Capsize Prevention
Of course the first "prevention" is to avoid getting knocked down.
Now you don't have to say that. This discusses a inflated masthead bag for the F-27, and also examples of righting procedures for the F-27. The F-27 is a trimaran, which affords it huge advantages for righting. Maybe my favorite boat. Right up there with the Mac 26X/M, but for different reasons. http://www.f-boat.com/pages/backgrou...zearticle.html Monohulls can be so equipped too, but if hatches aren't sealed, most will just sink like a rock when knocked down unless equipped with positive buoyancy foam. Like the Mac 26M/X is. Sure, some owners have retro-fitted their boats with foam, but those aren't properly engineered and tank-tested. Amateur stuff and probably just more food for Davy Jones. But it's skiffs that got me thinking about this, because open boats are easily swamped, whereupon they are prone to rolling over Sure, a bit of hull sticks out of the water when the boat is constructed with positive buoyancy. Doesn't mean you can roll it back over, or that it's a good platform for survival. The NFL players lost off Tampa a while back are a good example. Four very strong men couldn't right that boat, which was well designed, and level floating when capsized. They tried. Had they been able to, they could have bailed and survived. So for typical open powerboats which might be subject to swamping and capsize, I'm thinking inflatable airbags on both gunnels.. Activation could be manual and/or automatic upon immersion. Keep that boat from rolling over when swamped. The engineering is straightforward and easily accomplished. The system would be lightweight and not affect boat performance. What's the problem? A number. 1. Cost. Might add a couple/few grand to the boat cost. 2. Cosmetics - some bulkiness or bumps on the gunnels. 3. Liability - if you sell it, it has to work - every time. Maybe there's disclaimers for that - I'm not a lawyer. 4. Safety ain't no fun. 5. But the biggest problem by far - I don't have my own boat manufacturing company. Somebody could market these systems to clamp onto the gunnels of any boat. Add some cupholders to ensure sales. Maybe an iPod option. Be creative. --Vic |
Capsize Prevention
On 10/17/09 6:27 PM, Vic Smith wrote:
Of course the first "prevention" is to avoid getting knocked down. Now you don't have to say that. This discusses a inflated masthead bag for the F-27, and also examples of righting procedures for the F-27. The F-27 is a trimaran, which affords it huge advantages for righting. Maybe my favorite boat. Right up there with the Mac 26X/M, but for different reasons. http://www.f-boat.com/pages/backgrou...zearticle.html Monohulls can be so equipped too, but if hatches aren't sealed, most will just sink like a rock when knocked down unless equipped with positive buoyancy foam. Like the Mac 26M/X is. Sure, some owners have retro-fitted their boats with foam, but those aren't properly engineered and tank-tested. Amateur stuff and probably just more food for Davy Jones. But it's skiffs that got me thinking about this, because open boats are easily swamped, whereupon they are prone to rolling over Sure, a bit of hull sticks out of the water when the boat is constructed with positive buoyancy. Doesn't mean you can roll it back over, or that it's a good platform for survival. The NFL players lost off Tampa a while back are a good example. Four very strong men couldn't right that boat, which was well designed, and level floating when capsized. They tried. Had they been able to, they could have bailed and survived. So for typical open powerboats which might be subject to swamping and capsize, I'm thinking inflatable airbags on both gunnels.. Activation could be manual and/or automatic upon immersion. Keep that boat from rolling over when swamped. The engineering is straightforward and easily accomplished. The system would be lightweight and not affect boat performance. What's the problem? A number. 1. Cost. Might add a couple/few grand to the boat cost. 2. Cosmetics - some bulkiness or bumps on the gunnels. 3. Liability - if you sell it, it has to work - every time. Maybe there's disclaimers for that - I'm not a lawyer. 4. Safety ain't no fun. 5. But the biggest problem by far - I don't have my own boat manufacturing company. Somebody could market these systems to clamp onto the gunnels of any boat. Add some cupholders to ensure sales. Maybe an iPod option. Be creative. --Vic How many times have you been aboard an open boat that swamped? In nearly 60 years of boating in small boats, I never have. -- http://tinyurl.com/ykaa4k7 |
