Polymatroid: Difference between revisions
en>AK456 m WP:DPL |
en>Anonash Changed the definitions a bit |
||
Line 1: | Line 1: | ||
The '''Universal Rule''' determined a [[yacht]]'s eligibility to race in the [[America's Cup]] from 1914 to 1937. Boats built according to the rule reached their peak in the large [[J-class yacht]]s. | |||
Before 1914, the [[Seawanhaka Corinthian Yacht Club|Seawanhaka Rule]] was used, and after 1937 smaller boats were desirable, and so the [[International Rule (sailing)|International Rule]] regained its popularity and became the standard. The 6, 8 and 12 Metre Classes were the most popular and the latter was used for the America's Cup until 1987, the last year the America's Cup was sailed in 12-meter yachts. | |||
[[Naval architecture|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 yacht's waterline length and sail area, to create narrow boats with long overhangs. This reached its peak with ''[[Reliance (yacht)|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.<ref>[http://www.universalrule.com/index.php?page=3 universalrule.com ''History of the Universal Rule of Measurement'']</ref> | |||
==Universal Rule formula== | |||
Mathematically, the '''Universal Rule''' formula was: <math>R=\frac {0.2 \cdot L \cdot \sqrt{S}} {\sqrt[3]{D}}</math><ref>{{cite book|title=Elements of Yacht Design|author=Norman L. Skene|year=1904|publisher=The Rudder publishing company|url=http://books.google.com/books?id=V8TFHPwbgNgC&pg=PA146|page=146 | isbn=978-1-57409-134-2}}</ref> | |||
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). Sailing craft are thus rated when their <math>R</math> rating falls within a certain range. J-Class boats, for example, are any single masted craft with an <math>R</math> between 65 and 76 feet. | |||
The listing for single mast boats, namely classes I through S. | |||
*Class I: Rating = 76- 88 feet | |||
*Class J: Rating = 65 - 76 feet | |||
*Class K: Rating = 55 - 65 feet | |||
*Class L: Rating = 46 - 55 feet | |||
*Class M: Rating = 38 - 46 feet | |||
*Class N: Rating = 31 - 38 feet | |||
*Class P: Rating = 25 - 31 feet | |||
*Class Q: Rating = 20 - 25 feet | |||
*Class R: Rating = 17- 20 feet | |||
*Class S: Rating = 0 - 17 feet | |||
There were multi-mast classes too, running Class A to Class H. | |||
<references/> | |||
{{Yacht handicapping rules}} | |||
[[Category:Sailing rules and handicapping]] |
Revision as of 23:42, 10 April 2013
The Universal Rule determined a yacht's eligibility to race in the America's Cup from 1914 to 1937. Boats built according to the rule reached their peak in the large J-class yachts. 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 was 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 yacht's 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.[1]
Universal Rule formula
Mathematically, the Universal Rule formula was: [2]
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). Sailing craft are thus rated when their rating falls within a certain range. J-Class boats, for example, are any single masted craft with an between 65 and 76 feet.
The listing for single mast boats, namely classes I through S.
- Class I: Rating = 76- 88 feet
- Class J: Rating = 65 - 76 feet
- Class K: Rating = 55 - 65 feet
- Class L: Rating = 46 - 55 feet
- Class M: Rating = 38 - 46 feet
- Class N: Rating = 31 - 38 feet
- Class P: Rating = 25 - 31 feet
- Class Q: Rating = 20 - 25 feet
- Class R: Rating = 17- 20 feet
- Class S: Rating = 0 - 17 feet
There were multi-mast classes too, running Class A to Class H.
- ↑ universalrule.com History of the Universal Rule of Measurement
- ↑ 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.
My blog: http://www.primaboinca.com/view_profile.php?userid=5889534