Universal Rule
Encyclopedia
The Universal Rule determined a yacht
s eligibility to race in the America's Cup
from 1914 to 1937. Ships built according to the rule reached their peak in the large J-class yacht
s.
Before 1914 the Seawanhaka Rule
was used, and after 1937 smaller boats were desirable, and so the International Rule regained its popularity and became the standard. The 6, 8 and 12 Metre Classes were the most popular and the latter used for the America's Cup until 1987, the last year the America's Cup was sailed in 12-meter yachts.
Yacht designer
Nathanael Herreshoff
devised the rule in 1903. Herreshoff had designed winning America's Cup yachts which fully exploited the Seawanhaka rule, which was based only on a yachts waterline length and sail area, to create narrow boats with long overhangs. This reached its peak with Reliance
, the defender of the 1903 America's Cup, which was described as a "racing freak", suitable only for certain conditions. This prompted Herreshoff to propose a rule which also took into account the displacement of the boat.
Variables:
The numerator contains a yacht's speed giving elements, length and sail area, while the retarding quantity of displacement is in the denominator. Also the result will be dimensionally correct, R will be a linear unit of length (such as feet or meters).
The listing for single mast boats, namely classes I through S.
There were multi-mast classes too, running Class A to Class H.
Yacht
A yacht is a recreational boat or ship. The term originated from the Dutch Jacht meaning "hunt". It was originally defined as a light fast sailing vessel used by the Dutch navy to pursue pirates and other transgressors around and into the shallow waters of the Low Countries...
s eligibility to race 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...
from 1914 to 1937. Ships built according to the rule reached their peak in the large 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.
Before 1914 the Seawanhaka Rule
Seawanhaka Corinthian Yacht Club
The Seawanhaka Corinthian Yacht Club is one of the oldest yacht clubs in the Western Hemisphere , located in Oyster Bay, New York, with access to Long Island Sound.-History:...
was used, and after 1937 smaller boats were desirable, and so the International Rule regained its popularity and became the standard. The 6, 8 and 12 Metre Classes were the most popular and the latter used for the America's Cup until 1987, the last year the America's Cup was sailed in 12-meter yachts.
Yacht designer
Naval architecture
Naval architecture is an engineering discipline dealing with the design, construction, maintenance and operation of marine vessels and structures. Naval architecture involves basic and applied research, design, development, design evaluation and calculations during all stages of the life of a...
Nathanael Herreshoff
Nathanael Herreshoff
Nathanael Greene Herreshoff I , was an American naval architect-mechanical engineer. "Captain Nat," as he was known, revolutionized yacht design, and produced a succession of undefeated America's Cup defenders between 1893–1920....
devised the rule in 1903. Herreshoff had designed winning America's Cup yachts which fully exploited the Seawanhaka rule, which was based only on a yachts waterline length and sail area, to create narrow boats with long overhangs. This reached its peak with Reliance
Reliance (yacht)
Reliance was the 1903 America's Cup defender, the fourth America's Cup defender from the famous designer Nat Herreshoff, and reportedly the largest gaff-rigged cutter ever built....
, the defender of the 1903 America's Cup, which was described as a "racing freak", suitable only for certain conditions. This prompted Herreshoff to propose a rule which also took into account the displacement of the boat.
Universal Rule formula
Mathematically, the Universal Rule formula was:Variables:
- L - Boat length
- S - Sail area
- D - Displacement
- R - Rating
The numerator contains a yacht's speed giving elements, length and sail area, while the retarding quantity of displacement is in the denominator. Also the result will be dimensionally correct, R will be a linear unit of length (such as feet or meters).
The listing for single mast boats, namely classes I through S.
- Class I: Rating = 88 feet
- Class J: Rating = 76 feet
- Class K: Rating = 65 feet
- Class L: Rating = 55 feet
- Class M: Rating = 46 feet
- Class N: Rating = 38 feet
- Class P: Rating = 31 feet
- Class Q: Rating = 25 feet
- Class R: Rating = 20 feet
- Class S: Rating = 17 feet
There were multi-mast classes too, running Class A to Class H.