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Inherently beautiful.
Depends on whether it it a right or left hand screw of course.
Cheers MC Simple Simon wrote: Walking and rudder power are intmately related. Walking is more a natural function of how a propeller works that has to be counteracted by a rudder to keep it from having its way. For example, you are aboard a right-handed single screw vessel with headway on. The engine is put full astern and the rudder hard left. The bow will first swing to the left and the swing to the right as the vessel loses way. The swing of the bow to the left is a function of rudder control while the swing to the right as the vessel loses way is caused by the prop walk overcoming the effects of the rudder because of the decreased speed and decreased rudder control. I hope this helps. S.Simon. "otnmbrd" wrote in message k.net... DSK wrote: In harbors the world over. I mean everywhere, We all know where they put Multi-Hulls. on the very end slips of finger piers or bouyed mooring. The Captains Nemesis wrote: Interesting. Here the cats tend to be deep into the marinas (other than casuals) because they have the ability to turn in there own length under power No doubt that cats under power with wide spaced twin engines are very maneuverable under power. Let's face facts; a Multi trying to manouver ( Over even making a simple turn in tight quarters) is not a pretty thing. Even under power. Skilled hands make light work under power. Juggling thrust can walk a cat sideways and maneuver in ways that monos can only dream. I'd like to see that. Theory suggests that with small props & rudders, prop walk and kick aren't going to move it sideways much. In practice?? Interesting .... I'd have thought the opposite. Since "walking" is highly dependent on rudder power and most sailboats tend to have better than average power in this area and a "cat" doesn't tend to have a great deal of wetted area and or windage (exceptions noted), I'd have guess them to be good candidates for "walking". otn |
Inherently beautiful.
Pages written by lubbers! Fancy not saying what hand the screws are!
Cheers MC Jeff Morris wrote: 2GM20FC with SD20 Saildrive, bottom of page: http://www.yanmar.com.au/marine/Sail...sailseries.htm Also, the props are shown on this page - search for 872880 http://www.penta.volvo.se/files/kapitel45-gb.pdf "Simple Simon" wrote in message ... Hey silly, Yanmars turn clockwise looking at them from the stern. Unless you have a weird, v-drive tranny or something your props turn clockwise. S.Simon "Jeff Morris" jeffmo@NoSpam-sv-lokiDOTcom wrote in message ... Both turn the same way, Counterclockwise, when viewed from the stern. I think. I actually had a prop in my hand this afternoon to bring home, and decided that was silly! But I do know for sure they both go the same way! "otnmbrd" wrote in message thlink.net... G May be wrong answer .... when looking from astern, both props turn clockwise, when engines ahead? or does stbd turn one way and port, the other? (may be part of the reason for no walk). otn Jeff Morris wrote: Yes. There're not counter-rotating. As to what happens when I try to "walk" - I can't quite remember exactly - she just jiggles forward or back but never really gets and loser to the dock! Of course, I wish we had this discussion yesterday, I could have tried it out this morning! But as they say here in Boston, "Wait till next season!" "otnmbrd" wrote in message rthlink.net... Dang it! That's twice I forgot to ask .....inboard or outboard turning props? otnmbrd wrote: Walk set-up is correct (props control bow, rudders control stern). Don't think your keel (from what I saw in the picture) is the problem. Seemingly (but not) unimportant question .... which end lags behind .... bow or stern? (in your example, hard right rudder, engines clutched, only,[no throttle] for left twist) BTW, I'm hoping you say bow, lags behind G. otn Jeff Morris wrote: Oy! You had to ask! It isn't easy to remember with the controls in front of me, but I guess: To walk to Port, Rudders to Starboard, Port Engine in Reverse, Starboard Engine Forward. The works with many twin screw boats, but I think mine has a keel that too long - I wonder if its too efficient at low speed? Also, although the rudders are large, they are hung on skegs and set back a bit from the screws, which are folding. I think all these things add up to minimal "walking." -jeff "otnmbrd" wrote in message .earthlink.net... G It varies a lot with all multi screw (except tractor tugs). From the look at the picture, I would think she'd "walk" fairly well ( I'm talking about sideways motion, not prop walk). Just out of curiosity, when you set up to "walk" to stbd, how do you set your engines and rudders? .... and which part has the problem keeping up, bow or stern? otn Jeff Morris wrote: And the answer is: It varies a lot with the cat. Some have long keels, others have daggerboards. Some have steerable drives, some have a single outboard, some have a widely spaced diesels. Some have little windage, others a lot. My boat has long keels, low windage on the bow (more aft), and widely space diesels. She can pivot in place very nicely but has little prop walk. People have told me they could make it go sideways, but when I've challenged them to try, they've always failed. I often have to dock on a face, which is actually often tough - I usually rely on getting close enough to snag a cleat, then springing in the rest of the way. If I have a few hands around to help I can usually get the boat anywhere I want. The hands don't have to do much of anything, but I find it difficult to singlehand because the visibility around the edges is limited. This morning I had a special challenge - I had to back into a TravelLift the is about 6 inches wider than my beam. The wind started light, but picked up to about 15 knots cross as I was coming in. The real problem was that one prop had trouble staying open in foreword - I had to do most of the work with just one engine. This made it difficult to stay lined up. I felt that I totally turkeyed it, but I was complimented by the Lift- Meister and dockhand, and no damage was done. I found that the gearing that forces to two blades to open together had totally sheared off. Here's a pic taken slightly later: http://www.sv-loki.com/Img_1616a.jpg |
Inherently beautiful.
