captain_crunch

Which designer should get credit for separating the rudder from the keel?

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Which designer should get credit for separating the rudder from the keel?

This question was the subject of debate in another thread.  The answer is Nathaniel Herreshoff with his 1891 design Dilemma.  He followed this up on a much larger scale in 1893 with two America's Cup defender candidates, Jubilee and Pilgrim; however, they were defeated in the defender trails.  The 1895 America's Cup was defended by another Nathaniel Herreshoff design, Defender, which had a conventional underbody with the rudder attached to the keel.  Nathaniel Herreshoff seemed to abandon the idea of the split underbody after that.

Dilemma

1891_Herreshoff_Dilemma_Figure.jpg

Dilemma

1891_Herreshoff_Dilemma_Lines.jpg

Jubilee

1893_Herreshoff_Jubilee_Profile.jpg

Pilgrim

 

 

1893_Herreshoff_Pilgrim_Profile.jpg

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After Nathaniel Herreshoff's experiments, the separation of the rudder from the keel was largely forgotten for larger boats; however, it did periodically reappear in smaller boats.  Examples include Francis Sweisguth's Star in 1910 and C. Raymond Hunt's "10" series.  The International 110 designed in 1939 continues to have several racing fleets across the country.  There was also experimentation in the smaller meter boat classes, such as Uffa Fox's Noroda of 1950.
 

Star

1910_Sweisguth_Star_Profile.png

International 110

1939_Hunt_110.jpg

Noroda

1950_fox_noroda.jpg

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Credit for the first offshore cruiser with the keel separate from the rudder should perhaps go to L. Francis Herreshoff for his 1946 design Marco Polo, but this design was an evolutionary dead end.  No other designer was inspired to follow his lead.  He did not take advantage of the configuration to reduce the keel to an efficient shape, and he did not repeat the configuration in any of his subsequent designs.  Some other of his designs did have a modest bite out of the keel forward of the rudder, such as Tioga of 1931.

 

Marco Polo

1946_herreshoff_marco_polo_profile.jpg

Tioga

1931_herreshoff_tioga_lines_600wide.jpg

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The actual progenitors of offshore sailboats wtih split underbodies might be Laurent Giles's Barchetta (A.K.A. Sopranino) of 1950 and Wendell Calkins's Legend of 1951.  I hesitate to include Sopranino in this category as she was just twenty feet long, but she was sailed across the Atlantic by Patrick Ellam and Colin Mudie in 1951, and John Guzzwell sailed a near sister, Trekka, around the world a few years later.  Legend had a length of 50 feet.  Under the command of her owner, Charles Ullman, she won the 1957 Transpac.  It is reported that Legend was banned from the next two Transpacs and was assigned a 24-hour time penalty when she was allowed to compete again.  Several sisters of Legend were produced as the Calkins 50, and a 40-foot version was also produced.  Both Sopranino and Legend were very light for their time and might be considered early Ultra Light Displacement Boats (ULDB).

Barchetta/Sopranino

1950_giles_barchetta_drawing.jpg

Barchetta/Sopranino

1950_giles_barchetta_photo.jpg

Legend

1951_calkins_legend_photo_600wide.jpg

Legend

1951_Calkins_Legend-Jan-1958-BW-768x1075.jpg

Trekka

1955_giles_trekka_iso_600wide.jpg

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Other early adopters of the split underbody were William Garden with Oceanus in 1957 and E. G. Van de Stadt with the Junior Holiday in 1954, Black Soo in 1957, and Pioneer 9 in 1959.  The Pioneer 9 may have been the first high-production-volume fiberglass ocean racer with this configuration.  Perhaps the first high-production-volume fiberglass ocean racer in the United States with this configuration was C. William Lapworth's Cal 40 of 1963.  The Cheoy Lee Lapworth 50 appeared in 1962, but only six were built.
 

Oceanus

1957_garden_oceanus.jpg

Holiday Junior

1954_van_de_stadt_junior_holiday.jpg

Black Soo

1957_van_de_stadt_black_soo.jpg

Pioneer 9

1959_van_de_stadt_pioneer_9_photo1.jpg

Cheoy Lee Lapworth 50

1962_lapworth_cheoy_lee_lapworth_50.jpg

Cal 40

1963_lapworth_cal_40_drawing3.jpg

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Perhaps bilge keelers should also be considered.  Arthur Robb's Bluebird of Thorne appeared in 1962, and Laurent Giles's Westerly Centaur appeared in 1969.  I have ignored centerboarders unless they had a substantial fixed keel, such as Nathaniel Herreshoff's Jubilee.
 

Bluebird of Thorne

1962_robb_bluebird_of_thorne_drawing_600wide.jpg

Westerly Centaur

1969_giles_westerly_centaur_26_drawing.jpg

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The split underbody configuration didn't become commonplace until the mid 1960s.  Michel Dufour used a split underbody for the Sylphe in 1964 and the Arpege in 1966, Bill Tripp used it for the Columbia 50 in 1965, Per Brohall used it for the Albin Viggen in 1966, and Dick Carter used it for Tina in 1966. 