Capsize Prevention
On Sat, 17 Oct 2009 18:45:10 -0400, H the K
wrote: How many times have you been aboard an open boat that swamped? In nearly 60 years of boating in small boats, I never have. Once, but I've done very little boating. Weather kicked up quick when fishing with my grand dad. Luckily, he was able to run it ashore and beach it, almost half full of water. It the engine had quit, who knows what would have happened. But boats swamp all the time. It's a leading cause of boat fatality mishaps. Pretty sure anyway. --Vic |
Capsize Prevention
On 10/17/09 6:52 PM, Vic Smith wrote:
On Sat, 17 Oct 2009 18:45:10 -0400, H the K wrote: How many times have you been aboard an open boat that swamped? In nearly 60 years of boating in small boats, I never have. Once, but I've done very little boating. Weather kicked up quick when fishing with my grand dad. Luckily, he was able to run it ashore and beach it, almost half full of water. It the engine had quit, who knows what would have happened. But boats swamp all the time. It's a leading cause of boat fatality mishaps. Pretty sure anyway. --Vic Well, on smaller round bottom boats, it's not that hard to be capsized. It's harder on 18' and larger wide flat-bottomed or vee or semi vee hulls, but, of course, it's not impossible. Plenty of guys go way out in the ocean with small boats, and have for centuries. I've done it on good days with weather reports and a constant eye on the horizon. On the Bay, which usually only has a constant chop or two-footers, the biggest problem seems to being run down by old farts in monster power cruisers, or hit by sailboaters during the high heat when their captains are semi-comatose. But that's mostly outside of Annapolis harbor. |
Capsize Prevention
On Sat, 17 Oct 2009 17:27:26 -0500, Vic Smith
wrote: Of course the first "prevention" is to avoid getting knocked down. Now you don't have to say that. This discusses a inflated masthead bag for the F-27, and also examples of righting procedures for the F-27. The F-27 is a trimaran, which affords it huge advantages for righting. Maybe my favorite boat. Right up there with the Mac 26X/M, but for different reasons. http://www.f-boat.com/pages/backgrou...zearticle.html Monohulls can be so equipped too, but if hatches aren't sealed, most will just sink like a rock when knocked down unless equipped with positive buoyancy foam. Like the Mac 26M/X is. Sure, some owners have retro-fitted their boats with foam, but those aren't properly engineered and tank-tested. Amateur stuff and probably just more food for Davy Jones. But it's skiffs that got me thinking about this, because open boats are easily swamped, whereupon they are prone to rolling over Sure, a bit of hull sticks out of the water when the boat is constructed with positive buoyancy. Doesn't mean you can roll it back over, or that it's a good platform for survival. The NFL players lost off Tampa a while back are a good example. Four very strong men couldn't right that boat, which was well designed, and level floating when capsized. They tried. Had they been able to, they could have bailed and survived. So for typical open powerboats which might be subject to swamping and capsize, I'm thinking inflatable airbags on both gunnels.. Activation could be manual and/or automatic upon immersion. Keep that boat from rolling over when swamped. The engineering is straightforward and easily accomplished. The system would be lightweight and not affect boat performance. What's the problem? A number. 1. Cost. Might add a couple/few grand to the boat cost. 2. Cosmetics - some bulkiness or bumps on the gunnels. 3. Liability - if you sell it, it has to work - every time. Maybe there's disclaimers for that - I'm not a lawyer. 4. Safety ain't no fun. 5. But the biggest problem by far - I don't have my own boat manufacturing company. Somebody could market these systems to clamp onto the gunnels of any boat. Add some cupholders to ensure sales. Maybe an iPod option. Be creative. --Vic A "knock down" is not necessarily a "capsize". In fact it seldom is and most sail boats will recover from a "knock down" with no action from the helmsman as at high angles of heel the rudder loses effect and normal sail action tends to turn the boat nose into the wind (on a properly rigged boat, that is :-) Cheers, Bruce (bruceinbangkokatgmaildotcom) |