Depends on whether it it a right or left hand screw of cours
Neal rarely gets either. RB |
Inherently beautiful.
I'm just the opposite - I can't bear the thought of having it done without being there. I feel the same way but I cringe through the whole process....ever seen = one dropped? It ain't pretty.... --=20 katysails s/v Chanteuse Kirie Elite 32 http://katysails.tripod.com "Women and cats will do as they please, and men and dogs should relax and get used to the idea." - Robert A. Heinlein |
Inherently beautiful.
Subject: Inherently beautiful.
From: =?ISO-8859-1?Q?The=5Fnavigator=A9?= Date: 10/21/2003 13:07 Pacific Standard Time Message-id: Depends on whether it it a right or left hand screw of course. Cheers MC Simple Simon wrote: Walking and rudder power are intmately related. The discussion in question, was way over Neal's head and/or experience. Shen |
Inherently beautiful.
Why do you say that? Why did you decline to respond
to my post about the affects of rudder vs. prop walk in the situation I described? Was it because you failed to understand what was said? S.Simon "Shen44" wrote in message ... The discussion in question, was way over Neal's head and/or experience. Shen |
Inherently beautiful.
Subject: Inherently beautiful.
From: "Simple Simon" Date: 10/22/2003 05:36 Pacific Standard Time Message-id: Why do you say that? Why did you decline to respond to my post about the affects of rudder vs. prop walk in the situation I described? Was it because you failed to understand what was said? S.Simon This post, and the one, from you, which brought about my response, highlights the reason for my response. They were not talking about single screw "prop walk". They were talking about making, or the possibilities of making, a twin screw boat "walk" sideways. Your post was a dissertation on a basic "motorboat" maneuver, with a fixed pitch, right hand propellor. (possible exceptions noted) The fact you weren't aware of this and made your post, showed that the topic was "over your head and/or beyond your experience". Shen |
Inherently beautiful.
Duh! Two fixed props spinning in the same direction
as on Jeff's catamaran will act the same was as one fixed prop on a monohull. You sure you're a licensed captain. You just aren't too bright. S.Simon "Shen44" wrote in message ... Subject: Inherently beautiful. From: "Simple Simon" Date: 10/22/2003 05:36 Pacific Standard Time Message-id: Why do you say that? Why did you decline to respond to my post about the affects of rudder vs. prop walk in the situation I described? Was it because you failed to understand what was said? S.Simon This post, and the one, from you, which brought about my response, highlights the reason for my response. They were not talking about single screw "prop walk". They were talking about making, or the possibilities of making, a twin screw boat "walk" sideways. Your post was a dissertation on a basic "motorboat" maneuver, with a fixed pitch, right hand propellor. (possible exceptions noted) The fact you weren't aware of this and made your post, showed that the topic was "over your head and/or beyond your experience". Shen |
Inherently beautiful.
Subject: Inherently beautiful.
From: "Simple Simon" Date: 10/22/2003 10:07 Pacific Standard Time Message-id: Duh! Two fixed props spinning in the same direction as on Jeff's catamaran will act the same was as one fixed prop on a monohull. You sure you're a licensed captain. You just aren't too bright. S.Simon ROFLMAO DUH!!! You STILL don't understand what was being discussed ..... as stated twice before WAY over your head and experience!! Shen |
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