Sylphe

1964_dufour_sylphe.jpg

Dufour Arpege

1966_dufour_arpege_drawing.jpg

Columbia 50

1965_tripp_columbia_50.jpg

Albin Viggen

1966_brohall_albin_viggen.jpg

Tina

1966_carter_tina_profile_600wide.jpg

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Sparkman & Stephens used the configuration in 1962 for the Rainbow 24.  They started using this configuration for their ocean racers in 1965 for Palawan III.  The first production ocean racer with this configuration from Sparkman & Stephens may have been the Swan 36 in 1967.  Their design for Intrepid in 1967 was the first successful America's Cup competitor with a rudder separated from the keel, sort of.

Rainbow 24 (1964 Weekender Version)

1962_s&s_rainbow_drawing_1964_weekender_version.jpg

Palawan III

1965_s&s_palawan_redo.JPG

Swan 36

1967_s&s_swan_36_drawing_600wide.gif

Intrepid

1967_s&s_intrepid_drawing_600wide.jpg

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Interesting.

I can see why the idea of the separate rudder was dropped after the first few attempts. In each of these designs, perhaps with the exception of the Star Class there are fundamental problems with the design. Look where the rudders are. Look at the planform shapes. Look at the size of the rudders. Look at that awful rudder on the Uffa Fox boat. DILEMA comes close but that rudder is pretty small. Same with JUBILEE and DEFENDER, really close but too small. Makes me wonder why, at that time, someone didn't say, "Let's make the rudder bigger."

 

If you want to see early, circa 1955, successful attempts at using a separate rudder on larger than dinks boats you should look at the work of Seattle's Ben Seaborn, designer of the Thunderbird Class sloop. Ben was getting it right. His clients at Boeing were coaching him on foil; shapes and he was the first designer I know of to use the percentage of chord method to lay out foil sections. Rawson 26 built in 1960. Very quick little boat.

 

The 50'er SEAFEVER was designed in 1956 and was very succesful with a seperate rudder much like the Calkins and Lapworth boats.

32652408378_f976dbe83a_b.jpgSeafair by robert perry, on Flickr

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^^ Thanks for pointing out the Thunderbird.  I have very little information on the work of Ben Seaborn.  I wonder if he did any split underbodies before the Thunderbird.

Thunderbird

1955_seaborn_thunderbird_drawing.jpg

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The Twelve Metre rule and the CCA rule penalized light displacement.  John Spenser's 1965 design Ragtime went in a very different direction and was perhaps the first ULDB.  Bill Lee noted this as his inspiration for Magic in 1970 and his first production design, the Santa Cruz 27, in 1974.  George Olson went in the same direction with the Moore 24 in 1972.
 

Ragtime

1965_spenser_ragtime_on_trailer_600wide.jpg

Moore 24

1972_olson_moore_24.jpg

Santa Cruz 27

1974_lee_santa_cruz_27_brochure_dwg.jpg

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Mr. Perry has pointed out a strong contender.  Ben Seaborn designed the Blanchard Knockabout Junior in 1934 and the Blanchard Knockabout Senior in 1935.

Blanchard Knockabout Junior

1934_seaborn_blanchard_knockabout_jr_drawing.jpg

Blanchard Knockabout Senior

1935_seaborn_blanchard_senior_knockabout_drawing.jpg

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Cruncher:

Google is your friend.

Yes, Seaborn was doing split appendage boats before the Thunderbird. He did the Sierra Class 191955 and that boat was extremely successful in the PNW. In 1956 he did the 50' SEA FEVER and sister ship HELENE.

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I have sailed both of those Blanchard boats. Good boats.

The Senior Knockabout uses the Star Class rudder and keel. This was an extremely successful PNW class for many years, well suited to out light air lake racing.

I think Seaborn gets overlooked because the PNW is a pretty isolated yachting area. He also died a tragic early death at his own hand. From time to time I think about the fact that Seaborn and Garden were working at the same time, a stone's throw from each other. One was totally on top of what made boats go while the other seem to struggle with those elements. I once asked Bill what he thought of Seaborn and he had very little to say. I took it that they were not friends.

31585690357_e9e052828c_b.jpgSEA FEVER by robert perry, on Flickr

 

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I read a claim that the early Herreshoff attempt were undone by the rule makers. Or was that his catamaran?

Uffa Fox is often claimed to have made the first offshore separation with the rather odd Huff of Arklow, in 1951.

 

huff.jpg

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52 minutes ago, Mr. Ed said:

I read a claim that the early Herreshoff attempt were undone by the rule makers. Or was that his catamaran?

