Canting keel
Under the name Kippkiel is defined as a keel, which can be pivoted about a longitudinal axis lying deep inside the ship to windward, so as to increase the righting moment of the keel bulb.
In modern boatbuilding is spoken generally by the Canting Keel. Used also be the names swing keel and swing keel.
The weight saving on the keel bulb and the fact that the ship can be moved with less heeling ( upright ), results in a higher boat speed. The swing keel is a remarkable, but not yet technically mature, innovation in sailing.
Technology
Traditional fin keels have the disadvantage that their righting moment only comes into play when the boat is heeled. The purpose of Kippkiels is to develop high righting moment even with low heel.
The keel is swung by means of hydraulics ( in rare cases with cable ) about a longitudinal axis which lies in the hull. It can be used structures with one or two hydraulic presses, where weight savings over reliability is.
The problem the passage point of the keel is through the hull. The body opening must be relatively large due to the opposite inside of the hull axis of rotation. In most constructions of the hull is sealed by means of rubber. This seal is designed to be water tight, but would the water pressure at high speeds not withstand. So the passage is through the hull (in addition ) secured by means of so-called bomb doors, which in addition to the seal even hydrodynamic point of benefit.
To reduce the drift of the vessel, one or more additional swords must be used in Kippkielern.
Problems
The problem is the price of this elaborate keel design in the first place. So far, it is almost exclusively on a few race boats used (shock 40, Cookson, Volvo Open 70, Open 60, Mini 650). At normal cruising yachts, this technique has therefore held no collection until now. This is in addition to the high cost and the space required and not yet fully mature technology.
The Volvo Ocean Race 2005-2006 was one of the first long-distance offshore races in which this technique was used. Several ships had problems with this technique; this eventually led even to the loss of a ship. The error was due to the underestimated dynamic forces that govern the keel design at high speeds and sea conditions. Most problems occurred to the hydraulic stamping the keel adjustment as well as the sealing of the Kiel passage point on the hull.
Swell
- Canting Ballast Twin Foil Technology
- Sailing ship