Roger Pellett
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Roger Pellett got a reaction from Larry Cowden in USRC Ranger 1819 by Cathead – FINISHED – Corel – Scale 1:64
Cathead, perhaps this might help. Planking on this type of vessel usually ran up to a horizontal cross seam at the top of the horn timber. not to the transom itself as you show. This required a major twist. Possibly, the manufacturers of the kit sought to eliminate this to simplify construction. The transom sat on top of this, the seam covered by a moulding.
The attached photo shows this same construction in my model of the pilot boat Anna Maria.
Roger Pellett
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Roger Pellett got a reaction from jonny.amy in SS Stephen Hopkins by schooner - FINISHED - BlueJacket Shipcrafters - Liberty Ship
Bob,
The kinked rudder is an example of what naval architects call a contraguide propeller, more specifically a contraguide rudder. The swirling wash coming from a rotating propeller contains kinetic energy. With the propeller operating in open water such as with a twin screw ship this kinetic energy is lost as eventually the water slows down to match that of its surroundings. This energy is then lost.
When this propeller wash is interrupted by an appendage such as the rudder of a single screw ship the flow is affected and some of this kinetic energy is transferred to the ship. In the case is of a single screw ship the rudder captures some of this energy by straightening this flow.
It therefore stands to reason that if the rudder is twisted in a direction opposite to the rotation of the propeller it will be even more effective at straightening this flow and will recapture even more of this lost energy. This "twisted" rudder is therefore an energy saving device.
Given the fact that Liberty ships were supposed to be simple easily built and expendable, it is surprising that they built with this feature. I wonder if the contraguide rudder on the Jeramiah O'brian was added later in her life. Since you are meticulously building a model of a very early Liberty, you might want to see hi she was built with one of these rudders. Your book with all of the design memos might tell you this.
Roger Pellett
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Roger Pellett got a reaction from Canute in Draken Harald Harfage
The difficulties of sailing this large craft with only one sail can only be imagined. There is no way to balance the rig. A high level of seamanship
This ship is supposed to visit us in Duluth in August assuming that they can resolve their pilotage issue. It is hard to imagine what expertise a pilot used to piloting foreign diesel engined vessels could apply to this single sailed shallow draft vessel.
Roger Pellett
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Roger Pellett got a reaction from WackoWolf in SS Stephen Hopkins by schooner - FINISHED - BlueJacket Shipcrafters - Liberty Ship
Bob,
The kinked rudder is an example of what naval architects call a contraguide propeller, more specifically a contraguide rudder. The swirling wash coming from a rotating propeller contains kinetic energy. With the propeller operating in open water such as with a twin screw ship this kinetic energy is lost as eventually the water slows down to match that of its surroundings. This energy is then lost.
When this propeller wash is interrupted by an appendage such as the rudder of a single screw ship the flow is affected and some of this kinetic energy is transferred to the ship. In the case is of a single screw ship the rudder captures some of this energy by straightening this flow.
It therefore stands to reason that if the rudder is twisted in a direction opposite to the rotation of the propeller it will be even more effective at straightening this flow and will recapture even more of this lost energy. This "twisted" rudder is therefore an energy saving device.
Given the fact that Liberty ships were supposed to be simple easily built and expendable, it is surprising that they built with this feature. I wonder if the contraguide rudder on the Jeramiah O'brian was added later in her life. Since you are meticulously building a model of a very early Liberty, you might want to see hi she was built with one of these rudders. Your book with all of the design memos might tell you this.
Roger Pellett
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Roger Pellett got a reaction from Elijah in SS Stephen Hopkins by schooner - FINISHED - BlueJacket Shipcrafters - Liberty Ship
Bob,
The kinked rudder is an example of what naval architects call a contraguide propeller, more specifically a contraguide rudder. The swirling wash coming from a rotating propeller contains kinetic energy. With the propeller operating in open water such as with a twin screw ship this kinetic energy is lost as eventually the water slows down to match that of its surroundings. This energy is then lost.
