Roger Pellett
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Roger Pellett got a reaction from BETAQDAVE in SS Stephen Hopkins by schooner - FINISHED - BlueJacket Shipcrafters - Liberty Ship
Nope, the offset rudder is an intentional design feature called a contravene rudder. It is a form of contravene propeller, a term described in the SNAME glossary of maritime terms. Any water behind the propeller moving faster than the undisturbed water surrounding the ship contains kinetic energy and in addition to steering the ship this rudder's job is to maximize recovery of this kinetic energy by straightening the flow.
A photo of the American Victory in dry dock shows this same rudder feature. This photo was published in the NRJ several years ago.
In PN Thomas's British Tramps, Volume I general arrangement drawings of Liberty ships do not indicate this feature. In fact the Liberty's British predessor appears to have a single plate rudder. Thomas also says that a number of Liberty ship rudders failed and the rudder was redesigned late in the war. So the American Liberty's rudders were redesigned. The question is whether this feature was incorporated when the Americans revised the British design or was it added when the rudders were revised late in the war.
Roger Pellett
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Roger Pellett got a reaction from mtaylor in Royal Caroline, deck covering
Canvas covered decks have been used on yachts even into relatively modern times. L. Francis Herreshoff was a proponent of these, and in the late 1940's my father built a Herreshoff designed Prudence H-22 sailboat with a canvas covered deck set in paint. Wooden Boat had an article on the subject several years ago. A few years ago there was a Herreshoff H-28 ketch here in the harbor. It had a teak deck sprung into a king plank and it looked totally out-of-place. Herreshoff would have disapproved. The modern plywood decks with synthetic fabric set in epoxy are direct descendants of these canvas covered decks.
I would think that a canvas covered deck on a royal yacht would be an entirely practical moth of for protecting passengers and furnishings below, and decorating it with paints would be a plus.
Roger Pellett
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Roger Pellett got a reaction from Piet in SS Kaiser Wilhelm der Grosse 1897 by Mirabell61 - FINISHED - scale 1:144 - POF - first German four stacker of the Norddeutscher Lloyd line
I am not particularly interested in Titanic lore but I did buy and read a copy of Titanic Ships Titanic Disasters, a serious examination of Titanic's design and sinking by a forensic naval architect and a marine engineer, John Woodward who taught marine machinery courses at the University of Michigan to budding marine engineers including this correspondent. This book is in my opinion essential reading for those interested in Titanic and large passenger vessels in general. The book is published by the Society of Naval Architects and Marine Engineers here in the US.
The authors conclude that Titanic was a successful design. She was specified as a two compartment ship. The gash flooded six. She sank on an even keel and allowed her life boats to be launched (with the possible exception of the collapsible boats), and her power plant continue to function providing steam end electric lighting until the end. A couple of "improved Titanic" designs actually fared worse by capsizing before sinking.
Titanic's deficiency was that she was not properly outfitted. Her owners chose not to provide sufficient lifeboats.
Roger Pellett
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Roger Pellett got a reaction from Martin W in SS Kaiser Wilhelm der Grosse 1897 by Mirabell61 - FINISHED - scale 1:144 - POF - first German four stacker of the Norddeutscher Lloyd line
I am not particularly interested in Titanic lore but I did buy and read a copy of Titanic Ships Titanic Disasters, a serious examination of Titanic's design and sinking by a forensic naval architect and a marine engineer, John Woodward who taught marine machinery courses at the University of Michigan to budding marine engineers including this correspondent. This book is in my opinion essential reading for those interested in Titanic and large passenger vessels in general. The book is published by the Society of Naval Architects and Marine Engineers here in the US.
The authors conclude that Titanic was a successful design. She was specified as a two compartment ship. The gash flooded six. She sank on an even keel and allowed her life boats to be launched (with the possible exception of the collapsible boats), and her power plant continue to function providing steam end electric lighting until the end. A couple of "improved Titanic" designs actually fared worse by capsizing before sinking.
Titanic's deficiency was that she was not properly outfitted. Her owners chose not to provide sufficient lifeboats.
Roger Pellett
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Roger Pellett got a reaction from druxey in Royal Caroline, deck covering
Canvas covered decks have been used on yachts even into relatively modern times. L. Francis Herreshoff was a proponent of these, and in the late 1940's my father built a Herreshoff designed Prudence H-22 sailboat with a canvas covered deck set in paint. Wooden Boat had an article on the subject several years ago. A few years ago there was a Herreshoff H-28 ketch here in the harbor. It had a teak deck sprung into a king plank and it looked totally out-of-place. Herreshoff would have disapproved. The modern plywood decks with synthetic fabric set in epoxy are direct descendants of these canvas covered decks.