Uffa Fox is often claimed to have made the first offshore separation with the rather odd Huff of Arklow, in 1951.

 

huff.jpg

Huff of Arklow is an interesting boat with an interesting story.  It's natural to think that Uffa Fox would have extended his experience with smaller boats and the six meter class to larger offshore racers.

 

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I have a 1946 book by Yachting Magazine titled "Your New Boat" that features two small cruisers with split underbodies.  One was drawn by Frederick Geiger and the other is by Donald Abbott.  I'm not saying these are the boats that started the trend.  I'm just saying the idea was being tossed around.

Knockabout by Frederick Geiger

1946_geiger_knockabout_800wide.jpg

Caller by Donald Abbott

1946_abbott_caller_800wide.jpg

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Two boats that deserve mention are Laurent Giles's 1947 design Myth of Malham and his 1950 design Gulvain.  Neither had a split underbody, but they introduced several trends that are associated with ULDBs.

- Light Displacement

- Long Waterline/Short Overhangs

- Vertical or Reverse Transom

- Flat or Reverse Shear

Myth of Malham

1947_giles_myth_of_malham_600wide.jpg

Gulvain

1950_giles_gulvain_600wide.jpg

1950_giles_gulvain_photo.jpeg.jpg

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33 minutes ago, monsoon said:

I'm going with the Egyptians, 1000 BC.  Twin rudders! Separate from keel! 

ec2bcb958155febe4b351689574ba596.jpg

 

Most innovations follow a long long line back into history; I'd be very surprised if Herreshoff's 1890s boat was the first to have the rudder separate from the keel..... obviously small boats with transom-hung rudders have been around a long time before that.

The question is going to be, what documentation exists on the matter? Once you go back past the New Steel Navy, or Disraeli, or however you want to label the late industrial revolution era,  yacht design specifics get pretty hard to pin down.

FB- Doug

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I believe TWINKLE and SPARKLE (two of my favorite boats) also had split keel/rudder configurations. They were pretty early 1940/50’s?

(On another note, so many innovations in sailing were introduced by two fellows with the last name Herreshoff!)

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I think we will never know who separated the rudder from the keel first. Too many iterations and like so many things in history, the person given credit is seldom the real originator.

Herreshoff probably gets the credit because he had the small advantage of owning a huge boat building company and he had the money to play with.

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11 minutes ago, kimbottles said:

I believe TWINKLE and SPARKLE (two of my favorite boats) also had split keel/rudder configurations. They were pretty early 1940/50’s?

(On another note, so many innovations in sailing were introduced by two fellows with the last name Herreshoff!)

Ben Seaborn's 1947 design Sparkle had a conventional underbody.  His 1949 design Twinkle had a split underbody.

Sparkle

1947_seaborn_sparkle_photo.png

1947_seaborn_sparkle_profile.jpg

1947_seaborn_sparkle_sailplan.jpg

Twinkle

1949_seaborn_twinkle.jpg

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Perhaps the question should be what design inspired subsequent designs.  I find myself leaning towards Laurent Giles with Barchetta/Sopranino.  It isn't just that she had a split underbody.  It's that the underbody was efficient and so was the rest of the hull.  In the book "Laurent Giles and His Yacht Designs" by Adrian Lee and Ruby Philpott, model yachts are claimed as the inspiration for Barchetta/Sopranino.  It is also stated that she had a trapeze and was designed to plane.  This was basically a 1950 version of the Wylie Wabbit.  The text from the book appears in the figures below.  She got a lot of publicity at the time, and certainly most other sailboat designers would have known about her.

 

1950_giles_barchetta_pg1_800wide.jpg

1950_giles_barchetta_pg2_800wide.jpeg

1950_giles_barchetta_pg3_800wide.jpg

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Just worth mentioning, maybe...... a big step backwards?

Gypsy Moth IV, design credit assigned to Illingworth/Primrose but from my reading of the story, Chichester back-seat-drove the building of the boat so much that it's really not theirs.

images?q=tbn:ANd9GcR9-cTqZf-IopN7wpgXzgQ

The reason I mention it: the original design had a rather full fin and a seperated rudder, which Chichester loathed and absolutely refused to accept; so he just had the builder (Camper & NIcholson) fill in the area between the keel and rudder. He then loathed her steering characteristics, and bitched about it on almost every other page of his account. I also wonder if the added volume down low made her more tender, which he also complained about.

All that aside, a great accomplishment (especially if you take the design/build squabbles as a lesson in "how not to") and a great story.