Capsize Prevention
"Bruce In Bangkok" wrote in message
... On Sat, 17 Oct 2009 17:27:26 -0500, Vic Smith wrote: Of course the first "prevention" is to avoid getting knocked down. Now you don't have to say that. This discusses a inflated masthead bag for the F-27, and also examples of righting procedures for the F-27. The F-27 is a trimaran, which affords it huge advantages for righting. Maybe my favorite boat. Right up there with the Mac 26X/M, but for different reasons. http://www.f-boat.com/pages/backgrou...zearticle.html Monohulls can be so equipped too, but if hatches aren't sealed, most will just sink like a rock when knocked down unless equipped with positive buoyancy foam. Like the Mac 26M/X is. Sure, some owners have retro-fitted their boats with foam, but those aren't properly engineered and tank-tested. Amateur stuff and probably just more food for Davy Jones. But it's skiffs that got me thinking about this, because open boats are easily swamped, whereupon they are prone to rolling over Sure, a bit of hull sticks out of the water when the boat is constructed with positive buoyancy. Doesn't mean you can roll it back over, or that it's a good platform for survival. The NFL players lost off Tampa a while back are a good example. Four very strong men couldn't right that boat, which was well designed, and level floating when capsized. They tried. Had they been able to, they could have bailed and survived. So for typical open powerboats which might be subject to swamping and capsize, I'm thinking inflatable airbags on both gunnels.. Activation could be manual and/or automatic upon immersion. Keep that boat from rolling over when swamped. The engineering is straightforward and easily accomplished. The system would be lightweight and not affect boat performance. What's the problem? A number. 1. Cost. Might add a couple/few grand to the boat cost. 2. Cosmetics - some bulkiness or bumps on the gunnels. 3. Liability - if you sell it, it has to work - every time. Maybe there's disclaimers for that - I'm not a lawyer. 4. Safety ain't no fun. 5. But the biggest problem by far - I don't have my own boat manufacturing company. Somebody could market these systems to clamp onto the gunnels of any boat. Add some cupholders to ensure sales. Maybe an iPod option. Be creative. --Vic A "knock down" is not necessarily a "capsize". In fact it seldom is and most sail boats will recover from a "knock down" with no action from the helmsman as at high angles of heel the rudder loses effect and normal sail action tends to turn the boat nose into the wind (on a properly rigged boat, that is :-) Cheers, Bruce (bruceinbangkokatgmaildotcom) Sure thing... I've touched the main on the water many times years ago. The last time was probably 20 years ago on a Merit. -- "j" ganz @@ www.sailnow.com |
Capsize Prevention
"H K" wrote in message ... On 10/17/09 6:52 PM, Vic Smith wrote: On Sat, 17 Oct 2009 18:45:10 -0400, H the K wrote: How many times have you been aboard an open boat that swamped? In nearly 60 years of boating in small boats, I never have. Once, but I've done very little boating. Weather kicked up quick when fishing with my grand dad. Luckily, he was able to run it ashore and beach it, almost half full of water. It the engine had quit, who knows what would have happened. But boats swamp all the time. It's a leading cause of boat fatality mishaps. Pretty sure anyway. --Vic Well, on smaller round bottom boats, it's not that hard to be capsized. It's harder on 18' and larger wide flat-bottomed or vee or semi vee hulls, but, of course, it's not impossible. Plenty of guys go way out in the ocean with small boats, and have for centuries. I've done it on good days with weather reports and a constant eye on the horizon. On the Bay, which usually only has a constant chop or two-footers, the biggest problem seems to being run down by old farts in monster power cruisers, or hit by sailboaters during the high heat when their captains are semi-comatose. But that's mostly outside of Annapolis harbor. Small flat bottom boats flip all the time. Mostly Boston Whalers. They may not sink, but they need hand rails on the bottom. Which SOLAS lifeboats do have. |
