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how necessary is a windlass
Jessica B wrote:
At first someone claimed that the waterline difference would be tiny. I found to be what seems a recent photo where that's not the case, and now you're claiming it's a relic? I don't get that. Either it can be a factor or it can't be. If I may again... Compare a Catalina 27 and My Catalina 26. My waterline is 3 inches longer. That's because the 27 has significant overhangs on both ends. Overhangs are the part of the hull above the waterline forward or aft of the waterline/hull point. If there is a lot of hull forward of where the water meets the hull then you have a long bow overhang. Same for the stern. Heeled 30 degrees (quite a bit actually) the 27's waterline length just about matches my 26's. Any less heel and the 27 is shorter than the 26. Waterline length that is... So, what does it mean as far as speed goes? Three inches is 1/4 of a foot. So.. 1.33 * sqrt (.25) = ? 1.33 * .5 = .665 knots difference In theory, at least. Which can be easily hidden by sail trim, rudder position, sea state, etc Yes, I get that current is only a real help in a few instances. What about the gulf stream example? I don't think that changes direction does it? Current is not tide. Tides change direction. Currents usually do not. -- Richard Lamb |
how necessary is a windlass
Jessica B wrote:
Sorry, but I just don't understand the logic. Sorry, I was trying to explain why it is illogical to attempt to outrun weather patterns in a vehicle that thunders through the waves at 5 miles an hour - A kid on a Huffy can outrun you. Sheehs, a fast walker can "outrun" you. Cheers, Bruce (bruceinbangkokatgmaildotcom) I didn't say out run anything. I thought we were talking about the difference between 5mph and 7mph over a distance. That's a significant time difference over a longish distance. Not really. It's not a different of days, at least. 200 nm at 5 knots = 100 hours 200 nm at 7 knots = 71 hours And if running from a storm you are running into a lee shore and shallow water - just before the storm hits? Pass... -- Richard Lamb email me: web site: http://www.home.earthlink.net/~cavelamb |
how necessary is a windlass
CaveLamb wrote:
Jessica B wrote: Sorry, but I just don't understand the logic. Sorry, I was trying to explain why it is illogical to attempt to outrun weather patterns in a vehicle that thunders through the waves at 5 miles an hour - A kid on a Huffy can outrun you. Sheehs, a fast walker can "outrun" you. Cheers, Bruce (bruceinbangkokatgmaildotcom) I didn't say out run anything. I thought we were talking about the difference between 5mph and 7mph over a distance. That's a significant time difference over a longish distance. Not really. It's not a different of days, at least. 200 nm at 5 knots = 100 hours 200 nm at 7 knots = 71 hours And if running from a storm you are running into a lee shore and shallow water - just before the storm hits? Pass... Sorry Jessica That was supposed to be 500 miles -- Richard Lamb email me: web site: http://www.home.earthlink.net/~cavelamb |
how necessary is a windlass
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how necessary is a windlass
On Mon, 28 Mar 2011 22:16:58 -0500, CaveLamb
wrote: Three inches is 1/4 of a foot. So.. 1.33 * sqrt (.25) = ? 1.33 * .5 = .665 knots difference In theory, at least. 27^.5=5.2 27.25^.5=5.22. Three hundredths of a knot difference. Casady |
how necessary is a windlass
On Tue, 29 Mar 2011 05:04:01 -0500, Richard Casady
wrote: On Mon, 28 Mar 2011 22:16:58 -0500, CaveLamb wrote: Three inches is 1/4 of a foot. So.. 1.33 * sqrt (.25) = ? 1.33 * .5 = .665 knots difference In theory, at least. 27^.5=5.2 27.25^.5=5.22. Three hundredths of a knot difference. Casady Hmmm. HP calculator? --Vic |
how necessary is a windlass
Vic Smith wrote:
On Tue, 29 Mar 2011 05:04:01 -0500, Richard Casady wrote: On Mon, 28 Mar 2011 22:16:58 -0500, CaveLamb wrote: Three inches is 1/4 of a foot. So.. 1.33 * sqrt (.25) = ? 1.33 * .5 = .665 knots difference In theory, at least. 27^.5=5.2 27.25^.5=5.22. Three hundredths of a knot difference. Casady Hmmm. HP calculator? --Vic Sorry guys :) Just late and not paying attention to the numbers. Half a knot for 3 inches does seem a little funny, doesn't it... -- Richard Lamb email me: web site: http://www.home.earthlink.net/~cavelamb |
how necessary is a windlass
"Jessica B" wrote in message