I would think that a canvas covered deck on a royal yacht would be an entirely practical moth of for protecting passengers and furnishings below, and decorating it with paints would be a plus.
Roger Pellett
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Roger Pellett reacted to Mark P in Royal Caroline, deck covering
Hi Roger;
Thank you for the comment, that is interesting. I will remember what you say.
All the best,
Mark P
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Roger Pellett got a reaction from Mark P in Royal Caroline, deck covering
Canvas covered decks have been used on yachts even into relatively modern times. L. Francis Herreshoff was a proponent of these, and in the late 1940's my father built a Herreshoff designed Prudence H-22 sailboat with a canvas covered deck set in paint. Wooden Boat had an article on the subject several years ago. A few years ago there was a Herreshoff H-28 ketch here in the harbor. It had a teak deck sprung into a king plank and it looked totally out-of-place. Herreshoff would have disapproved. The modern plywood decks with synthetic fabric set in epoxy are direct descendants of these canvas covered decks.
I would think that a canvas covered deck on a royal yacht would be an entirely practical moth of for protecting passengers and furnishings below, and decorating it with paints would be a plus.
Roger Pellett
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Roger Pellett got a reaction from Piet in SS Stephen Hopkins by schooner - FINISHED - BlueJacket Shipcrafters - Liberty Ship
Learning something new whether a new technique or more about the vessel that you are modeling is what makes this hobby so fascinating.
Roger
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Roger Pellett got a reaction from Piet in SS Kaiser Wilhelm der Grosse 1897 by Mirabell61 - FINISHED - scale 1:144 - POF - first German four stacker of the Norddeutscher Lloyd line
Nils,
If you don't mind using plastic sheet you might consider using the model boat that you bought to vacuum form the boats. I would led recommend forming them in port and starboard halves. You would have to cut your model longitudinally in half. When the formed halves are cut from the flat sheet you have a nice little flange on each side to glue together that can then be shaped for the keel. The thwarts and air tank top can then be cut out as sa third piece and glued into the top.with your abilities, I'm sure that you would have no trouble mass producing them.
If you have not used vacuum forming it is simple, and foolproof. A shop vacuum provides plenty of suction. You can produce a wonderfully light delicate boat that will look even better than the model that you bought.
Roger
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Roger Pellett got a reaction from Elijah in SS Stephen Hopkins by schooner - FINISHED - BlueJacket Shipcrafters - Liberty Ship
Learning something new whether a new technique or more about the vessel that you are modeling is what makes this hobby so fascinating.
Roger
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Roger Pellett got a reaction from dgbot in SS Stephen Hopkins by schooner - FINISHED - BlueJacket Shipcrafters - Liberty Ship
Learning something new whether a new technique or more about the vessel that you are modeling is what makes this hobby so fascinating.
Roger
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Roger Pellett got a reaction from schooner in SS Stephen Hopkins by schooner - FINISHED - BlueJacket Shipcrafters - Liberty Ship
Learning something new whether a new technique or more about the vessel that you are modeling is what makes this hobby so fascinating.
Roger
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Roger Pellett got a reaction from cog in SS Stephen Hopkins by schooner - FINISHED - BlueJacket Shipcrafters - Liberty Ship
Learning something new whether a new technique or more about the vessel that you are modeling is what makes this hobby so fascinating.
Roger
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Roger Pellett got a reaction from Martin W in SS Kaiser Wilhelm der Grosse 1897 by Mirabell61 - FINISHED - scale 1:144 - POF - first German four stacker of the Norddeutscher Lloyd line
Nils,
If you don't mind using plastic sheet you might consider using the model boat that you bought to vacuum form the boats. I would led recommend forming them in port and starboard halves. You would have to cut your model longitudinally in half. When the formed halves are cut from the flat sheet you have a nice little flange on each side to glue together that can then be shaped for the keel. The thwarts and air tank top can then be cut out as sa third piece and glued into the top.with your abilities, I'm sure that you would have no trouble mass producing them.
If you have not used vacuum forming it is simple, and foolproof. A shop vacuum provides plenty of suction. You can produce a wonderfully light delicate boat that will look even better than the model that you bought.
Roger
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Roger Pellett got a reaction from Mirabell61 in SS Kaiser Wilhelm der Grosse 1897 by Mirabell61 - FINISHED - scale 1:144 - POF - first German four stacker of the Norddeutscher Lloyd line
Nils,
If you don't mind using plastic sheet you might consider using the model boat that you bought to vacuum form the boats. I would led recommend forming them in port and starboard halves. You would have to cut your model longitudinally in half. When the formed halves are cut from the flat sheet you have a nice little flange on each side to glue together that can then be shaped for the keel. The thwarts and air tank top can then be cut out as sa third piece and glued into the top.with your abilities, I'm sure that you would have no trouble mass producing them.
