12-metre class
Encyclopedia
Sailing at the 1908 Summer Olympics - 12 metre class
The 12 Metre was a sailing event on the Sailing at the 1908 Summer Olympics originally programed in Ryde, but rescheduled for Hunter's Quay. Three races were scheduled...
, 1912
Sailing at the 1912 Summer Olympics - 12 metre class
The 12 Metre was a sailing event on the Sailing at the 1912 Summer Olympics program in Nynäshamn. Two races were scheduled plus eventual sail-off's...
and 1920
Sailing at the 1920 Summer Olympics
The sailing at the 1920 Summer Olympics consisted of a total of 16 sailing classes . Two of these classes finally did not have entries. For each class three races were scheduled from 7 July 1920 to 9 July 1920 of the coast of Ostend North Sea. On 10 July 1920 sail-off races could be held.Two...
but only few boats participated. The 12 Metre class boats are probably best known for their use from 1958 to 1987 in the America's Cup
America's Cup
The America’s Cup is a trophy awarded to the winner of the America's Cup match races between two yachts. One yacht, known as the defender, represents the yacht club that currently holds the America's Cup and the second yacht, known as the challenger, represents the yacht club that is challenging...
.
Rough equality between boats is ensured by requiring compliance with a formula that takes into account the length at the waterline
Waterline
The term "waterline" generally refers to the line where the hull of a ship meets the water surface. It is also the name of a special marking, also known as the national Load Line or Plimsoll Line, to be positioned amidships, that indicates the draft of the ship and the legal limit to which a ship...
, the girth (the measurement around the boat from one sideboard, under the keel
Keel
In boats and ships, keel can refer to either of two parts: a structural element, or a hydrodynamic element. These parts overlap. As the laying down of the keel is the initial step in construction of a ship, in British and American shipbuilding traditions the construction is dated from this event...
and then back over the top on the opposite side back to the original side) and the sail
Sail
A sail is any type of surface intended to move a vessel, vehicle or rotor by being placed in a wind—in essence a propulsion wing. Sails are used in sailing.-History of sails:...
area. The very carefully specified measurements are then entered into the formula, and the result must be less than or equal to 12 Metres - hence the name of the class. Designers are free to change any of these variables (as well as other details, such as the size of the rudder
Rudder
A rudder is a device used to steer a ship, boat, submarine, hovercraft, aircraft or other conveyance that moves through a medium . On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane...
and keel, etc.), with the understanding that for any change in any of the measured attributes, something else will have to be adjusted, in order to make the formula produce the required value.
The "12 Metre" in the class name does not refer to the actual length of the boats, which range from 65 to 75 feet (about 20 to 23 m) overall. They are all sloop
Sloop
A sloop is a sail boat with a fore-and-aft rig and a single mast farther forward than the mast of a cutter....
-rigged, with their masts typically being about 85 feet (26 m) tall. The "12 Metre" yachts are also referred to as "Twelves" or "12 Metres" or even "12s".
The Formula and Rules
The Formula and associated rules for designing and constructing 12 Metre yachts has been modified several times from inception in racing.The purpose of the Formula and rules was to encourage designer creativity to optimise designs to get the best overall performance when racing whilst maintaining competitive racing between the different designs. Although the Formula and Rules allowed some creativity they were also intended to be comprehensive enough to eliminate loop holes which could result in an extreme design which conformed to the 12 Metre rule but completely outclassed other contemporary designs on the race course. If the rules were considered to be too loose then it would discourage the building of new 12 Metre yachts for fear of a new boat being outclassed even before it was launched.
The Rules were typically updated in response to advances in areas such as material technology (e.g. metal masts versus wooden masts), design technology (e.g. use of the wind tunnel to design sails and sail/mast combinations, advances in fluid dynamics), and equipment (e.g. winch technology).
The Rule has four distinct periods:
First Rating Rule
where
-
= waterline lengthWaterline lengthThe Waterline length is a measurement of ships and boats. The term denotes the length of the vessel at the point where it sits in the water. It excludes the total length of the boat, such as features that are out of the water...
