dak Posted February 3, 2008 #26 Share Posted February 3, 2008 Isn't it called a sponson? David Link to comment Share on other sites More sharing options...
PRINSENDAM Posted February 3, 2008 #27 Share Posted February 3, 2008 Isn't it called a sponson? David David, yes it is. But sponsons can also run along the length of the ship. I'm sure you have seen some images of ferries that have been horribly built up and have had enormous bulges built along the sides of the hull. It all goes to increase the waterplane area and ultimately improve the stability of the ship.... of course stability here doesn't mean reducing the amount of rolling. My use of the work 'ducktail' is probably not the most accurate description either because the Vista ships as well as VistaVictoria have a type of duck tail stern. Even QM2 has it... at the waterline... with a rounded cruiser stern above. In theis case the sahpe is adopted as being the best to allow a free run of water from the azipod type propulsion system. Stephen Link to comment Share on other sites More sharing options...
SeaFlint Posted February 3, 2008 #28 Share Posted February 3, 2008 Will these ships meet SOLAS? Angela is right, the Danae was lovely! What about other small, older, classic ships? We saw two in Norway last summer that were lovely - I have as many shots of them in the fjords as I do of QM2. ATHENA and PRINCESS DANAE are indeed part of the same fleet, Classic International Cruises. Five ships, all built between 1948 and 1965! Link to comment Share on other sites More sharing options...
Wadadli1 Posted February 3, 2008 #29 Share Posted February 3, 2008 Will these ships meet SOLAS? Angela is right, the Danae was lovely! What about other small, older, classic ships? We saw two in Norway last summer that were lovely - I have as many shots of them in the fjords as I do of QM2. I took this picture at Barbados in order to get Princess Danae and Mary both in the picture. I would have gotten more of Danae, but they were painting her hull just to the right. And the next is the Danae from the Observation Deck. In that one they were having a lifeboat/crew drill. Busy ship! :) Link to comment Share on other sites More sharing options...
dak Posted February 3, 2008 #30 Share Posted February 3, 2008 Princess Danae at Lisbon 25th April 2006. Taken from Arcadia. David Link to comment Share on other sites More sharing options...
Wadadli1 Posted February 4, 2008 #31 Share Posted February 4, 2008 Thanks. I will. Matthew Does this help at all? The moment of inertia of an object about a given axis describes how difficult it is to change its angular motion about that axis. For example, consider two discs (A and B) of the same mass. Disc A has a larger radius than disc B. Assuming that there is uniform thickness and mass distribution, it requires more effort to accelerate disc A (change its angular velocity) because its mass is distributed further from its axis of rotation: mass that is further out from that axis must, for a given angular velocity, move more quickly than mass closer in. In this case, disc A has a larger moment of inertia than disc B. Divers minimizing their moments of inertia in order to increase their rates of rotation. The moment of inertia of an object can change if its shape changes. A figure skater who begins a spin with arms outstretched provides a striking example. By pulling in her arms, she reduces her moment of inertia, causing her to spin faster (by the conservation of angular momentum). (From Wikipedia, which is at least a good start.) Link to comment Share on other sites More sharing options...
Piton1 Posted February 4, 2008 #32 Share Posted February 4, 2008 Does this help at all? The moment of inertia of an object about a given axis describes how difficult it is to change its angular motion about that axis. For example, consider two discs (A and B) of the same mass. Disc A has a larger radius than disc B. Assuming that there is uniform thickness and mass distribution, it requires more effort to accelerate disc A (change its angular velocity) because its mass is distributed further from its axis of rotation: mass that is further out from that axis must, for a given angular velocity, move more quickly than mass closer in. In this case, disc A has a larger moment of inertia than disc B. Divers minimizing their moments of inertia in order to increase their rates of rotation. The moment of inertia of an object can change if its shape changes. A figure skater who begins a spin with arms outstretched provides a striking example. By pulling in her arms, she reduces her moment of inertia, causing her to spin faster (by the conservation of angular momentum). (From Wikipedia, which is at least a good start.) God, I'm glad I saw Wikipedia here. Paul Link to comment Share on other sites More sharing options...
pb82 Posted February 4, 2008 #33 Share Posted February 4, 2008 Angela, an excellent precis of moment of inertia. However, there is nothing you can do about those encumbered by decades of the stuff. Paul Link to comment Share on other sites More sharing options...