GypsyMothDM2805_468x320.jpg

FB- Doug

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^^ Gipsy Moth IV is a beloved boat that actually was deeply flawed, and a lot of this was due to the conflicting visions of Francis Chichester and Gipsy Moth's designer John Illingworth.  A major design objective was to have a voyage time to Australia that was competitive with the speed of the clipper ships.  Chichester wanted a smaller boat, but Illingworth saw that a longer boat was the only way to achieve the required speed.  Chichester set an upper bound for the size of the sails, which required that the hull be lighter and narrower than she might otherwise have been.  Gipsy Moth was tender and hobby horsed.  She was difficult to steer, and impossible to steer in reverse.  Chichester actually had naval architect Warwick Hood make some modifications during his stopover in Sydney.  It is interesting to contrast John Illingworth's design for Gipsy Moth IV with Robert Clark's design for Gipsy Moth V.  Gipsy Moth V has a longer waterline, and the rig is a staysail ketch, which allowed for the individual sails to be reduced in size.

Gipsy Moth IV

Gipsy_Moth_iso2.jpg

Gipsy Moth V

gypsy_moth_v.jpg

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Maybe the real question should be, who put the rudder and keel together? They had been separate on ocean going boats for millenia: viking longboats, Polynesian canoes, the Egyptian example, etc. The question you are asking is, "Who rediscovered the separate rudder?". Crediting it or the catamaran to N.H. reminds me of Lee Iacoca saying "Chrysler invented the minivan" completely ignoring decades of VWs. There is very little new in yacht design that weren't tried or used in antiquity. Foils is about the only thing I can think of. 

The answer to why the rudders were so small  - like many features of yacht design - may be in materials science. It's hard to build a 8:1 aspect spade rudder for a heavy boat with trees. Also perhaps why foils haven't been tried until recently. Carbon fiber is a game changer.

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44 minutes ago, captain_crunch said:

 

Ben Seaborn's 1947 design Sparkle had a conventional underbody.  His 1949 design Twinkle had a split underbody.

 

Twinkle

1949_seaborn_twinkle.jpg

perry13__13.2558.650x451.1.jpg

 

Beauty is as beauty does. 

 

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9 minutes ago, DDW said:

Maybe the real question should be, who put the rudder and keel together? They had been separate on ocean going boats for millenia: viking longboats, Polynesian canoes, the Egyptian example, etc. The question you are asking is, "Who rediscovered the separate rudder?". Crediting it or the catamaran to N.H. reminds me of Lee Iacoca saying "Chrysler invented the minivan" completely ignoring decades of VWs. There is very little new in yacht design that weren't tried or used in antiquity. Foils is about the only thing I can think of. 

The answer to why the rudders were so small  - like many features of yacht design - may be in materials science. It's hard to build a 8:1 aspect spade rudder for a heavy boat with trees. Also perhaps why foils haven't been tried until recently. Carbon fiber is a game changer.

Good point!  Before they attached the rudder to the keel, they had to invent the keel.  To the best of my knowledge, ancient ships didn't have keels that were clearly distinct from the main body of the hull.  A region of deadwood aft of the main underwater volume eventually evolved, and the rudder was attached to the aft end of this.  I couldn't tell you when the fin keel distinct from the main volume of the hull evolved.

 

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Not sure TWINKLE is a Seaborn design. Better check that. I seem to recall it being designed by a guy in California. I could be wrong. Kim will know. I have been talking to the owner about some changes to keel and rudder. My advice to him was,  "Leave it alone. Don't mess with a classic."

 

As to why small rudders:

We were doing high aspect deep and big spade rudders well before carbon was used. I have a walls full of them. Just takes a bigger stock. Of course carbon makes it easier to control the foil but it can be done in timber or grp. Not a problem.

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Very interesting thread and a good read - some things seem so obvious now.  So in regards to the rudder why were they almost always so round in addition to being small? The roundness reduces area and has no benefit that I can see. 

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17 minutes ago, captain_crunch said:

Good point!  Before they attached the rudder to the keel, they had to invent the keel.  To the best of my knowledge, ancient ships didn't have keels that were clearly distinct from the main body of the hull.  A region of deadwood aft of the main underwater volume eventually evolved, and the rudder was attached to the aft end of this.  I couldn't tell you when the fin keel distinct from the main volume of the hull evolved.

 

I think we're all surprised by how Herreshoff's fin keels were just slab sided, but it seems that the modern understanding of lift from aerofoil sections didn't really begin until the 1900s: and the Joukowski theory. Before that it was assumed that all the lift came from the increased pressure under the foil - what we think of as a stalled condition. I could pretend I know this stuff, but of course I don't, having just nicked it from this:

http://acversailles.free.fr/documentation/08~Documentation_Generale_M_Suire/Aerodynamique/Theorie/Highlights_from_the_history_of_airfoil_develoment.pdf

 

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^^ Thanks for the link.  The article shows a photo of the Variable Density Wind Tunnel at NASA Langley Research Center.  It dates from 1922 when Langley was a NACA facility.  I presently work at NASA Langley.  I previously worked at Newport News Shipbuilding, which actually built the wind tunnel.  The wind tunnel has long been retired, but it continues to serve as a garden ornament on the Langley campus.

