Cunningham straightener
The Cunningham straightener (also luff straightener, Cunningham-Hole or Cunningham-Kausch ), or Cunningham for short , is a trim device for sailing boats . It is used to tension or loosen the mainsail immediately after the luff . The tensioning results in a flat sail profile and a shift of the sail belly forward; the slacking off causes the opposite - bulbous sail profile, displacement of the sail belly backwards. The Cunningham straightener should contribute to the optimal trim of the sail and thus to a high speed.
application
Rule of thumb for using the Cunningham straightener is: In stronger winds or on close -to-wind courses (the wind comes diagonally from the front), you should push through (tighten) the Cunningham straightener; in light wind, or on half-wind courses (the wind comes from the side), spacing courses (the wind comes from diagonally behind) or pre-wind courses (the wind comes directly from behind), the Cunningham straightener should be lowered (eased ) become. On the other hand, the practical use of the Cunningham stretcher is also called into question, since the effect of the wind forces that occur far outweighs the additional tension caused by the Cunningham stretcher and ultimately the mast itself is bent accordingly. Both effects have a greater impact on the luff than the Cunningham straightener.
The Cunningham straightener is named after its inventor, the American Briggs Swift Cunningham II , an America's Cup regatta sailor and racing driver. On some dinghies and yachts , a vertically movable lout fitting takes over the function of the Cunningham spreader.
Function and structure
.jpg)
The Cunningham straightener can be constructed differently for different boat types . Generally needed is a thimble (reinforced with a metal ring circular opening) in the canvas, almost at the luff and above the sail tack is attached, and a tether through whose Anholen or slackening caused the desired trim. The line of the Cunningham straightener runs through the throat. Some Cunningham stretchers are constructed as tackles (this construction is used to save strength); with them the Cunningham straightener is attached to the thimble with a becket . The loose part of the line (it can also use two ropes to be) the Cunningham is usually in a camcleat occupied .
The Cunningham straightener has a similar trimming function to the main halyard , but it is easier to operate and considerably more energy-saving, as it does not work against the pull of the main sheet and the boom vang.
Trim effected
With the help of the cunningham straightener you can tighten or loosen the canvas immediately behind the luff; this trims the mainsail. Trimming is done according to two criteria: on the one hand, according to the wind strength, and on the other hand, according to the course sailed.
In strong winds, for example, the Cunningham straightener will be used strongly - in light wind, however, it should be lowered. Otherwise, the course is trimmed: in the case of wind from a forward direction, i.e. on all close-hauled courses, the Cunningham straightener is usually strongly enforced; In the case of wind from a distant or astern direction, i.e. downwind courses, the Cunningham straightener is normally lowered, and the Cunningham straightener is also lowered on the half-wind course.
The enforcement of the Cunningham straightener results in a shift of the belly of the sail towards the neck of the sail, that is to the front and bottom, and a flat sail profile. Normally it is enforced until the possible transverse folds of the sail have disappeared. With a flat sail profile, a high course to the wind can be sailed. The enforcement of the Cunningham stretcher also shows one of its advantages over trimming with the main halyard, because while the leech remains open (curved or arched) when using the Cunningham stretcher (on some boats it even opens wider), when using the main halyard this becomes affects the entire sail, i.e. the leech closes (it no longer has any curvature or arching).
The lowering of the Cunningham straightener shifts the belly of the sail towards the middle of the sail and thus a more bulky sail profile. In addition, the sail belly becomes larger.
See also
- luff
- Kausch
- Mainsail
- Lout fitting
- Trim devices
- List of nautical technical terms . If some technical terms are unclear, look up here.
literature
- Ulf Biedermann, Andreas Gosztonyi: Regatta sailing for beginners and advanced . Nymphenburger Verlagshandlung GmbH, Munich 1982, ISBN 3-485-01657-8 .
Individual evidence
- ↑ a b Sail trim instructions on the website ( Memento of the original from February 14, 2009 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. of the Marinaclub-Krumpendorf: Archived copy ( Memento from December 8, 2009 in the Internet Archive )
- ↑ Dr. Harald Wozniewski: The Cunningham? - Another mistake! 1988. Retrieved July 27, 2009
- ↑ Trimming tips from Diekow-Segel. ( Memento of the original from June 10, 2009 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved July 27, 2009
- ↑ Sail trim instructions on the website of Heinz Kratz : http://www.heinz-kratz.de/segeltrimm.htm , sub-item 3.3
