“Limit of positive stability”的意思、由来-开放百科全书

The limit of positive stability (LPS) or angle of vanishing stability (AVS) is the angle from the vertical at which a boat will no longer stay upright but will capsize, becoming inverted, or turtled.^[1]^[2]^[3]^[4]^[5]^[6]^[7]

For example, if a boat with an LPS of 120 degrees rolls past this point, i.e. its mast is already at an angle of 30 degrees below the water, it will continue to roll and be completely upside down in the water.^[4] Except for dinghy sailboats and multihulls, most larger sailboats (monohull keelboats) have lead or other heavy materials in their keel at the bottom of their hulls to keep them from capsizing or turtling.

The LPS was a part of the Offshore Racing Rules and is used to measure how stable or seaworthy a sailboat is. The modern offshore racing rules published by the International Sailing Federation may also use the measurement.

See also

Notes

1. ^{{cite web |url=http://setsail.com/evaluating-stability-and-capsize-risks-for-yachts/ |title=Evaluating Stability and Capsize Risks for Yachts |first1=Steve |last1=Dashew |publisher=setsail.com |date=8 January 2012 |accessdate=22 November 2013}}
2. ^{{cite news |url=http://articles.chicagotribune.com/2011-10-30/news/ct-met-mackinac-race-1030-20111030_1_capsized-wingnuts-boat |title=Report: Boat in deadly accident unfit for Mackinac race {{mdash}} Craft that capsized called too unstable for long competition in area prone to severe weather |date=30 October 2011 |first1=John |last1=Keilman |newspaper=Chicago Tribune |accessdate=22 November 2013}}
3. ^{{cite web|url=http://media.ussailing.org/AssetFactory.aspx?vid=16940 |title=Inquiry Into the Chicago yacht Club-Race to Mackinac Capsize and Fatalities |first1=Chuck |last1=Hawley |first2=John |last2=Rousmaniere |authorlink2=John Rousmaniere |first3=Ralph |last3=Naranjo |first4=Shiela |last4=McCurdy |date=18 October 2011 |accessdate=23 November 2011 |publisher=US Sailing |format=PDF |deadurl=yes |archiveurl=https://web.archive.org/web/20111111085204/http://media.ussailing.org/AssetFactory.aspx?vid=16940 |archivedate=11 November 2011 |df= }}
4. ^¹{{cite news |url=http://www.sailmagazine.com/cruising-news/sailing-accidents-lessons-learned |title=Sailing Accidents: Lessons Learned |first1=John |last1=Rousmaniere |date=13 September 2012 |accessdate=November 27, 2013 |newspaper=Sail}}
5. ^{{cite book|last=Rousmaniere |first1=John |authorlink1=John Rousmaniere |year=1980 |title=Fastnet, Force 10: The Deadliest Storm in the History of Modern Sailing |type=Paperback |pages=304 |publisher=W. W. Norton & Company (17 April 2000) |isbn=0393308650}} {{ISBN|978-0393308655}}
6. ^{{cite web |url=http://www.sailnet.com/forums/racing-articles/20646-revisiting-lessons-fastnet.html |first1=John |last1=Rousmaniere |date=January 2000 |title=Revisiting Lessons from the Fastnet |publisher=SailNet.com |accessdate=25 November 2013}}
7. ^{{cite web |title= 1979 Fastnet Race Inquiry |url= http://www.blur.se/images/fastnet-race-inquiry.pdf |website= Blur.se |publisher= Royal Yachting Association, Royal Ocean Racing Club |format=PDF |first1=Sir Hugh |last1=Forbes |first2= Sir Maurice |last2=Laing |first3= Lt. Col. James |last3=Myatt |year=1979 |accessdate= 23 November 2013}}