 

naca_wind_tunnel.JPG

wind_tunnel_on_railcar.jpg

wind_tunnel_garden_ornament.jpg

wind_tunnel_plaque.jpg

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I think on the old ships the "keel" was part of the boat's structure. It had to run all the way aft. When ships got to a size where a side steering oar was no longer practical they came up with the natural solution and hung the rudder on the end of the keel. It was easy to support that way. Just my theory.

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5 hours ago, captain_crunch said:

 Uffa Fox's Noroda of 1950.
 

1950_fox_noroda.jpg

How could anyone look at that and think "Yep - looks right".

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14 minutes ago, Bob Perry said:

I think on the old ships the "keel" was part of the boat's structure. It had to run all the way aft. When ships got to a size where a side steering oar was no longer practical they came up with the natural solution and hung the rudder on the end of the keel. It was easy to support that way. Just my theory.

So the real question is who was the designer who first attached the rudder to the keel.

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1 minute ago, KC375 said:

So the real question is who was the designer who first attached the rudder to the keel.

 

Ronald Rudder?

 

 

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1 minute ago, KC375 said:

So the real question is who was the designer who first attached the rudder to the keel.

I think that was Zog.

Or maybe Rok did it earlier.

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I was thinking about the same thing regarding the stern mounted steering oar.

 If you look at ancient Egyptian riverboats, the stern mounted steering oar was standard, and quite separate from what little ballast the boats had. Some of them even had what you might call the earliest twin rudder designs. 

Here's a short video with a lot of great pics and even hieroglyphics of a whole bunch of detached rudders in the earliest wind propelled watercraft. 

 

 

 

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Fin keels came before separated rudders. There was an era of fin keels with attached rudders, especially in racing classes. Since these designers paid as much, or more, attention to wetted surface, the keels had fairly short chord length, leading to long skinny rudders on sharply raked rudder posts. We  look at these now and wonder "who though that was a good idea?" The geometry actually causes the rudder to exert an upward force on the water. That can't be fast. 

2018-12-30_1249.png

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Another person who might ought get some credit is Kenneth Davidson who established the towing tank at Stephens Institute, a big step in moving yacht design in the general direction from art to science.

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1 hour ago, Bob Perry said:

Not sure TWINKLE is a Seaborn design. Better check that. I seem to recall it being designed by a guy in California. I could be wrong. Kim will know. I have been talking to the owner about some changes to keel and rudder. My advice to him was,  "Leave it alone. Don't mess with a classic."

 

As to why small rudders:

We were doing high aspect deep and big spade rudders well before carbon was used. I have a walls full of them. Just takes a bigger stock. Of course carbon makes it easier to control the foil but it can be done in timber or grp. Not a problem.

Ben Seaborn designed Twinkle

Alex Irving designed Sparkle

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26 minutes ago, SloopJonB said:

How could anyone look at that and think "Yep - looks right".

Oh, I don't know - at least the weight's down low, but yes, the rudder is odd. Think how much more of a shock Uffa would have if he'd lived to see some of our new normals.

2016-11-02_9-24-55.jpg

 

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Who said that was normal?

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24 minutes ago, SloopJonB said:

Who said that was normal?

You mean you don't have horizontal canards? Crikey . . .

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Bluebird of Thorne was designed for Lord Riversdale who had himself, as the Hon R A Balfour, designed and built the 26’ Blue Bird in 1924. Twin rudders separated from the twin keels. A successful design, sailed round Britain and later Ireland.

Blue Bird.jpg

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Welcome. Gosh, that is an oddity eh? I wonder how it sailed. Bob, how would you interpet that almost circular hull? It looks like Balfour was 23 when he designed it.

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All roads lead back to Cruising Anarchy, and here's Arthur Robb's treatment of the same idea for Balfour

 

 
 

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2 hours ago, captain_crunch said:

Good point!  Before they attached the rudder to the keel, they had to invent the keel.  To the best of my knowledge, ancient ships didn't have keels that were clearly distinct from the main body of the hull.  A region of deadwood aft of the main underwater volume eventually evolved, and the rudder was attached to the aft end of this.  I couldn't tell you when the fin keel distinct from the main volume of the hull evolved.

 

Ballasted keel or lateral surface? Leeboards were in use in China by the 8th century, and in Europe in the 1500's. A leeboard and paddle rudder is effectively a fin keel and spade rudder. 

Sure you can do a deep narrow rudder with primitive materials, even concrete. But it isn't convenient, or strong, or as efficient in many ways. Today they are ubiquitous, but this is a recent development. The lift and drag advantages of high aspect ratio have been known since around 1910 or before, so why were they not adopted for sailboat rudders? There can be only three reasons: materials science, fad, or racing rules. I'm sure each played its part. They were deep and narrow on dinghies long before offshore boats, so the knowledge was there. 