Capsize Prevention
"Vic Smith" wrote in message ... Of course the first "prevention" is to avoid getting knocked down. Now you don't have to say that. This discusses a inflated masthead bag for the F-27, and also examples of righting procedures for the F-27. The F-27 is a trimaran, which affords it huge advantages for righting. Maybe my favorite boat. Right up there with the Mac 26X/M, but for different reasons. http://www.f-boat.com/pages/backgrou...zearticle.html Monohulls can be so equipped too, but if hatches aren't sealed, most will just sink like a rock when knocked down unless equipped with positive buoyancy foam. Like the Mac 26M/X is. Sure, some owners have retro-fitted their boats with foam, but those aren't properly engineered and tank-tested. Amateur stuff and probably just more food for Davy Jones. But it's skiffs that got me thinking about this, because open boats are easily swamped, whereupon they are prone to rolling over Sure, a bit of hull sticks out of the water when the boat is constructed with positive buoyancy. Doesn't mean you can roll it back over, or that it's a good platform for survival. The NFL players lost off Tampa a while back are a good example. Four very strong men couldn't right that boat, which was well designed, and level floating when capsized. They tried. Had they been able to, they could have bailed and survived. So for typical open powerboats which might be subject to swamping and capsize, I'm thinking inflatable airbags on both gunnels.. Activation could be manual and/or automatic upon immersion. Keep that boat from rolling over when swamped. The engineering is straightforward and easily accomplished. The system would be lightweight and not affect boat performance. What's the problem? A number. 1. Cost. Might add a couple/few grand to the boat cost. 2. Cosmetics - some bulkiness or bumps on the gunnels. 3. Liability - if you sell it, it has to work - every time. Maybe there's disclaimers for that - I'm not a lawyer. 4. Safety ain't no fun. 5. But the biggest problem by far - I don't have my own boat manufacturing company. Somebody could market these systems to clamp onto the gunnels of any boat. Add some cupholders to ensure sales. Maybe an iPod option. Be creative. --Vic Vic, if you put auto inflating bags on both gunwhales you will enure that you will never get her upright again but she will float nice and high while upside down. The Royal National Lifeboat Institution in Uk used to have boats that were inherently self righting but such a boat does tend to turn over more often than necessary which is a pain even if it rights itself afterwards. Modern lifeboats are not inherently self righting but instead have an automaically inflating buoyancy bag which is centrally mounted in the superstructure so it exerts maximum righting leverage whichever way she turns over. |
Capsize Prevention
On Sun, 18 Oct 2009 09:21:53 +0200, "Edgar"
wrote: Vic, if you put auto inflating bags on both gunwhales you will enure that you will never get her upright again but she will float nice and high while upside down. That seems counterintuitive. The gunnel bags would be inflated before the roll over. If the boat is already turtled or rolling past the ability of the bag buoyancy to right it when inflated, it would be as you say. That's a no-no. (-: But in case you're talking about heavy seas flipping a boat, you're absolutely right. Bags on the gunnels are worthless. I was thinking about the more common swamping situations. Anyway, without thorough testing and an understanding of the weight/buoyancy dynamics of a particular boat I wouldn't stand by any contraption I propose. The Royal National Lifeboat Institution in Uk used to have boats that were inherently self righting but such a boat does tend to turn over more often than necessary which is a pain even if it rights itself afterwards. Modern lifeboats are not inherently self righting but instead have an automaically inflating buoyancy bag which is centrally mounted in the superstructure so it exerts