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#1
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I don't think it is quite ready for prime time yet but here is an
interesting idea. A small retractable Voith-Schneider drive like those used on modern tugs. Retracts flat into the hull and when extended will deliver thrust in any direction. http://www.spw-gmbh.de/en/hb/ -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
#2
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Interesting. It's amazing to watch a vessel equipped with a VS drive --
they really can go in any direction with full thrust. I'd worry about efficiency -- the end plate is a larger problem in a small one than in a large one, a VS is not as efficient as a propeller, and you'd probably have to go diesel electric or diesel hydraulic in order to retract it, and both are lossy. Do you know what it costs? -- Jim Woodward www.mvFintry.com .. "Glenn Ashmore" wrote in message news:JDPqb.10756$62.1728@lakeread04... I don't think it is quite ready for prime time yet but here is an interesting idea. A small retractable Voith-Schneider drive like those used on modern tugs. Retracts flat into the hull and when extended will deliver thrust in any direction. http://www.spw-gmbh.de/en/hb/ -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
#3
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![]() Jim Woodward wrote: Interesting. It's amazing to watch a vessel equipped with a VS drive -- they really can go in any direction with full thrust. I'd worry about efficiency -- the end plate is a larger problem in a small one than in a large one, a VS is not as efficient as a propeller, and you'd probably have to go diesel electric or diesel hydraulic in order to retract it, and both are lossy. Do you know what it costs? That's why I said it was not ready for prime time. It would be fun to dock though. Especially with a retractable bow thruster. A pas de bouree up to the end of the pier and with a quick piorette and a short petit jete you are into your slip. (Tutus and leotards optional) The web site said to contact about prices and if it were objectionable they would let you know when the production gets above 10 in a batch. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
#4
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"Glenn Ashmore" wrote in message
news:ghSqb.10765$62.10532@lakeread04... Jim Woodward wrote: Interesting. It's amazing to watch a vessel equipped with a VS drive -- they really can go in any direction with full thrust. I'd worry about efficiency -- the end plate is a larger problem in a small one than in a large one, a VS is not as efficient as a propeller, and you'd probably have to go diesel electric or diesel hydraulic in order to retract it, and both are lossy. Do you know what it costs? That's why I said it was not ready for prime time. It would be fun to dock though. Especially with a retractable bow thruster. A pas de bouree up to the end of the pier and with a quick piorette and a short petit jete you are into your slip. (Tutus and leotards optional) The web site said to contact about prices and if it were objectionable they would let you know when the production gets above 10 in a batch. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com Changing the subject totally: Raphael Semmes, in his account of the CSS Alabama, mentions on several occasions of fitting the propeller (maybe he used the word screw, not sure) before making steam. Anyone have a clue what he meant. Did they actually remove the screw and shaft when sailing. If so, how, without stopping and sending divers down, which they obviously didn't do. Or did they simply disengage the screw from the drive shaft so it free wheeled, and then needed to reattach, perhaps lacking a clutching means? Or did the shaft pivot on a u-joint near the packing gland and could be pivoted so the screw was above the water line? Anyone know or have other ideas? Anyone else care? Ray (btw, I will definitely try Duke's in Ridgeway this Spring when in Charleston, hope a good thing isn't being spoiled here. Can you say Wreck) |
#5
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Don't sell us Southern good ol' boys or our BBQ short. The CSS Alabama
had a retractable propeller for better efficiency under sail. (Beats the heck out of a feathering prop.) It was disconnected from the shaft and hoisted under the fantail on a rail assembly. It could be lowered and pinned to the shaft rather quickly. The Alabama had several other inovations. It could change its rig at will to disguise itself and had a retractable stack so that it could look like a pure sailing vessel. The Alabama was built in England but I think James Bulloch, the Confederate representative, got credit for the ideas. At least he does around heah. :-) BTW, Gov. Dean, I don't have a Confederate flag on my Japaneese pickup but I do understand what you are trying to say. :-) BF wrote: Changing the subject totally: Raphael Semmes, in his account of the CSS Alabama, mentions on several occasions of fitting the propeller (maybe he used the word screw, not sure) before making steam. Anyone have a clue what he meant. Did they actually remove the screw and shaft when sailing. If so, how, without stopping and sending divers down, which they obviously didn't do. Or did they simply disengage the screw from the drive shaft so it free wheeled, and then needed to reattach, perhaps lacking a clutching means? Or did the shaft pivot on a u-joint near the packing gland and could be pivoted so the screw was above the water line? Anyone know or have other ideas? Anyone else care? Ray (btw, I will definitely try Duke's in Ridgeway this Spring when in Charleston, hope a good thing isn't being spoiled here. Can you say Wreck) -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
#6
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You imply that I'm a yankee and I take offense.