When this propeller wash is interrupted by an appendage such as the rudder of a single screw ship the flow is affected and some of this kinetic energy is transferred to the ship. In the case is of a single screw ship the rudder captures some of this energy by straightening this flow.
It therefore stands to reason that if the rudder is twisted in a direction opposite to the rotation of the propeller it will be even more effective at straightening this flow and will recapture even more of this lost energy. This "twisted" rudder is therefore an energy saving device.
Given the fact that Liberty ships were supposed to be simple easily built and expendable, it is surprising that they built with this feature. I wonder if the contraguide rudder on the Jeramiah O'brian was added later in her life. Since you are meticulously building a model of a very early Liberty, you might want to see hi she was built with one of these rudders. Your book with all of the design memos might tell you this.
Roger Pellett
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Roger Pellett got a reaction from Rick01 in Draken Harald Harfage
The difficulties of sailing this large craft with only one sail can only be imagined. There is no way to balance the rig. A high level of seamanship
This ship is supposed to visit us in Duluth in August assuming that they can resolve their pilotage issue. It is hard to imagine what expertise a pilot used to piloting foreign diesel engined vessels could apply to this single sailed shallow draft vessel.
Roger Pellett
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Roger Pellett got a reaction from mtaylor in No modern materials for sails?
The following is offered for what it's worth, without getting into a discussion about exactly constitutes scale. I went through a variety of materials in my stash and measured thicknesses with a set of digital calipers. Results are approximate for a number of reasons including the amount of pressure on the calipers. I tried ro keep it light.
No. 10 duck canvas left over from a canoe restoration job. .032in. At 1:32 scale that I am building to, this would require a material of .001in.
Unidentified tightly woven unbleached muslin type material from a fabric shop. .005in
Drafting linen (or cotton) with the starch washed out. Some actually liberated from the old US Navy Bureau of Ships trash. This has a nice even weave with no "pics".
.002in
Oriental rice paper .001in
Lightweight silk span from a 30+ year old model airplane kit. .001in.
I am building a 1:32 navy longboat that I plan to display with furled sails. I will probably use drafting linen for the main sail and stay sail and rice paper for the flying jib.
Roger Pellett
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Roger Pellett got a reaction from davyboy in Draken Harald Harfage
The difficulties of sailing this large craft with only one sail can only be imagined. There is no way to balance the rig. A high level of seamanship
This ship is supposed to visit us in Duluth in August assuming that they can resolve their pilotage issue. It is hard to imagine what expertise a pilot used to piloting foreign diesel engined vessels could apply to this single sailed shallow draft vessel.
Roger Pellett
-
Roger Pellett got a reaction from mtaylor in Draken Harald Harfage
The difficulties of sailing this large craft with only one sail can only be imagined. There is no way to balance the rig. A high level of seamanship
This ship is supposed to visit us in Duluth in August assuming that they can resolve their pilotage issue. It is hard to imagine what expertise a pilot used to piloting foreign diesel engined vessels could apply to this single sailed shallow draft vessel.
Roger Pellett
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Roger Pellett got a reaction from Doreltomin in No modern materials for sails?
The following is offered for what it's worth, without getting into a discussion about exactly constitutes scale. I went through a variety of materials in my stash and measured thicknesses with a set of digital calipers. Results are approximate for a number of reasons including the amount of pressure on the calipers. I tried ro keep it light.
No. 10 duck canvas left over from a canoe restoration job. .032in. At 1:32 scale that I am building to, this would require a material of .001in.
Unidentified tightly woven unbleached muslin type material from a fabric shop. .005in
Drafting linen (or cotton) with the starch washed out. Some actually liberated from the old US Navy Bureau of Ships trash. This has a nice even weave with no "pics".
.002in
Oriental rice paper .001in
Lightweight silk span from a 30+ year old model airplane kit. .001in.