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4 hours ago, captain_crunch said:

 

Ben Seaborn's 1947 design Sparkle had a conventional underbody.  His 1949 design Twinkle had a split underbody.

Sparkle

I believe Sparkle now has a separate rudder, maybe Brian and Guy added it during their restoration.

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1 hour ago, Mr. Ed said:

All roads lead back to Cruising Anarchy, and here's Arthur Robb's treatment of the same idea for Balfour

 

 
 

IIRC these boats were quite successful as cruisers, there is a Huon Pine one in Oz that spends some time down around here.

the big deal with the Bluebirds was the angle of incidence of the bilge keels, they were a series of designs to demonstrate the value of “toe in”, but I can’t recall the exact angles of the last boat.

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Boy,  I dunno about you guys,  but Legend....just...wow.   ( imagine making one with modern techniques )

Also the clear relation of the Moore to the early Giles designs is appreciated looking back & forth at them. (well,  to me anyway)

No mention of Uffa Fox's  Flying15 yet, so I'll do it - surely an early "sportboat"   

Great thread, thanks - Frankie's in some good company here.

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7 hours ago, Mr. Ed said:

I think we're all surprised by how Herreshoff's fin keels were just slab sided, but it seems that the modern understanding of lift from aerofoil sections didn't really begin until the 1900s: and the Joukowski theory. Before that it was assumed that all the lift came from the increased pressure under the foil - what we think of as a stalled condition. I could pretend I know this stuff, but of course I don't, having just nicked it from this:

http://acversailles.free.fr/documentation/08~Documentation_Generale_M_Suire/Aerodynamique/Theorie/Highlights_from_the_history_of_airfoil_develoment.pdf

 

That's a good point regarding the slab-sided nature of Herreshoff's keels.  The tendency is to focus on the planform and ignore the airfoil cross section.  So what is the ideal airfoil cross section for a keel or rudder?  I vaguely recall reading in Mr. Perry's book on yacht design that he generally opts for NACA sections with a 9% to 12% thickness to chord length ratio, and that practical considerations, such as the volume needed for ballast and tankage or the width needed for a rudder stock, play a large role in selecting the cross section.

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Interesting thread, thanks. 

But who says you need either? :huh:

 

 

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29 minutes ago, AlR said:

Many designers were using fin keels and spade rudders as far back as the 1890s, and probably earlier.  Herreshoff, Sibbick, Watson, Fife, all the big names.  Claiming someone in the 1950s started the trend is as dumb as some ahole claiming he designed the first performance cruiser in the 1970s.

https://www.facebook.com/charles.sibbick.interest.association

 

You really need some meds Jammer..

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7 hours ago, Great Red Shark said:

Boy,  I dunno about you guys,  but Legend....just...wow.   ( imagine making one with modern techniques )

Also the clear relation of the Moore to the early Giles designs is appreciated looking back & forth at them. (well,  to me anyway)

No mention of Uffa Fox's  Flying15 yet, so I'll do it - surely an early "sportboat"   

Great thread, thanks - Frankie's in some good company here.

A number of these boats participated in my inspiration to have Bob design FRANCIS LEE.

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16 hours ago, captain_crunch said:

After Nathaniel Herreshoff's experiments, the separation of the rudder from the keel was largely forgotten for larger boats; however, it did periodically reappear in smaller boats.  Examples include Francis Sweisguth's Star in 1910 and C. Raymond Hunt's "10" series.  The International 110 designed in 1939 continues to have several racing fleets across the country.  There was also experimentation in the smaller meter boat classes, such as Uffa Fox's Noroda of 1950.
 

Star

1910_Sweisguth_Star_Profile.png

International 110

1939_Hunt_110.jpg

Noroda

1950_fox_noroda.jpg

That’s actually not a 110 you have there, that’s the original concept, though not technically a 10 series boat, as it was the 225, built by Lawley and possibly Cape Cod Shupbuilding after they bought the 110, 210 and 225 related assets that Lawley had.  The 225 predates the 110 by about 4 years, and was basically unsuccessful because it turned out to be a bit too big to find the type of popularity that Hunt was seeking.  Luckily he persisted and graced us with the 110.  

 

There is one 225 left, and it’s a fabulous boat to sail.  Reaching with a blade jib the boat will easily do 15 kts.  Hunt had it right.   

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^^ Thank you for pointing that out.  There aren't many features to give away the scale.  I think this one might be an actual 110.

 

1939_hunt_110_drawing.jpg

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The rudder and keel on Uffa's boat looks awfully like that on a Flying Fifteen whch he designed in 1947.  Lovely boat (OK I'm biased as I've got one)  Dunno how on earth it gets upwind with its wacky keel, but it does quite nicely.

images?q=tbn:ANd9GcTa8G_AVXxBxB5EcRjtPOp

 

Bit of video https://vimeo.com/35522728

 

 

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9 hours ago, AlR said:

Many designers were using fin keels and spade rudders as far back as the 1890s, and probably earlier.  Herreshoff, Sibbick, Watson, Fife, all the big names.  Claiming someone in the 1950s started the trend is as dumb as some ahole claiming he designed the first performance cruiser in the 1970s.

https://www.facebook.com/charles.sibbick.interest.association

 

I'll defer to your obviously superior knowledge in this matter.