Wadadli1 Posted February 4, 2008 #34 Share Posted February 4, 2008 God, I'm glad I saw Wikipedia here. Paul Excuse me while I go and swallow a band-aid, as my sides are splitting. Har har. Link to comment Share on other sites More sharing options...
Wadadli1 Posted February 4, 2008 #35 Share Posted February 4, 2008 Angela, an excellent precis of moment of inertia. However, there is nothing you can do about those encumbered by decades of the stuff. Paul I'm pretty sure my moment of inertia grows a little larger each year. Link to comment Share on other sites More sharing options...
pb82 Posted February 4, 2008 #36 Share Posted February 4, 2008 I'm pretty sure my moment of inertia grows a little larger each year. The result, no doubt, of distributing the same mass over a taller and more slender frame. Bon Appétit. Link to comment Share on other sites More sharing options...
travel-to-go Posted February 4, 2008 #37 Share Posted February 4, 2008 Doug, Correction and use of technical terms.... The duck's tail stern increases the WATERPLANE AREA of the vessel at normal operating draught and a larger Wp area results in a greater moment of inertia.. I. Bm (Height of) for (Longitudinal stability) is equal to I divided by V where I is the moment of intertia of the waterplane with respect to the transverse axis through its centre of gravity and V is the volume of displacement. Stephen Well, I think I got most of that. I seem to remember the term from Flight School. Also a friend who bought a recumbent bike spoke of the moment of inertia making a recumbent bike actually harder to steer. Same reason a high unicycle is easier to steer than a shorter one. (A good explanation from a tech forum on the bikes: Weight up high is easier to balance because inertia makes it move more slowly than the lighter undercarriage that's more responsive & gives it a little bit of time to get back underneath to restore balance. http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=416&start=30&st=0&sk=t&sd=a) It has to do with the resistance (or lack thereof) of a body to speed up or slow down in a rotational manner- Like the tendency of certain airplanes to roll, based on the wingspan around the "roll axis" (An imaginary line going through the fuselage from the nose to the tail. The GeeBee (by the Granville Brothers) was a plane with a very dangerous moment of inertia. Because of its extremely short wings in relation to its large barrel fuselage, any reproduction cannot be flying models. We had one built here a few years back. I believe whoever had the original plans only agree to let them out on the absolute promise that this plane would not be fly-able. This model was originally made in Springfield Mass. I recently came across info on the field it was made at (on a website of defunct airfields with aerial and ground views of what they look like today. Some were still discernible as airfields, some, sadly, not) Marc also mentioned outriggers on a canoe, which are really more of a combination, I think, of physics principals, though I can't think what at the moment. Thanks Stephen. You made me think, not something I usually do on a Sunday night. It was fun quizzing Marc to see what he remembered (He used to be a helicopter instructor too. Important part of physics with rotor length coming into play! Very interesting subject! Karie Link to comment Share on other sites More sharing options...
Wadadli1 Posted February 4, 2008 #38 Share Posted February 4, 2008 The result, no doubt, of distributing the same mass over a taller and more slender frame. Bon Appétit. But of course. That, and I tend to sprawl more. Link to comment Share on other sites More sharing options...
Rare Germancruiser Posted February 4, 2008 #39 Share Posted February 4, 2008 Hi Angela- you are right, when I watched the ship entereing Barbedos in the morning I first thought this is the Athena and got excited, because of the history of the Stockholm. When I read the name I wasn´t sure if they have renamed it and checked at once in D. Wards Cruise Bibel. LOL. QE 2 is really a nice ship, it is like sailing in a floading museum for me. But 40 years are 40 years- argh and when I thing of this confusing lay out of the decks. Hm. sorry QE2 buffs, I liked the QM 2 much more. Michael Link to comment Share on other sites More sharing options...
Rare Germancruiser Posted February 4, 2008 #40 Share Posted February 4, 2008 Hi Angela- you are right, when I watched the ship entereing Barbedos in the morning I first thought this is the Athena and got excited, because of the history of the Stockholm. When I read the name I wasn´t sure if they have renamed it and checked at once in D. Wards Cruise Bibel. LOL. QE 2 is really a nice ship, it is like sailing in a floading museum for me. But 40 years are 40 years- argh and when I thing of this confusing lay out of the decks. Hm. sorry QE2 buffs, I liked the QM 2 much more. Michael Link to comment Share on other sites More sharing options...
dougnewmanatsea Posted February 4, 2008 #41 Share Posted February 4, 2008 First one is the 'total area of the external surface of the hull'. Waterplane area in that area of a horizontal slice through the hull at the draught she is floating at.Ah, I get it now :) ! It's OK... they don't teach this stuff in schools, A pity. Can you imagine going to Sec School and having the teacher come in a take a class on 'How to build Ocean Liners'?Well, at least I would pay attention, but I'd probably still be terrible at it ;) ! Will these ships meet SOLAS?Yes. George Potamianos, the owner of CIC, is upgrading all his ships so that they will comply with the new regulations coming in force in 2010. (In the case of ATHENA, she was already compliant, so no work has to be done.) What about other small, older, classic ships?It depends on which. Link to comment Share on other sites More sharing options...