I am building a 1:32 navy longboat that I plan to display with furled sails. I will probably use drafting linen for the main sail and stay sail and rice paper for the flying jib.
Roger Pellett
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Roger Pellett got a reaction from dgbot in No modern materials for sails?
The following is offered for what it's worth, without getting into a discussion about exactly constitutes scale. I went through a variety of materials in my stash and measured thicknesses with a set of digital calipers. Results are approximate for a number of reasons including the amount of pressure on the calipers. I tried ro keep it light.
No. 10 duck canvas left over from a canoe restoration job. .032in. At 1:32 scale that I am building to, this would require a material of .001in.
Unidentified tightly woven unbleached muslin type material from a fabric shop. .005in
Drafting linen (or cotton) with the starch washed out. Some actually liberated from the old US Navy Bureau of Ships trash. This has a nice even weave with no "pics".
.002in
Oriental rice paper .001in
Lightweight silk span from a 30+ year old model airplane kit. .001in.
I am building a 1:32 navy longboat that I plan to display with furled sails. I will probably use drafting linen for the main sail and stay sail and rice paper for the flying jib.
Roger Pellett
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Roger Pellett reacted to Cathead in USRC Ranger 1819 by Cathead – FINISHED – Corel – Scale 1:64
Roger, thanks. I think I have enough information to move ahead with something that will be better than the original, if not entirely prototypical. I'm going to try to mimic the Louisiana drawing above, in part. Hopefully I'll show some progress this weekend.
I very much appreciate your willingness to advise amateur projects like mine.
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Roger Pellett got a reaction from FriedClams in USRC Ranger 1819 by Cathead – FINISHED – Corel – Scale 1:64
Hi Carhead,
Two pictures added, hopefully better than the last. It looks like someday, I need to take the model out of the case to dust, but not today.
I don't think that there is any way to build this kit to accurately represent actual practice without major surgery. Assuming that the bottom of your transom now sits on the horn timber, you need to erect angular knees on top of it. These knees will be at an oblique angle equaling the sum of the rise of the sheer line and the slope of th transom. The lower part of these knees should be cross planked and the transom will be fixed to the upper. Since this vessel has no bulwarks, the transom will appear perched up somewhat as shown in the Lousiana picture above.
Roger
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Roger Pellett got a reaction from Larry Cowden in USRC Ranger 1819 by Cathead – FINISHED – Corel – Scale 1:64
Hi Cathead,
Sorry, taking pictures through a glass case is difficult. Tomorrow AM I'll try to get a better picture outdoors.
Furthermore, my description was incorrect. The hull planking does twist up to the top of the horn timber but the transom does not sit directly on top of the horn timber. Instead, there is a series of transom knees that mortise into the top of the timber. The lower part (the more horizontal section) of the knees is cross planked and the rudder head passes through this area. The transom is fastened to the upper section of these knees. The profile of the Louisiana that you posted above shows this arrangement.
This arrangement accomplishes two things. First the structure protects the rudder head. Second, it moves the main sheet aft of the rudder head. As you will recall from building your longboat, otherwise, the sheet interferes with the tiller
Roger
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Roger Pellett got a reaction from FriedClams in USRC Ranger 1819 by Cathead – FINISHED – Corel – Scale 1:64
Cathead, perhaps this might help. Planking on this type of vessel usually ran up to a horizontal cross seam at the top of the horn timber. not to the transom itself as you show. This required a major twist. Possibly, the manufacturers of the kit sought to eliminate this to simplify construction. The transom sat on top of this, the seam covered by a moulding.
The attached photo shows this same construction in my model of the pilot boat Anna Maria.
Roger Pellett
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Roger Pellett got a reaction from mattsayers148 in USRC Ranger 1819 by Cathead – FINISHED – Corel – Scale 1:64
Hi Carhead,
Two pictures added, hopefully better than the last. It looks like someday, I need to take the model out of the case to dust, but not today.