1895 William Fife Half-Rater

1895_fife_half_rater.jpg

1899 Charles Sibbick "Thelma"

1896_charles_sibbick_thelma.jpg

1899 Charles Sibbick "Bonafide"

1899_charles_sibbick_bonafide.jpg

1898 Linton Hope "Jewel" - Belfast Lough One Design, Class III

1905_linton_hope_jewel_class.jpg

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3 hours ago, captain_crunch said:

^^ Thank you for pointing that out.  There aren't many features to give away the scale.  I think this one might be an actual 110.

 

1939_hunt_110_drawing.jpg

Yes that’s a 110.  The keel and rudder are proportionally deeper on a 225.  

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17 hours ago, kimbottles said:

I believe Sparkle now has a separate rudder, maybe Brian and Guy added it during their restoration.

Yeah, that's right.  Sparkle was originally designed by Alex Irving with the rudder attached to the keel.  She was later rebuilt with a split underbody.

http://www.classicboat.co.uk/articles/restoring-sparkle/

 

sparkle_as_built.jpg

irving_sparkle_rebuilt.jpg

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There is also the 1953 Corsaire

cors_planis.JPG

Designed while France was licking its wars wounds to give people the opportunity to experience the sea.

Which opened the path for other designs like the Arpège (in a post above) and the muscadet below

da610edc7e30d652048182fb43deb37f.jpg

In the 70s, long keelers were discarded here, so much that in the 1980s money was raised to save the old gaffers for historic purposes. Most French sailors have very little longkeel experience, I have a bit but that's because I like wooden boats.

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Bob Smith designer, 1961 Cascade 29, built in PDX, produced 350 of them, pretty modern looking, with his signature curved bow profile

CASCADE 29 drawing

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Thomas Armstrong has a good blog post at the following link about the influence of Laurent Giles's Sopranino on Ben Seaborn's Thunderbird.  

http://70point8percent.blogspot.com/2008/11/minimalist-cruising-part-six-sisters.html

Question: Did Laurent Giles' Sopranino and Myth of Malham give birth to Ben Seaborn's Sierra and then the Thunderbird? I think it's possible,at least in part. Look closely.  Especially at the drawings.

Steve Bunnell, who wrote about Seaborn in WoodenBoat #148 and the Thunderbird in #149, cites Myth, designed by the revered British designer J. Laurent Giles in collaboration with John Illingworth, as a major influence on Seattle based Seaborn's thinking postwar. New materials and techniques  developed during the war years were to allow new thinking and led to the development of light displacement racing cruising boats, "big  dinghies" with a cabin.

That was also the thinking of Patrick Ellam, sailing out of Brightlingsea, when he approached Laurent Giles to design a craft to criteria he'd arrived at through  experimental voyages in his Theta, essentially a decked over sailing canoe with enough room for two which he sailed across the English channel at least four times.. He was quite surprised at Giles immediate acceptance of the project. The result was Sopranino, a name derived from a musical term for woodwinds indicating a smaller instrument achieving a higher octave ....Sopranino was really small, 19'6, with a bulb keel and reverse sheer and she definitely sounded a higher octave. Huge innovations cooked up by Ellam, Laurent Giles and John Illingworth, who consulted on the plans as drawn by Giles and is credited with being the father of modern ocean racing.  On september 6, 1951 Patrick set out to cross the Atlantic in her , with Colin Mudie, an employee of Laurent Giles and who had actually penned the plans for Sopranino, as crew. Sixteen months and 10,000 miles later they arrived in NY., effectively proving Patrick's theoretical musings. The voyage and experiment also resulted a must read little book, deserving of a niche in modern yacht evolution, appropriately titled Sopranino.

