krängning

Krængning is the term for the tilt or roll of a body about its longitudinal axis. In nautical usage it refers to the heeling of a sailing vessel caused by lateral forces, such as wind acting on sails or waves. The concept also appears in other contexts, including aviation (bank or roll), and the tilting of mechanical platforms or structures.

In sailing, krængning arises when forces on the hull or sails create a moment that tips the vessel away from an upright position. The heel angle, measured in degrees, is the amount of tilt from vertical. Stability depends on the geometry of the hull and ballast system, particularly the center of gravity, center of buoyancy, and the metacenter. The metacentric height (GM) is a key indicator of initial stability: a larger GM generally means a stronger righting moment, which tends to return the vessel to upright as it heels. The righting moment increases with heel angle up to a point, after which it may decrease and the vessel becomes more prone to capsizing.

Managing krængning involves ballast distribution, weight placement, and sail trim to control the heel and maintain adequate stability. Designers aim for sufficient initial stability to resist capsizing while allowing enough heel for performance and maneuverability. Outside nautical contexts, krængning can describe any intentional or natural tilting of a structure, vehicle, or system, with related concerns about safety, control, and performance.