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#1
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I just finished reading all 57 posts of a msg. which appeared in
February having to do with "whether or not a 45-ft. boat could survive "severe" weather or something to that effect. I was both informed and entertained by that thread--informed because there were some excellent analyses which were enlightening to me and entertained by the quality of the flames going back and forth. This might provoke another flame war but I (and others) might learn something in the process so here goes: There is a discussion going on in a list-serve group I subscribe to as to the benefit of adding bouyancy to the top of the mast through an inflatable device which would automatically deploy were the mast to become submerged in a roll over. I am fascinated by the concept and would love to have the input from some of the excellent minds iin this newsgroup who post on such matters.. Currently there is no such device being marked (but think of the commericial potential--Waste Marine could make megabucks by having them manufactured in Taiwan for $25.00 and selling them to their victims (excuse me--customers) for $2500.00. Some posters suggested something as simple as running an automatic PFD up to the top of the mast on a halyard when conditions warranted. Others suggested canister-type inflatable devices permanently mounted. Some claimed such a device would cause the mast to break. Others claim the devices would right the boat forthwith. There are elaborate calculations "proving" that the 40 or so pounds of bouyancy offered by the PFD would equal thousands of pounds in righting force. And . . . for the final word from our panel of experts. |
#2
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Joe Bleau wrote:
I just finished reading all 57 posts of a msg. which appeared in February having to do with "whether or not a 45-ft. boat could survive "severe" weather or something to that effect. I was both informed and entertained by that thread--informed because there were some excellent analyses which were enlightening to me and entertained by the quality of the flames going back and forth. This might provoke another flame war but I (and others) might learn something in the process so here goes: There is a discussion going on in a list-serve group I subscribe to as to the benefit of adding bouyancy to the top of the mast through an inflatable device which would automatically deploy were the mast to become submerged in a roll over. I am fascinated by the concept and would love to have the input from some of the excellent minds iin this newsgroup who post on such matters.. Currently there is no such device being marked (but think of the commericial potential--Waste Marine could make megabucks by having them manufactured in Taiwan for $25.00 and selling them to their victims (excuse me--customers) for $2500.00. Some posters suggested something as simple as running an automatic PFD up to the top of the mast on a halyard when conditions warranted. Others suggested canister-type inflatable devices permanently mounted. Some claimed such a device would cause the mast to break. Others claim the devices would right the boat forthwith. There are elaborate calculations "proving" that the 40 or so pounds of bouyancy offered by the PFD would equal thousands of pounds in righting force. And . . . for the final word from our panel of experts. Dunno about a 45 foot boat, but flotation is common at the top of small catamarans |
#3
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Many flaws on this idea from what I can see.
1) The chances of rolling over are very slim, you would need to be in very heavy weather but in any case if it does happen your boat with roll itself back up by itself due to the keel. In the case that for some reason your boat does looses its keel, there is very little the mast will do other than keep the boat sideways and not upside down(it might even make you sink faster). 2) You already have all kinds of things in your mast. Generally these are wires, tubes, bolts and many other things indented into it. The moment you inflate something in there its prolly going to pop besides just being a pain getting in the way of everything. In any case, a roll is generally so fast that I dont think much water would get into the mast so it would have similar effect anyways. 3)Theres a pretty big chance that if you do get rolled over that you will have sails up, and the increased load from the wave will snap some part of your rigging and your mast will break like a toothpic in up to 3 places(ie. if it just comes down from an upright boat it will snap on the lifelines and then on where it hits the water). It would be useless in this case and will prolly blow up since it has no where to expand to. "Joe Bleau" wrote in message ... I just finished reading all 57 posts of a msg. which appeared in February having to do with "whether or not a 45-ft. boat could survive "severe" weather or something to that effect. I was both informed and entertained by that thread--informed because there were some excellent analyses which were enlightening to me and entertained by the quality of the flames going back and forth. This might provoke another flame war but I (and others) might learn something in the process so here goes: There is a discussion going on in a list-serve group I subscribe to as to the benefit of adding bouyancy to the top of the mast through an inflatable device which would automatically deploy were the mast to become submerged in a roll over. I am fascinated by the concept and would love to have the input from some of the excellent minds iin this newsgroup who post on such matters.. Currently there is no such device being marked (but think of the commericial potential--Waste Marine could make megabucks by having them manufactured in Taiwan for $25.00 and selling them to their victims (excuse me--customers) for $2500.00. Some posters suggested something as simple as running an automatic PFD up to the top of the mast on a halyard when conditions warranted. Others suggested canister-type inflatable devices permanently mounted. Some claimed such a device would cause the mast to break. Others claim the devices would right the boat forthwith. There are elaborate calculations "proving" that the 40 or so pounds of bouyancy offered by the PFD would equal thousands of pounds in righting force. And . . . for the final word from our panel of experts. |