(LWL) -
= beamBeam (nautical)The beam of a ship is its width at the widest point. Generally speaking, the wider the beam of a ship , the more initial stability it has, at expense of reserve stability in the event of a capsize, where more energy is required to right the vessel from its inverted position... -
= chain girthChain girthChain girth is a measurement of a yacht hull.Chain girth is specified in some design rules to handicap or match the capabilities of sailing vessels of similar design such as the 12 metre boats... -
= difference between skin girthSkin girthSkin girth is a measurement of a yacht hull.Skin girth is specified in some design rules to handicap or match the capabilities of sailing vessels of similar design such as the 12 metre boats. Skin girth is measured by following the surface of the hull from a given elevation on the hull vertically...
and chain girthChain girthChain girth is a measurement of a yacht hull.Chain girth is specified in some design rules to handicap or match the capabilities of sailing vessels of similar design such as the 12 metre boats... -
= sail area -
= freeboardFreeboard (nautical)In sailing and boating, freeboardmeans the distance from the waterline to the upper deck level, measured at the lowest point of sheer where water can enter the boat or ship...
Second Rating Rule
Used from 1920–1933.
where
-
= waterline length (LWL) -
= chain girthChain girthChain girth is a measurement of a yacht hull.Chain girth is specified in some design rules to handicap or match the capabilities of sailing vessels of similar design such as the 12 metre boats... -
= difference between skin girthSkin girthSkin girth is a measurement of a yacht hull.Skin girth is specified in some design rules to handicap or match the capabilities of sailing vessels of similar design such as the 12 metre boats. Skin girth is measured by following the surface of the hull from a given elevation on the hull vertically...
and chain girthChain girthChain girth is a measurement of a yacht hull.Chain girth is specified in some design rules to handicap or match the capabilities of sailing vessels of similar design such as the 12 metre boats... -
= sail area -
= freeboard
Third Rating Rule, and, from 1956, the America's Cup Rule
Used from 1933 onwards:(International Twelve Metre Association):
where
-
= waterline length (LWL) -
= difference between skin girthSkin girthSkin girth is a measurement of a yacht hull.Skin girth is specified in some design rules to handicap or match the capabilities of sailing vessels of similar design such as the 12 metre boats. Skin girth is measured by following the surface of the hull from a given elevation on the hull vertically...
and chain girthChain girthChain girth is a measurement of a yacht hull.Chain girth is specified in some design rules to handicap or match the capabilities of sailing vessels of similar design such as the 12 metre boats... -
= sail area -
= freeboard
Associated with the formula is an extremely comprehensive set of rules. The rules can be classified into two main areas. Rules concerning safety and rules to ensure competitive racing. For example the maximum total area of all cockpits is specified to minimise the chance of a boat being swamped in rougher seas. Structural requirements are specified to ensure that strength is not sacrificed by the need to get weight low down in the keel. Materials are specified plus numerous other details concerning all aspects of the boat. The intention is to challenge designers but ensure competitive racing.
America's Cup
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
by a syndicate led by Henry Sears
Henry Sears
Henry Sears was an American commander and a commodore of the New York Yacht Club who competed in the America's Cup and discovered multiple species of marine fish.-Early life:...
, more economical vessels were desired to replace the huge and expensive J-class yacht
J-class yacht
The J-Class serves as a rating for large sailing yachts designed between 1930 and 1937. Reserved for a wealthy elite of yachtsmen, these boats were used to compete with the best sailing talents in three races of the America's Cup.-The 1930s:...
s that were raced in the 1930s; the 12 Metre class was selected.
In September 1956 a Royal Yacht Squadron
Royal Yacht Squadron
The Royal Yacht Squadron is the most prestigious yacht club in the United Kingdom and arguably the world. Its clubhouse is located in Cowes Castle on the Isle of Wight in the United Kingdom...
syndicate was formed to build a 12 Metre for the 1958 America's Cup
America's Cup
The America’s Cup is a trophy awarded to the winner of the America's Cup match races between two yachts. One yacht, known as the defender, represents the yacht club that currently holds the America's Cup and the second yacht, known as the challenger, represents the yacht club that is challenging...