maximum righting leverage whichever way she turns over. That's similar to the masthead bags for sailboats. Then the problem becomes righting the boat from a laid down position. I was thinking that a good system for an open boat would prevent the capsize due to swamping, and leave only the bailing. No need to go outside the gunnels. But on that subject of righting, my recollection of righting small boats is that once one gunnel is free of the water, the rest of it goes pretty easy as that side lightens right up as water leaves it. Then the only issues left are not to let inertia roll it again on the other side, and getting it bailed out. The boats I righted always had me standing on the bottom, so muscles can be well-used. Totally different than doing it while afloat, which from what I've seen is darn near impossible without motor power, unless it's a very light weight boat, even with a crew of strong men. If I were in the business of righting small boats, I'd carry a rig to make an A-frame over a capsized hull to get some leverage. Maybe 10-12 foot scaffolding type tubes. One side has a hook to go over the offside gunnel, one side a clamp for the nearside gunnel on a u-joint. Both are joined at the apex, where a line is attached. Should make it a lot easier to roll the boat back over pulling on the nearside, whether with a power boat or men in the water. Man, I wish I lived by that warm Florida water where I could monkey around with this stuff. That would be fun. If the fishing is slow, go play with turtled boats. --Vic |
Capsize Prevention
Vic Smith wrote:
On Sat, 17 Oct 2009 18:45:10 -0400, H the K wrote: How many times have you been aboard an open boat that swamped? In nearly 60 years of boating in small boats, I never have. Once, but I've done very little boating. Weather kicked up quick when fishing with my grand dad. Luckily, he was able to run it ashore and beach it, almost half full of water. It the engine had quit, who knows what would have happened. But boats swamp all the time. It's a leading cause of boat fatality mishaps. Pretty sure anyway. --Vic Top causes of accidents: Number of Accidents/Number of Deaths/Number of Injuries 1 Collision with Vessel 1237 60 856 2 Flooding/swamping 475 89 179 3 Collision with Fixed Object 446 53 328 4 Falls Overboard 431 188 257 5 Skier Mishap 383 10 397 However, when we look at "all accident types" we find that capsizes actually have more deaths from a smaller number of (reported) accidents: Accidents/Vessels Involved/Drowning/Other Deaths/Total Deaths All Accident Types 4789 6347 510 199 709 Capsizing 348 359 163 26 189 Carbon Monoxide Exposure 18 19 0 11 11 Collision with Fixed Object 446 501 23 30 53 Collision with Floating Object 59 64 4 1 5 Collision with Vessel 1237 2547 11 49 60 Departed Vessel 87 106 37 0 37 Ejected from Vessel 123 135 11 6 17 Electrocution 0 0 0 0 0 Fall in Vessel 140 147 1 1 2 Fall on Vessel 62 66 0 1 1 Falls Overboard 431 447 157 31 188 Fire/Explosion (fuel) 136 29 0 1 1 Fire/Explosion (non-fuel) 78 164 1 1 2 Fire/Explosion (Unknown origin) 25 84 2 0 2 Flooding/Swamping 475 497 80 9 89 Grounding 322 330 3 10 13 Sinking 16 16 0 2 2 Skier Mishap 383 398 6 4 10 Struck by Vessel 37 51 0 2 2 Struck by Propeller 83 86 0 5 5 Struck Submerged Object 154 154 4 1 5 Other 123 141 4 5 9 Unknown 6 6 3 3 6 So adding all deaths from capsize and Flooding/Swamping we have 278, or 39% of the total of 709. Looking further, of the 359 capsizes, only 5 were by Aux Sail and 22 by Sail only. Also, of the total 709 deaths, 15 were Aux sail, 10 were other sail. One odd item jumped out: of the 15 deaths in Aux Sail, 8 were age 60-69. I guess I should be writing a will. I looked at 2007 to see if this was an anomaly, and then, 4 out of 18 were 60-69. However, leaving out the "unknown age," 10 out of 14 were 50 or older. BTW, Aux Sailboat make up a bit over 1% of the boats with power, so the 15 deaths are more than their share, but its still a small enough number that people will think the are relatively safe. Since most un-powered boats are not registered, its not easy to determine their relative safety. We'd have to look at hours spent in various types of boats, etc. from: http://www.uscgboating.org/assets/1/...stics_2008.pdf |
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