Let it be known that my great grand daddy (several times back) was one of Houston's heroes at San Jacinto and I do know good BBQ. Not sure which should cause more offense. Back to the Alabama: HOW was it disconnected and reattached. The rail thing makes sense but the attachment had to be under water, doesn't it? Rather quickly is somewhat subjective, I think. Since Semmes mentions it several times, it implies that it wasn't an easy task like shoveling several hundred pounds of coal to raise steam. Granted it was new technology but that doesn't seem to be Semmes focus. I don't recall him mentioning the "why" of the removable propeller. Ray "Glenn Ashmore" wrote in message news:fvUqb.10776$62.3537@lakeread04... Don't sell us Southern good ol' boys or our BBQ short. The CSS Alabama had a retractable propeller for better efficiency under sail. (Beats the heck out of a feathering prop.) It was disconnected from the shaft and hoisted under the fantail on a rail assembly. It could be lowered and pinned to the shaft rather quickly. The Alabama had several other inovations. It could change its rig at will to disguise itself and had a retractable stack so that it could look like a pure sailing vessel. The Alabama was built in England but I think James Bulloch, the Confederate representative, got credit for the ideas. At least he does around heah. :-) BTW, Gov. Dean, I don't have a Confederate flag on my Japaneese pickup but I do understand what you are trying to say. :-) BF wrote: Changing the subject totally: Raphael Semmes, in his account of the CSS Alabama, mentions on several occasions of fitting the propeller (maybe he used the word screw, not sure) before making steam. Anyone have a clue what he meant. Did they actually remove the screw and shaft when sailing. If so, how, without stopping and sending divers down, which they obviously didn't do. Or did they simply disengage the screw from the drive shaft so it free wheeled, and then needed to reattach, perhaps lacking a clutching means? Or did the shaft pivot on a u-joint near the packing gland and could be pivoted so the screw was above the water line? Anyone know or have other ideas? Anyone else care? Ray (btw, I will definitely try Duke's in Ridgeway this Spring when in Charleston, hope a good thing isn't being spoiled here. Can you say Wreck) -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
#7
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![]() "Glenn Ashmore" wrote in message news:fvUqb.10776$62.3537@lakeread04... Don't sell us Southern good ol' boys or our BBQ short. The CSS Alabama had a retractable propeller for better efficiency under sail. (Beats the heck out of a feathering prop.) It was disconnected from the shaft and hoisted under the fantail on a rail assembly. It could be lowered and pinned to the shaft rather quickly. The HMS Warrior which is in Portsmouth had the same kind of system .When all sail was called they would unpin the screw from the shaft and crank it up out of the water on a special railway. I have read someplace that it was a bit of a pain to do.. Neil Currey Building a Dix design Pratique 35 |
#8
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I don't know Alabama at all, but perhaps I can shed some light:
Great Britain (first iron screw steamship, launched in Bristol, 1843, now back in Bristol, see http://www.ss-great-britain.com/) was refitted in 1857 for the Australian trade, which required that she sail well. To accomplish this she had a lifting screw. Perhaps Glenn should consider this for Rutu instead of a MaxProp. Take a propeller with a stub shaft, fore and aft. Put bearings on both ends and a square on the forward end. Hang the bearings on a frame that can be lifted straight up in channels. In order to raise the propeller for sailing, you: 1) remove a short section of shaft inside the vessel. 2) slide the tailshaft forward 3) raise the frame with tackle. To operate under power, it's the reverse, except that when sliding the tailshaft aft, you have to engage the square on the stub shaft in a hollow on the end of the tailshaft. That's how it's described in the text of The Story of Brunel's SS Great Britain, Ewan Corlett, Conway Maritime, 1990. However, a drawing by Basil Greenhill in the same book shows a dog clutch rather than the square. The Great Britain museum is a wonderful view into the first large ocean going screw vessel -- it's a great story, as she was rescued from the Falkland Islands where she rusted from 1886 until 1970. -- Jim Woodward www.mvFintry.com .. "BF" wrote in message ... "Glenn Ashmore" wrote in message news:ghSqb.10765$62.10532@lakeread04... Jim Woodward wrote: Interesting. It's amazing to watch a vessel equipped with a VS drive -- they really can go in any direction with full thrust. I'd worry about efficiency -- the end plate is a larger problem in a small one than in a large one, a VS is not as efficient as a propeller, and you'd probably have to go diesel electric or diesel hydraulic in order to retract it, and both are lossy. Do you know what it costs? That's why I said it was not ready for prime time. It would be fun to dock though. Especially with a retractable bow thruster. A pas de bouree up to the end of the pier and with a quick piorette and a short petit jete you are into your slip. (Tutus and leotards optional) The web site said to contact about prices and if it were objectionable they would let you know when the production gets above 10 in a batch. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com Changing the subject totally: Raphael Semmes, in his account of the CSS Alabama, mentions on several occasions of fitting the propeller (maybe he used the word screw, not sure) before making steam. Anyone have a clue what he meant. Did they actually remove the screw and shaft when sailing. If so, how, without stopping and sending divers down, which they obviously didn't do. Or did they simply disengage the screw from the drive shaft so it free wheeled, and then needed to reattach, perhaps lacking a clutching means? Or did the shaft pivot on a u-joint near the packing gland and could be pivoted so the screw was above the water line? Anyone know or have other ideas? Anyone else care? Ray (btw, I will definitely try Duke's in Ridgeway this Spring when in Charleston, hope a good thing isn't being spoiled here. Can you say Wreck) |
#9
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Thanks Jim,
That explanation makes a bit of sense, need to see the pictures to understand better though. I've ordered the Corlett book from my library, looking forward to reading it. Ray "Jim Woodward" jameslwoodward at attbi dot com wrote in message ... I don't know Alabama at all, but perhaps I can shed some light: Great Britain (first iron screw steamship, launched in Bristol, 1843, now back in Bristol, see http://www.ss-great-britain.com/) was refitted in 1857 for the Australian trade, which required that she sail well. To accomplish this she had a lifting screw. Perhaps Glenn should consider this for Rutu instead of a MaxProp. Take a propeller with a stub shaft, fore and aft. Put bearings on both ends and a square on the forward end. Hang the bearings on a frame that can be lifted straight up in channels. In order to raise the propeller for sailing, you: 1) remove a short section of shaft inside the vessel. 2) slide the tailshaft forward 3) raise the frame with tackle. To operate under power, it's the reverse, except that when sliding the tailshaft aft, you have to engage the square on the stub shaft in a hollow on the end of the tailshaft. That's how it's described in the text of The Story of Brunel's SS Great Britain, Ewan Corlett, Conway Maritime, 1990. However, a drawing by Basil Greenhill in the same book shows a dog clutch rather than the square. The Great Britain museum is a wonderful view into the first large ocean going screw vessel -- it's a great story, as she was rescued from the Falkland Islands where she rusted from 1886 until 1970. -- Jim Woodward www.mvFintry.com . "BF" wrote in message ... "Glenn Ashmore" wrote in message news:ghSqb.10765$62.10532@lakeread04... Jim Woodward wrote: Interesting. It's amazing to watch a vessel equipped with a VS drive -- they really can go in any direction with full thrust. I'd worry about efficiency -- the end plate is a larger problem in a small one than in a large one, a VS is not as efficient as a propeller, and you'd probably have to go diesel electric or diesel hydraulic in order to retract it, and both are lossy. Do you know what it costs? That's why I said it was not ready for prime time. It would be fun to dock though. Especially with a retractable bow thruster. A pas de bouree up to the end of the pier and with a quick piorette and a short petit jete you are into your slip. (Tutus and leotards optional) The web site said to contact about prices and if it were objectionable they would let you know when the production gets above 10 in a batch. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com Changing the subject totally: Raphael Semmes, in his account of the CSS Alabama, mentions on several occasions of fitting the propeller (maybe he used the word screw, not sure) before making steam. Anyone have a clue what he meant. Did they actually remove the screw and shaft when sailing. If so, how, without stopping and sending divers down, which they obviously didn't do. Or did they simply disengage the screw from the drive shaft so it free wheeled, and then needed to reattach, perhaps lacking a clutching means? Or did the shaft pivot on a u-joint near the packing gland and could be pivoted so the screw was above the water line? Anyone know or have other ideas? Anyone else care? Ray (btw, I will definitely try Duke's in Ridgeway this Spring when in Charleston, hope a good thing isn't being spoiled here. Can you say Wreck) |
#10
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Glenn Ashmore wrote:
I don't think it is quite ready for prime time yet but here is an interesting idea. A small retractable Voith-Schneider drive like those used on modern tugs. Retracts flat into the hull and when extended will deliver thrust in any direction. http://www.spw-gmbh.de/en/hb/ Boy, that thing takes up a BUNCH of height (27+")! (I think I have room enough under the cockpit, though.) And if it can only drive a 32' boat to 5 knots without overheating (if I interpret correctly, English is not their first language), there's something seriously wrong right now. We do 5 knots using only .2 gph, which calculates to somewhat under 7 HP. And 380v AC onboard isn't my favorite thing. In the power industry, anything over 220 required pretty special precautions. Still, when they get things smoothed out, it could be a very interesting system. -- Jere Lull Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD) Xan's Pages: http://members.dca.net/jerelull/X-Main.html Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/ |
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