 By 1957 Ben Seaborn had absorbed the knowledge of light displacement experiments around the world yachting community and had several such designs under his belt. In that year he received a letter announcing a competition sponsored by the Douglas Fir Plywood Association. To be built in plywood, the design parameters for the competition were that it should be usable both for racing and cruising, it should sleep four, be capable of being built by reasonably skilled amateurs, be powered by an outboard  and outperform other boats in its class! Quite a list for an unfamiliar, new technology.  Initially Seaborn scoffed at this "challenge", as did most other designers receiving the notice letter.  Eventually, however, he took the bait and  consulted Ed Hoppen, a local boatbuilder intrigued with plywood construction. Their collaboration began and the result was the Thunderbird,which evolved from a previous design, the Sierra, a two person cruising boat. Needless to say the T'bird won the competition, and when completed surpassed all expectations in cruising ability, racing prowess and building techniques. Today a  universally applauded design, Seaborn and Hoppen had hit upon a building method in which the molds became permanent bulkheads. Seaborn himself was awed by his creation, never expecting the stability and speed he'd found in this  hard chine design. And she is accessible to the home builder. She was a hit. The class association reports that this is his most built design, with over1200 some odd registered boats. Plans are available for $50. from the Class Association! Reportedly this is a very fast racing yacht. Their PHRC rating has continued to move into more difficult ranges  over the years and they have been known to sail upwind with their spinnaker set and survive  60 to 70 mph winds, winning races when others had to retire. A Japanese woman cruised one across the Pacific, east to west, an inexperienced sailor sailed one from Puget Sound to Hawaii, one owner has made several voyages to Alaska. Typically, this Ben Seaborn design,like many of his  boats, has a very low windage cabin top and still manages to have an astounding amount of light in the interior.

Sadly, neither of these designers is still with us. Jack Laurent Giles was laid to rest in1969 and tragically, Ben Seaborn took his own life in January of 1960 at the age of 45, in part it's believed, because he felt himself a failure as a yacht designer. Jack passed away in 1969 after a long and successful career and his legacy lives on in his designs and in the design firm which bears his name. Ben's untimely death cut short a career which had already achieved greatness.

Both of these men were instrumental in planting the seeds which  have born much fruit in the evoluition of yacht design and ultimately leading to the light displacement racing yachts of today, from the exquisite little Mini Transat 650's to the "Open' series of maxi yachts which dominate transatlantic and around the world racing. They also had a hand in enabling small boat cruising sailors such as Roger Taylor and many others to trust  a light displacement boat to carry them safely across large oceans. All small boat sailors contemplating or making lengthy cruises owe them a debt of gratitude.

I have recently been very taken with the Thunderbird, for her speed, her seaworthiness , cruising ability and history. Found one, too, if I can figure out how to get her here.  I enquired on the junk rig yahoo goup about the feasability of rigging her junk and Arne Kverneland replied that she's an excellent candidate, but would suffer a slight loss of performance. OK!. Anyone who would like to help me get this boat from Rhode Island to PA, either by land or sea, write to me.

 

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There is a Jack Laurent Giles designed boat anchored right next to FRANCIS as I type this. They came in yesterday. I might go out and visit in 2019. Always liked his designs.......

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Perhaps the question should be who designed the first split underbody with airfoil shapes.

Many of the early split-underbody designs were not racing successes.  A likely factor in this is that they were slab-sided fins rather than airfoil shapes.

The following is a construction drawing for Sopranino and a closeup of the bulb at the bottom of the keel.  The bulb is not an airfoil.  It's a brick with rounded ends.

sopranino_construction_drawing.jpg

sopranino_construction_drawing_close-up.jpg

The following is a photo of Trekka's keel taken during a rebuild.  The intersection of the fin with the ballast bulb is a straight line.  The ballast bulb might have an airfoil shape.  Perhaps I misinterpreted the drawing.

trekka_keel_5.jpg

At the following link is a Sports Illustrated article about Wendell Calkins < https://www.si.com/vault/1963/03/04/606217/rollsroyce-luxury-on-the-high-seas >.  The article states the following regarding the Calkins 50.  "From Legend he took the keel, a hydrodynamically designed wing which, together with the rudder, gives C-50 the underwater profile of a swept-wing jet fighter sliced lengthwise."  If anyone has seen a Calkins 50 or Calkins 40 out of the water, it would be interesting to know if the keel is indeed an airfoil.  The drawing for the Calkins 50 seems to show that the keel is a hollow weldment with lead filling the lower half.  It definitely isn't a flat plate with a lead bulb bolted to the bottom.  

calkins_50_drawing.jpg

I looked around the Internet for information on Ben Seaborn's keel designs.  I couldn't draw any conclusions from photos of Thunderbirds, and the lines plan does not show the keel.  Other drawings show that the keel tapers so that it is wider at the bottom.  I did find mention that the keel is a casting.  It isn't a flat plate.  I'm sure there are people on this forum who could better describe the Thunderbrid's keel shape.

thunderbird_lines_without_keel.gif

Thunderbird-Specifications.jpg

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For comparison with the photo of Trekka's keel in the post above, here is Sopranino (or one of her sisters) out of the water.  The shape of the ballast bulb at the bottom of the keel is different.  Sopranino's ballast bulb has a torpedo shape.  Trekka's ballast bulb has a shape that looks like an airfoil.

 

sopranino_maybe.jpg

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On 12/31/2018 at 8:11 AM, eliboat said:

 

Yes that’s a 110.  The keel and rudder are proportionally deeper on a 225.  

Where is that 225 still sailing?

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