. The UK challenger was selected based on model tank testing and David Boyd's second design was chosen. Sceptre was launched at the yard of Alexander Robertson and Sons Ltd (Yachtbuilders)
Alexander Robertson and Sons Ltd (Yachtbuilders)
Alexander Robertson started repairing boats in a small workshop at Sandbank, Argyll and Bute in 1876, and went on to become one of the foremost wooden boat builders on Scotland's River Clyde. The 'golden years' of Robertson's yard were in the early 1900s when they started building IYRU 12mR & 15mR...
on 2 April 1958, but lost to the New York Yacht Club yacht Columbia in September 1958. Sceptre is currently owned and raced by the Sceptre Preservation Society. Alexander Robertson and Sons Ltd (Yachtbuilders)
Alexander Robertson and Sons Ltd (Yachtbuilders)
Alexander Robertson started repairing boats in a small workshop at Sandbank, Argyll and Bute in 1876, and went on to become one of the foremost wooden boat builders on Scotland's River Clyde. The 'golden years' of Robertson's yard were in the early 1900s when they started building IYRU 12mR & 15mR...
also built two of the very early 12-Metres: Heatherbell (designer Thomas Glen-Coats, 1907), which represented Finland in the 1912 Summer Olympics; Cyra (designer Alfred Mylne
Alfred Mylne
Alfred Mylne was a Scottish yacht designer, born in Glasgow. He founded A Mylne & Co. in 1896.- Work :Alfred Mylne was apprenticed to the Scottish shipbuilders Napier, Shanks and Bell, and went on to work as a draftsman and apprentice to George Lennox Watson...
, 1909).
In 1987, use of the 12 Metre class was ended, switching to International America's Cup Class boats for the 1992 competition.
Famous 12 Metre Yachts
- Onawa (US 6) & Anitra (US 5) - The oldest American 12 Metre still intact.
- Vim: Designed in 1939 by Olin StephensOlin StephensOlin James Stephens II was an American yacht designer of the 20th century. Stephens was born in New York, but spent his summers with his brother Rod, learning to sail on the New England coast. He also attended the Massachusetts Institute of Technology for a term.Stephens' name had a long history...
who considered the possibilities given by every aspect of the rules and produced a very fast boat. Vim had numerous innovative features including a trim tab on the rudder, two-speed winches and a lighter mast made of duralamin (a form of aluminium used in the aircraft industry). Vim is considered a benchmark design which was continually refined over her racing career. In 1939 Vim came to the UK and won 19 races out of 28. The next generations of 12 Metres designed and built 20 years after Vim was launched still found Vim extremely difficult to beat in competition. - Sparkman & StephensSparkman & StephensSparkman & Stephens is a naval architecture and yacht brokerage firm with main offices on 5th Avenue in New York City, USA and offices in Ft. Lauderdale, Florida and Newport, Rhode Island, USA. The firm performs design and engineering of new vessels for pleasure, commercial, and military use....
designed five successful America's Cup defenders for the NYYC. The first was Columbia, winner of the 1958 Cup, followed by Constellation in 1964. IntrepidIntrepid (yacht)The Intrepid is a 12-metre class yacht which won the America's Cup in 1967 and again in 1970.-Design:Intrepid was designed by Olin Stephens, and was built of double-planked mahogany on white oak frames. She featured important innovations both above and below the waterline. The rudder was separated...
won the 1967 and 1970 ACs. CourageousCourageous (yacht)Courageous is a 12-metre class yacht. It was the third boat to win the America's Cup twice, in 1974 and 1977, after Intrepid in 1967 and 1970, and Columbia in 1899 and 1901. All three of these boats won for the NYYC and thus the United States...
won in 1974 and 1977 (skippered by Ted Hood in 1974 and Ted TurnerTed TurnerRobert Edward "Ted" Turner III is an American media mogul and philanthropist. As a businessman, he is known as founder of the cable news network CNN, the first dedicated 24-hour cable news channel. In addition, he founded WTBS, which pioneered the superstation concept in cable television...
in 1977). The last of the S&S designed twelves to win the America's Cup was Freedom in 1980. Both Intrepid and Courageous are still sailing and racing today in NewportNewport, Rhode IslandNewport is a city on Aquidneck Island in Newport County, Rhode Island, United States, about south of Providence. Known as a New England summer resort and for the famous Newport Mansions, it is the home of Salve Regina University and Naval Station Newport which houses the United States Naval War...
