (like discussed in the thread above as well) that you can only objectively compare the two events (sinking a monohull vs. capsizing a cat) if you know what the chances of both events are. In doing so, I over exaggerated both 1% and 20% figures, just to make my point clear. I would prefer a cat by the way. Cheers, Marc MarineYacht Yacht Charters I would also if I could afford it... :-) Actually, in the bay, I like the heel of the mono. I'm just not sure I want to do that again for days on end. -- "j" ganz @@ www.sailnow.com |
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