SeaFlint Posted February 4, 2008 #42 Share Posted February 4, 2008 ...had a chance to meet (my fault). But I wonder if we stood next to each other on that pier. I recall a couple standing near us while we (I think my wife, kids and I) looked at the Danae. I took this picture at Barbados in order to get Princess Danae and Mary both in the picture. I would have gotten more of Danae, but they were painting her hull just to the right. And the next is the Danae from the Observation Deck. In that one they were having a lifeboat/crew drill. Busy ship! :) Link to comment Share on other sites More sharing options...
Wadadli1 Posted February 4, 2008 #43 Share Posted February 4, 2008 ...had a chance to meet (my fault). But I wonder if we stood next to each other on that pier. I recall a couple standing near us while we (I think my wife, kids and I) looked at the Danae. Was the man wearing a Panama hat with a black ribbon and a turquoise-ish short-sleeved pullover shirt? I think I had on a black skirt and I was wearing this funky knitted Rastafarian hat we'd gotten Olivier for his birthday. I was testing it for comfort. Link to comment Share on other sites More sharing options...
jgsmuzzy Posted February 4, 2008 #44 Share Posted February 4, 2008 Just another couple of shots of Danae, when we were in Barbados. Very nice ship, although not as nice at Blackwatch that was also there at the time. Link to comment Share on other sites More sharing options...
stowaway2k Posted February 5, 2008 #45 Share Posted February 5, 2008 Imperial Majesty's REGAL EMPRESS has some of her beautiful 1950's interiors still intact. Budget cruising, but a dream for ship lovers. Glasgow built for the Greek Line as the OLYMPIA, her maiden voyage was in 1953, her final voyage in service may be 2008 Link to comment Share on other sites More sharing options...
SeaFlint Posted February 5, 2008 #46 Share Posted February 5, 2008 I cannot recall either of those hats. But, then, I might have looked away so as not to make the wearers uncomfortable. ;) Was the man wearing a Panama hat with a black ribbon and a turquoise-ish short-sleeved pullover shirt? I think I had on a black skirt and I was wearing this funky knitted Rastafarian hat we'd gotten Olivier for his birthday. I was testing it for comfort. Link to comment Share on other sites More sharing options...
SeaFlint Posted February 5, 2008 #47 Share Posted February 5, 2008 I cannot recall either of those hats. But, then, I might have looked away so as not to make the wearers uncomfortable. ;) Was the man wearing a Panama hat with a black ribbon and a turquoise-ish short-sleeved pullover shirt? I think I had on a black skirt and I was wearing this funky knitted Rastafarian hat we'd gotten Olivier for his birthday. I was testing it for comfort. Link to comment Share on other sites More sharing options...
Wadadli1 Posted February 5, 2008 #48 Share Posted February 5, 2008 I cannot recall either of those hats. But, then, I might have looked away so as not to make the wearers uncomfortable. ;) We had just come from snorkling and shopping so weren't at our sartorial best, though a lady in the duty-free area said the Rasta hat looked great on me. You don't think she was fibbing, do you? :rolleyes: PS: The Panama hat is very handsome, really. Link to comment Share on other sites More sharing options...
SeaFlint Posted February 5, 2008 #49 Share Posted February 5, 2008 We had just come from snorkling and shopping so weren't at our sartorial best, though a lady in the duty-free area said the Rasta hat looked great on me. You don't think she was fibbing, do you? :rolleyes: PS: The Panama hat is very handsome, really. On the Cat? Link to comment Share on other sites More sharing options...
Wadadli1 Posted February 5, 2008 #50 Share Posted February 5, 2008 On the Cat? Yes. We wanted the tour with turtles and a shipwreck but instead got turtles and rum punch on a catamaran, which was just fine. I did get to pet a turtle, though he was hatless at the time. Link to comment Share on other sites More sharing options...
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