I don't think that there is any way to build this kit to accurately represent actual practice without major surgery. Assuming that the bottom of your transom now sits on the horn timber, you need to erect angular knees on top of it. These knees will be at an oblique angle equaling the sum of the rise of the sheer line and the slope of th transom. The lower part of these knees should be cross planked and the transom will be fixed to the upper. Since this vessel has no bulwarks, the transom will appear perched up somewhat as shown in the Lousiana picture above.
Roger
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Roger Pellett got a reaction from ggrieco in USRC Ranger 1819 by Cathead – FINISHED – Corel – Scale 1:64
Hi Carhead,
Two pictures added, hopefully better than the last. It looks like someday, I need to take the model out of the case to dust, but not today.
I don't think that there is any way to build this kit to accurately represent actual practice without major surgery. Assuming that the bottom of your transom now sits on the horn timber, you need to erect angular knees on top of it. These knees will be at an oblique angle equaling the sum of the rise of the sheer line and the slope of th transom. The lower part of these knees should be cross planked and the transom will be fixed to the upper. Since this vessel has no bulwarks, the transom will appear perched up somewhat as shown in the Lousiana picture above.
Roger
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Roger Pellett got a reaction from FriedClams in USRC Ranger 1819 by Cathead – FINISHED – Corel – Scale 1:64
Hi Cathead,
Sorry, taking pictures through a glass case is difficult. Tomorrow AM I'll try to get a better picture outdoors.
Furthermore, my description was incorrect. The hull planking does twist up to the top of the horn timber but the transom does not sit directly on top of the horn timber. Instead, there is a series of transom knees that mortise into the top of the timber. The lower part (the more horizontal section) of the knees is cross planked and the rudder head passes through this area. The transom is fastened to the upper section of these knees. The profile of the Louisiana that you posted above shows this arrangement.
This arrangement accomplishes two things. First the structure protects the rudder head. Second, it moves the main sheet aft of the rudder head. As you will recall from building your longboat, otherwise, the sheet interferes with the tiller
Roger
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Roger Pellett got a reaction from Mike Dowling in Chaperon 1894 by Mike Dowling - FINISHED - Model Shipways - Sternwheeler Steamer
A variation of Kurt's color scheme for the decks that you might wish to consider would be a darker red for the decks (the paddle wheels are bright red). Red iron oxide has been used for many years here in the US as an industrial paint. It has one major virtue, it is cheap! The pigment used for this paint is iron oxide an abundant natural mineral. It has been used since Colonial times. At one time most barns in the US were painted with this paint, and here on the lakes it was and still is a favorite color for shipboard use. For many years, I worked for companies that built piping systems for industrial applications and this was used as a construction primer to protect the piping until it could be erected and insulated. When proprietary paint was costing us over $35 per gallon, this stuff cost $14 from a local paint manufacturer.
I don't know what is available to you in Great Britain but here in the US this color is widely available in spray cans as a metal primer.
Several years ago Eric Ronnberg published a set of color chips that included this color in the Nautical Research Journal and I believe that it has been reproduced on their website.
Roger Pellett
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Roger Pellett got a reaction from mattsayers148 in USRC Ranger 1819 by Cathead – FINISHED – Corel – Scale 1:64
Hi Cathead,
Sorry, taking pictures through a glass case is difficult. Tomorrow AM I'll try to get a better picture outdoors.
Furthermore, my description was incorrect. The hull planking does twist up to the top of the horn timber but the transom does not sit directly on top of the horn timber. Instead, there is a series of transom knees that mortise into the top of the timber. The lower part (the more horizontal section) of the knees is cross planked and the rudder head passes through this area. The transom is fastened to the upper section of these knees. The profile of the Louisiana that you posted above shows this arrangement.