#4
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![]() "Sebastian Miles" wrote in message ... Many flaws on this idea from what I can see. 1) The chances of rolling over are very slim, you would need to be in very heavy weather but in any case if it does happen your boat with roll itself back up by itself due to the keel. In the case that for some reason your boat does looses its keel, there is very little the mast will do other than keep the boat sideways and not upside down(it might even make you sink faster). 2) You already have all kinds of things in your mast. Generally these are wires, tubes, bolts and many other things indented into it. The moment you inflate something in there its prolly going to pop besides just being a pain getting in the way of everything. In any case, a roll is generally so fast that I dont think much water would get into the mast so it would have similar effect anyways. 3)Theres a pretty big chance that if you do get rolled over that you will have sails up, and the increased load from the wave will snap some part of your rigging and your mast will break like a toothpic in up to 3 places(ie. if it just comes down from an upright boat it will snap on the lifelines and then on where it hits the water). It would be useless in this case and will prolly blow up since it has no where to expand to. "Joe Bleau" wrote in message ... I just finished reading all 57 posts of a msg. which appeared in February having to do with "whether or not a 45-ft. boat could survive "severe" weather or something to that effect. I was both informed and entertained by that thread--informed because there were some excellent analyses which were enlightening to me and entertained by the quality of the flames going back and forth. This might provoke another flame war but I (and others) might learn something in the process so here goes: There is a discussion going on in a list-serve group I subscribe to as to the benefit of adding bouyancy to the top of the mast through an inflatable device which would automatically deploy were the mast to become submerged in a roll over. I am fascinated by the concept and would love to have the input from some of the excellent minds iin this newsgroup who post on such matters.. Currently there is no such device being marked (but think of the commericial potential--Waste Marine could make megabucks by having them manufactured in Taiwan for $25.00 and selling them to their victims (excuse me--customers) for $2500.00. Some posters suggested something as simple as running an automatic PFD up to the top of the mast on a halyard when conditions warranted. Others suggested canister-type inflatable devices permanently mounted. Some claimed such a device would cause the mast to break. Others claim the devices would right the boat forthwith. There are elaborate calculations "proving" that the 40 or so pounds of bouyancy offered by the PFD would equal thousands of pounds in righting force. And . . . for the final word from our panel of experts. I'd rather see a line from the top of the mast rigged with pull away support attached to a rocket that has an expandable sea anchor that the boat owner could launch outboard and then reel in to right the boat. This could double as a life line to launch at overboard sailors. The line could be attached (before being rigged to the top of the mast) to the side of the boat using a seatbelt type latch that would only release if the boat were on it's side. A further latch would release the line from the mast when the mast was again perpendicular. |
#5
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Joe Bleau wrote:
I just finished reading all 57 posts of a msg. which appeared in February having to do with "whether or not a 45-ft. boat could survive "severe" weather or something to that effect. I was both informed and entertained by that thread--informed because there were some excellent analyses which were enlightening to me and entertained by the quality of the flames going back and forth. This might provoke another flame war but I (and others) might learn something in the process so here goes: There is a discussion going on in a list-serve group I subscribe to as to the benefit of adding bouyancy to the top of the mast through an inflatable device which would automatically deploy were the mast to become submerged in a roll over. I am fascinated by the concept and would love to have the input from some of the excellent minds iin this newsgroup who post on such matters.. Currently there is no such device being marked (but think of the commericial potential--Waste Marine could make megabucks by having them manufactured in Taiwan for $25.00 and selling them to their victims (excuse me--customers) for $2500.00. Some posters suggested something as simple as running an automatic PFD up to the top of the mast on a halyard when conditions warranted. Others suggested canister-type inflatable devices permanently mounted. Some claimed such a device would cause the mast to break. Others claim the devices would right the boat forthwith. There are elaborate calculations "proving" that the 40 or so pounds of bouyancy offered by the PFD would equal