If you have not used vacuum forming it is simple, and foolproof. A shop vacuum provides plenty of suction. You can produce a wonderfully light delicate boat that will look even better than the model that you bought.
Roger
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Roger Pellett got a reaction from Scottish Guy in For Beginners -- A Cautionary Tale
Many years ago, I had a friend who was interested in building a model ship. I suggested the Model Shipways Virginia Pilot Boat model which he purchased. As we worked together we often had lunch together and I would always ask how he was coming and offer help. His answer was always "I got it out but was afraid that I would mess it up." I suspect that upon his too early death, the kit was thrown out.
My advice to beginners would therefore be a little different:
Get busy and build the model before you lose interest! Your first model will not be a collector's item. You will make mistakes. Hopefully your second model will be better than your first. Today, as I build models, I still make mistakes, and as the model goes forward, I tend to remember them more than the successes, but after the model has been sitting for a while in its case in my study, I look at it and realize, wow! This is a good representation of XXXXX.
This is a difficult craft and not moving ahead until you achieve perfection, will prevent you from mastering it.
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 reacted to schooner in SS Stephen Hopkins by schooner - FINISHED - BlueJacket Shipcrafters - Liberty Ship
As to when this rudder design was adopted, this pix shows the Liberty F.A.C. Muhlenberg with a contravene rudder prior to her June 1942 launching which was just two months after the Hopkins' launching so I think it's probable the Hopkins had one too.
I always like to learn something new.
Tim
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Roger Pellett got a reaction from Elijah in SS Stephen Hopkins by schooner - FINISHED - BlueJacket Shipcrafters - Liberty Ship
Nope, the offset rudder is an intentional design feature called a contravene rudder. It is a form of contravene propeller, a term described in the SNAME glossary of maritime terms. Any water behind the propeller moving faster than the undisturbed water surrounding the ship contains kinetic energy and in addition to steering the ship this rudder's job is to maximize recovery of this kinetic energy by straightening the flow.
A photo of the American Victory in dry dock shows this same rudder feature. This photo was published in the NRJ several years ago.
In PN Thomas's British Tramps, Volume I general arrangement drawings of Liberty ships do not indicate this feature. In fact the Liberty's British predessor appears to have a single plate rudder. Thomas also says that a number of Liberty ship rudders failed and the rudder was redesigned late in the war. So the American Liberty's rudders were redesigned. The question is whether this feature was incorporated when the Americans revised the British design or was it added when the rudders were revised late in the war.
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 WackoWolf in SS Stephen Hopkins by schooner - FINISHED - BlueJacket Shipcrafters - Liberty Ship
Nope, the offset rudder is an intentional design feature called a contravene rudder. It is a form of contravene propeller, a term described in the SNAME glossary of maritime terms. Any water behind the propeller moving faster than the undisturbed water surrounding the ship contains kinetic energy and in addition to steering the ship this rudder's job is to maximize recovery of this kinetic energy by straightening the flow.
A photo of the American Victory in dry dock shows this same rudder feature. This photo was published in the NRJ several years ago.
In PN Thomas's British Tramps, Volume I general arrangement drawings of Liberty ships do not indicate this feature. In fact the Liberty's British predessor appears to have a single plate rudder. Thomas also says that a number of Liberty ship rudders failed and the rudder was redesigned late in the war. So the American Liberty's rudders were redesigned. The question is whether this feature was incorporated when the Americans revised the British design or was it added when the rudders were revised late in the war.
Roger Pellett
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Roger Pellett got a reaction from jud in SS Stephen Hopkins by schooner - FINISHED - BlueJacket Shipcrafters - Liberty Ship
Nope, the offset rudder is an intentional design feature called a contravene rudder. It is a form of contravene propeller, a term described in the SNAME glossary of maritime terms. Any water behind the propeller moving faster than the undisturbed water surrounding the ship contains kinetic energy and in addition to steering the ship this rudder's job is to maximize recovery of this kinetic energy by straightening the flow.
A photo of the American Victory in dry dock shows this same rudder feature. This photo was published in the NRJ several years ago.
In PN Thomas's British Tramps, Volume I general arrangement drawings of Liberty ships do not indicate this feature. In fact the Liberty's British predessor appears to have a single plate rudder. Thomas also says that a number of Liberty ship rudders failed and the rudder was redesigned late in the war. So the American Liberty's rudders were redesigned. The question is whether this feature was incorporated when the Americans revised the British design or was it added when the rudders were revised late in the war.
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 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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