This arrangement accomplishes two things. First the structure protects the rudder head. Second, it moves the main sheet aft of the rudder head. As you will recall from building your longboat, otherwise, the sheet interferes with the tiller
Roger
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Roger Pellett got a reaction from WackoWolf in Chaperon 1894 by Mike Dowling - FINISHED - Model Shipways - Sternwheeler Steamer
A variation of Kurt's color scheme for the decks that you might wish to consider would be a darker red for the decks (the paddle wheels are bright red). Red iron oxide has been used for many years here in the US as an industrial paint. It has one major virtue, it is cheap! The pigment used for this paint is iron oxide an abundant natural mineral. It has been used since Colonial times. At one time most barns in the US were painted with this paint, and here on the lakes it was and still is a favorite color for shipboard use. For many years, I worked for companies that built piping systems for industrial applications and this was used as a construction primer to protect the piping until it could be erected and insulated. When proprietary paint was costing us over $35 per gallon, this stuff cost $14 from a local paint manufacturer.
I don't know what is available to you in Great Britain but here in the US this color is widely available in spray cans as a metal primer.
Several years ago Eric Ronnberg published a set of color chips that included this color in the Nautical Research Journal and I believe that it has been reproduced on their website.
Roger Pellett
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Roger Pellett got a reaction from mtaylor in Chaperon 1894 by Mike Dowling - FINISHED - Model Shipways - Sternwheeler Steamer
A variation of Kurt's color scheme for the decks that you might wish to consider would be a darker red for the decks (the paddle wheels are bright red). Red iron oxide has been used for many years here in the US as an industrial paint. It has one major virtue, it is cheap! The pigment used for this paint is iron oxide an abundant natural mineral. It has been used since Colonial times. At one time most barns in the US were painted with this paint, and here on the lakes it was and still is a favorite color for shipboard use. For many years, I worked for companies that built piping systems for industrial applications and this was used as a construction primer to protect the piping until it could be erected and insulated. When proprietary paint was costing us over $35 per gallon, this stuff cost $14 from a local paint manufacturer.
I don't know what is available to you in Great Britain but here in the US this color is widely available in spray cans as a metal primer.
Several years ago Eric Ronnberg published a set of color chips that included this color in the Nautical Research Journal and I believe that it has been reproduced on their website.
Roger Pellett
-
Roger Pellett got a reaction from mattsayers148 in USRC Ranger 1819 by Cathead – FINISHED – Corel – Scale 1:64
Cathead, perhaps this might help. Planking on this type of vessel usually ran up to a horizontal cross seam at the top of the horn timber. not to the transom itself as you show. This required a major twist. Possibly, the manufacturers of the kit sought to eliminate this to simplify construction. The transom sat on top of this, the seam covered by a moulding.
The attached photo shows this same construction in my model of the pilot boat Anna Maria.
Roger Pellett
-
Roger Pellett got a reaction from Cathead in Chaperon 1894 by Mike Dowling - FINISHED - Model Shipways - Sternwheeler Steamer
A variation of Kurt's color scheme for the decks that you might wish to consider would be a darker red for the decks (the paddle wheels are bright red). Red iron oxide has been used for many years here in the US as an industrial paint. It has one major virtue, it is cheap! The pigment used for this paint is iron oxide an abundant natural mineral. It has been used since Colonial times. At one time most barns in the US were painted with this paint, and here on the lakes it was and still is a favorite color for shipboard use. For many years, I worked for companies that built piping systems for industrial applications and this was used as a construction primer to protect the piping until it could be erected and insulated. When proprietary paint was costing us over $35 per gallon, this stuff cost $14 from a local paint manufacturer.
I don't know what is available to you in Great Britain but here in the US this color is widely available in spray cans as a metal primer.
Several years ago Eric Ronnberg published a set of color chips that included this color in the Nautical Research Journal and I believe that it has been reproduced on their website.
Roger Pellett
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Roger Pellett reacted to BANYAN in HMS Dreadnought 1907 by RGL - FINISHED - Zvezda - 1/350- PLASTIC
You don't muck around with these builds do you Greg! This will be a great looking model.
cheers
Pat
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