thousands of pounds in righting force. And . . . for the final word from our panel of experts. Don't believe you're the first to think of this! Usually the rig is not strong enough to survive being rolled. Most boats that roll are dismasted. Floatation at the very end of the mast will only increase the load on the rig, causing the mast to break sooner. Then there's the extra weight and windage of this equipment at the top of the mast, which reduces stability the rest of the time. A better way to approach this problem is to seal the mast itself, running halyards, etc., externally. Many boats have this feature. It doesn't add significant weight or windage, and the load is more evenly distributed (vs. all at the top). Also, since the rig is designed with this in mind from the beginning, it can be made stronger to compensate, unlike the retrofit mentioned above. Matt O. |
#6
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On Wed, 20 Apr 2005 14:25:05 -0400, "Matt O'Toole"
wrote: A better way to approach this problem is to seal the mast itself, running halyards, etc., externally. ============================================= External halyards are a really bad idea. They are easier to maintain but the extra clutter and windage is a huge negative. As others have pointed out, if a keel boat rolls, it will almost always lose the rig and come back upright regardless (unless it fills and sinks). Flotation at the mast top is good for one thing on small boats: It prevents turning turtle and achieving stability mode #2, or inverting the mast into the mud. |
#7
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Wayne.B wrote:
On Wed, 20 Apr 2005 14:25:05 -0400, "Matt O'Toole" wrote: A better way to approach this problem is to seal the mast itself, running halyards, etc., externally. ============================================= External halyards are a really bad idea. They are easier to maintain but the extra clutter and windage is a huge negative. They said the same thing 40 years ago about internal halyards. Now some state of the art designers are saying it again. Calling the windage and clutter penalty "huge" is overstating it a bit, I think. Matt O. |
#8
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On Thu, 21 Apr 2005 01:52:23 -0400, "Matt O'Toole"
wrote: Wayne.B wrote: On Wed, 20 Apr 2005 14:25:05 -0400, "Matt O'Toole" wrote: A better way to approach this problem is to seal the mast itself, running halyards, etc., externally. ============================================= External halyards are a really bad idea. They are easier to maintain but the extra clutter and windage is a huge negative. They said the same thing 40 years ago about internal halyards. Now some state of the art designers are saying it again. Calling the windage and clutter penalty "huge" is overstating it a bit, I think. We have a 24-year old boat with four internal halyards and an internal ple lift. Never had a bit of trouble in that length of time. Any penalty for external is too much. And there is plenty of penalty to be had. Rodney Myrvaagnes NYC J36 Gjo/a "Curse thee, thou quadrant. No longer will I guide my earthly way by thee." Capt. Ahab |
#9
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Rodney Myrvaagnes wrote:
On Thu, 21 Apr 2005 01:52:23 -0400, "Matt O'Toole" wrote: Wayne.B wrote: On Wed, 20 Apr 2005 14:25:05 -0400, "Matt O'Toole" wrote: A better way to approach this problem is to seal the mast itself, running halyards, etc., externally. ============================================= External halyards are a really bad idea. They are easier to maintain but the extra clutter and windage is a huge negative. They said the same thing 40 years ago about internal halyards. Now some state of the art designers are saying it again. Calling the windage and clutter penalty "huge" is overstating it a bit, I think. We have a 24-year old boat with four internal halyards and an internal ple lift. Never had a bit of trouble in that length of time. Any penalty for external is too much. And there is plenty of penalty to be had. Rodney Myrvaagnes NYC J36 Gjo/a Ever notice the helical stairways on the outsides at the tops of tall smokestacks? They are not stairs. They generate vortices that reduce aerodynamic drag on flimsy chimneys in the wind. Vortex generators on the leading edges of moths' wings generate vortex "membranes", bubbles that make their flat wings aerodynamically more efficient with the vortex air acting like a curved wing's top skin. An external halyard can be bungied away from a mast, or wrapped half around it snug, but cannot be stopped from slapping around if inside. The rythmic music of a gentle anchorage's lapping wavelets and gently gonging halyards can serve as a counterpoise to the feared racket of a rising wind's hammering shriek and slap, awakening the sailor who's crew is absent to check his anchor. There is no such thing as perfect silence, as the pounding of the blood will arouse an unrested sleeper with worry in his head. Nothing will stop a faithful soul from finding peaceful repose even in a cement mixer rolling downhill. We can control our own oblivion. Accept it or avoid it, we do it all through reason. Still, some golfers get the yips. Terry K |
#10
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On Thu, 21 Apr 2005 01:52:23 -0400, "Matt O'Toole"
wrote: Calling the windage and clutter penalty "huge" is overstating it a bit, I think. ============ Depends on how you use the boat. If you are at all interested in performance and sail handling, external halyards are a big negative. They disrupt the airflow around the mast and are forever becoming crossed with other halyards at inopportune times, particularly at night. They also make it more difficult to prevent halyard clatter at anchor or dockside. |
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