... On Thu, 24 Mar 2011 05:39:14 +0700, Bruce in Bangkok wrote: On Mon, 21 Mar 2011 20:35:30 -0500, CaveLamb wrote: Jessica B wrote: Hmmm... well, I looked up theoretical boat speed... 1.34 x the root of LWL. But, I read that when the boat leans (heels) then the LWL would get longer, so the theoretical speed would go up right? Also, what about the water moving. If it's going in the same direction, then that would decrease the time you spend traveling. But how MUCH longer does the waterline get? Seldom more than a few inches at most. As for the other, it's called current. And if you are going against it, slower than the current is running, you go backwards... What fun, huh? The long overhangs was a relic of one of the old racing rules that penalized long waterlines. So, the crafty people built a boat with a very short waterline and sailed it heeled and had a effective waterline much longer then what was measured for handy cap rating. Current is only a real help in the few instances where it always runs the same way. The more usual conditions have it going one way for a half a day and the other way for the other half. Net help = Zero. Cheers, Bruce (bruceinbangkokatgmaildotcom) At first someone claimed that the waterline difference would be tiny. I found to be what seems a recent photo where that's not the case, and now you're claiming it's a relic? I don't get that. Either it can be a factor or it can't be. Yes, I get that current is only a real help in a few instances. What about the gulf stream example? I don't think that changes direction does it? The Gulf Stream proper always sets the same direction. The only thing that can and does change is the loop currents which are eddies off the sides that gyre around and can even set in the opposite direction of that in the axis of the Stream. Bruce is often confused. He's even confused about the tides in my part of the world and probably in his part of the world as well. There are two high tides and two low tides a day here. That means in areas where there is a tidal flow the current switches approximately every six hours - not twice a day as Bruce said. Furthermore, his conclusion about net help = zero is also flawed for a couple of reason. 1) off soundings (in deep water) there are no tidal currents as they are a shallow water phenomena. 2) an experienced sailor departs and arrives 'on the tide' which means with a favorable tidal current (astern) so there can be significant gains especially in real parts of the sailing world where there are diurnal tides (two highs and two lows a day). Bruce is talking about semi-diurnal tides. He thinks pretty much like your typical lubber, I'm afraid. Bruce is also misinformed about the great ocean currents (of which the Gulf Stream is a notable example) most of which always set in the same direction day in and day out, year in and year out. The changing tides don't affect these currents or affect them very little; they most certainly don't affect the direction of flow. Your instincts are good, Jessica B. Don't let Bruce pull the wool over your eyes. Wilbur Hubbard |
how necessary is a windlass
"Jessica B" wrote in message
... On Thu, 24 Mar 2011 05:39:13 +0700, Bruce in Bangkok wrote: On Mon, 21 Mar 2011 16:44:36 -0700, Jessica B wrote: On Thu, 17 Mar 2011 06:55:15 +0700, Bruce in Bangkok wrote: On Wed, 16 Mar 2011 16:02:48 -0700, Jessica B wrote: Much Bumph snipped Ok... so if you have boat that'll go 10 mph and the reverse tide is pulling you at 5 mph vs. you have a boat that'll only go 5 mph.... You are still looking at speeds in excess of what the "normal" cruising boat is capable of sustaining for any cruise. Cheers, Bruce (bruceinbangkokatgmaildotcom) I can't imagine that having a good boat and proceeding at as fast as possible to avoid bad weather would somehow be more dangerous. Sorry, but I just don't understand the logic. Sorry, I was trying to explain why it is illogical to attempt to outrun weather patterns in a vehicle that thunders through the waves at 5 miles an hour - A kid on a Huffy can outrun you. Sheehs, a fast walker can "outrun" you. Cheers, Bruce (bruceinbangkokatgmaildotcom) I didn't say out run anything. I thought we were talking about the difference between 5mph and 7mph over a distance. That's a significant time difference over a longish distance. You go, girl! Right again, Jessica B. You definitely have the potential to make a fine first mate. Bruce can be such a trouble-maker. Always with the obfuscation and confusion because he refuses to admit when he lost because he's up against his betters. Again, you are totally correct about even a 2mph speed differential. It amounts to a lot of extra distance covered on an ocean voyage or even a coastal cruise and can make a real difference, like in my part of the world where much of the year some pretty severe thunderstorms can pop up in the late afternoons. I'd sure rather be hunkered down in a snug harbor because my boat was a couple knots faster than the next guy's when the thunder and lighting and gust fronts roll through than still struggling to fetch the inlet. I'm talking gusts up to 40 or 50 knots in some of the roll clouds. And, lots of heavy lightning strikes. You can't sail in that kinda stuff. You just have to take down and secure all sails and heave-to until it passes. And lightning often likes to strike the one lone boat silly enough to still be in harm's way with a nice metal mast sticking up into the sky to act like a lightning rod. Wilbur Hubbard |
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