. Intrepid is available for charter whereas Courageous is privately owned. Columbia is available for charter in Newport. - Sceptre (K 17), the British challenger for the America’s Cup in 1958, is believed to be the only UK challenger still sailing in British waters.
- Australia IIAustralia IIAustralia II is the Australian 12-metre-class challenge racing yacht that was launched in 1982 and won the 1983 America's Cup for the Royal Perth Yacht Club...
, Alan BondAlan Bond (businessman)Alan Bond is an Australian businessman noted for his criminal convictions and high-profile business dealings, including what was at the time the biggest corporate collapse in Australian history. Bond was born in the Hammersmith district of London, England, and emigrated to Australia with his...
's famous winged keel boat that won the 1983 America's Cup1983 America's CupThe 1983 America's Cup was the occasion of the first winning challenge to the New York Yacht Club who had successfully defended the cup over a period of 132 years...
. The boat that ended the longest winning streak in all of sport. Designed by Ben LexcenBen LexcenBen Lexcen AM born Robert Miller was an Australian yachtsman and marine architect. He is famous for the winged keel design applied to Australia II which, in 1983, became the first non-American yacht to win the prestigious America's Cup in 132 years.-Early life:Born in the coastal town of...
, Australia II was one of the first racing yachts to use appendages on the keel, which allowed the yacht to point higher, sail faster and be quicker in stays. The keel design also allowed a reduction in weight in the keel which then allowed other beneficial changes in the measured dimensions which resulted in a yacht optimized for the conditions on the race course in Newport Rhode Island. - New ZealandKZ 7New Zealand "Kiwi Magic" was the America's Cup challenge boat sailed by Chris Dickson in the Louis Vuitton Cup Challenger series held in Gage Roads off Fremantle, Australia during the summer months of 1986 through 1987...
(KZ 7) "Kiwi Magic" Runner-up in 1987 Louis Vuitton Cup1987 Louis Vuitton CupThe 2nd Louis Vuitton Cup was held in Fremantle, Australia in 1987. The winner, Stars & Stripes, went on to challenge for and win the 1987 America's Cup.-The teams:...
, and the first Twelve Metre to be made from fibreglass. Nicknamed the "Plastic Fantastic". Skippered by Chris DicksonChris Dickson (sailor)Christopher Stuart Dickson, born 3 November 1961 in Auckland, is an internationally known sailor from New Zealand. He was world youth champion three years in succession and later became world match race champion three times... - Stars & Stripes 87Stars & Stripes 87Stars & Stripes 87 was the 12 Meter challenge boat sailed by Dennis Conner in his bid to reclaim the America’s Cup from the Royal Perth Yacht Club of Australia in 1987.-Design and Development:...
(US 55) Winner of the 1987 America's Cup1987 America's CupThe 1987 America's Cup was the twenty-seventh challenge for the America's Cup and the first time for 132 years that it had not been defended by the New York Yacht Club....
. The fastest heavy weather 12 Meter boat ever built.
In addition to design there are other factors which affect racing results. There are other 12 Metre designs which are fast boats but struggled to reach their full potential due to inadequate crewing or lack of preparation or bad luck or a combination of both.
In the America's Cup era it will always be a matter of debate but Vim, Intrepid, "Courageous", Australia II, and Stars and Stripes 87 are generally considered to be the best 12 Metres in terms of design excellence and performance on the race course.
Post America's Cup
12 Metre yachts were used for the last time in America’s Cup competition at the 1987 event held in Fremantle, Australia. 12 Metres continued to race together on a local basis but due to the high cost and without the impetus and prestige surrounding competition in the America’s Cup, no new boats have been built since 1987.The latter part of the 20th century saw a big revival in interest in classic yachts including 12 Metre yachts and particularly those of wooden construction. There were an increasing number of prestigious regattas in attractive locations such as the Mediterranean and the Caribbean. Also a more prosperous global economy prevailed and the result was an increasing number of restorations and racing of older ‘classic’ 12 Metres.
