Camber

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Camber

Camber is a transverse curvature of a ships decks. Cambered decks can add aesthetic value, add strength and stiffness to decks under load, and help shed water. Camber also reduces the visual lines produced by welded stiffeners on steel plate.

Contents

Camber Arrangement

Traditionally, in vessels with cambered decks, all decks except the tank top are generally parabolically cambered to equal proportions. A typical camber value is Breadth/50. Cambered decks typically maintain their profile relative to the centreline for the length of the deck (maximum camber occurs at maximum beam, reducing towards the bow/stern). This simplifies full-scale lofting, by allowing a single camber profile template to be used to define all deck structure curves. As these are typical construction details, there is much variability in their implementation.

Types of Camber

Camber examples - click for details

Parabolic

A parabolic camber has an exponentially increasing drop as it approaches the deck edge. Parabolic camber can be defined by a curve tangent to a horizontal line at the deck on centreline. The diagram shows one method of producing this geometry: the amount of camber desired considered as a rectangle at the maximum beam. The vertical and horizontal axises are then divided by a common whole number - in this example, 3. Horizontal guide lines are connected from the vertical divisions to the deck at centreline. A second set of vertical guide lines are run from the horizontal divisions perpendicular to the transverse axis. The intersection points can then be connected by a fair line to form the deck camber.

Conical

A conical camber maintains a constant radius from the deck centreline. Conical camber can be defined by an arc with a constant radius with the upper quadrant on the decks centreline. The diagram shows one method of producing this geometry: the amount of camber desired considered as a rectangle at the maximum beam. The vertical and horizontal axises are then divided by a common whole number - in this example, 3. Horizontal guide lines are connected from the vertical divisions to the deck at centreline. A second set of vertical guide lines are run from the horizontal divisions perpendicular to the horizontal guidelines. The intersection points can then be connected by a fair line to form the deck camber.

Straight

Straight, linear, or knuckled camber refers to camber made of flat plate, with one or two chines. Straight cambers are easier to manufacture and simplify design numbers. For vessels with large beams (i.e., drill rigs), straight camber is often more practical.

See Also

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