Potential restorers of older boats who wanted to race were potentially faced with a dilemma of whether to restore a boat to its original specification or make modifications to make an older design competitive with a newer design. For example a yacht designed under the First International Rule would have a wooden mast, gaff rig
Gaff rig
Gaff rig is a sailing rig in which the sail is four-cornered, fore-and-aft rigged, controlled at its peak and, usually, its entire head by a spar called the gaff...
and sails made of cotton whereas yachts designed under the Third International Rule, such as Vim, had a metal mast, Bermuda rig
Bermuda rig
The term Bermuda rig refers to a configuration of mast and rigging for a type of sailboat and is also known as a Marconi rig; this is the typical configuration for most modern sailboats...
and sails made from Dacron.
To encourage participation in racing and also encourage restoration which remained true to the spirit of the original design, the 12 Metre class association introduced a handicapping system to allow 12 Metres of all ages to race together on a more equal footing. The basis is a handicap applied to each boat according to the ‘era’ of its design to encourage owners to restore older boats and participate in exciting and sociable racing.
A 12 Metre is classified as belonging to one of three periods. Each Period is defined as a range of dates which coincided with a particular type of keel or rudder design becoming widespread.
Division A:- Also called Grand Prix, this subclass starts when winged keels became the norm. It covers all yachts built with winged keels and all yachts constructed after 1983. Australia II
Australia II
Australia II is the Australian 12-metre-class challenge racing yacht that was launched in 1982 and won the 1983 America's Cup for the Royal Perth Yacht Club...
was the first wing keeled 12 Metre and, despite being constructed before 1984. USA (US 61), also fits into this category, even though its keel structure is different from the standard winged keel of the class. It is also the only 12 Metre to have a "canard" or rudder mounted forward of the keel.
Division B (Modern):- Starts when a skeg
Skeg
A skeg is a sternward extension of the keel of boats and ships which have a rudder mounted on the centre line. The term also applies to the lowest point on an outboard motor or the outdrive of an inboard/outboard...
mounted rudder separated from the keel became the norm. It includes all 12 Metres built during the period 1968 - 1983. Intrepid
Intrepid (yacht)
The Intrepid is a 12-metre class yacht which won the America's Cup in 1967 and again in 1970.-Design:Intrepid was designed by Olin Stephens, and was built of double-planked mahogany on white oak frames. She featured important innovations both above and below the waterline. The rudder was separated...
is considered the first Modern even though it was built in 1967 since it was the first 12 Metre to use a skeg mounted rudder. It excludes Australia II
Australia II
Australia II is the Australian 12-metre-class challenge racing yacht that was launched in 1982 and won the 1983 America's Cup for the Royal Perth Yacht Club...
built in 1982 which is in Period A due to its winged keel design.
Division C (Classic):- All other 12 Metre class yachts built before 1968 but excluding Intrepid
Intrepid (yacht)
The Intrepid is a 12-metre class yacht which won the America's Cup in 1967 and again in 1970.-Design:Intrepid was designed by Olin Stephens, and was built of double-planked mahogany on white oak frames. She featured important innovations both above and below the waterline. The rudder was separated...
which is in Period B by virtue of its skeg mounted rudder design. Divisions D (Vintage)& E (Antique)are the remaining 2 Divisions based on the year of construction including Antique (most of which are in fact gaff rigged). Older sloop-rigged yachts like Vim and Onawa fit into the Vintage category, yavhts like Erna Signe belong to the Antique division. In the early 21st century interest in ownership and restoration of 12 Metres was such that specialist restoration companies would speculatively locate old boats under threat of destruction and publicize the availability in order to attract the funding for a full restoration .
External links
- The International Twelve Metre Association (ITMA)
- Trivia 12 Metre Restoration: 12 Metre yachts built the world wide
- History of 12 Metre Class and list of all US 12 Metre yachts built
- Sparkman & Stephens: The Twelves (Technical explanation)
- http://www.columbiatrading.com/cgi-bin/columbia/30590.html
- http://www.sceptrepreservation.co.uk/3.html