Unit12AnchoringandBerthingOperations..doc

Unit 12 Anchoring and Berthing Operations 锚泊操纵 I BERTHING IN WIND 风中锚泊 1. The center of lateral resistance 侧向阻力中心 The force of the wind causes the ship to drift and, by doing so, hydrodynamic forces act on the underwater hull to resist the effect of the wind. The point of influence of these underwater forces is known as the centre of lateral resistance(CLR) and is the point on the underwater hull at which the whole hydrodynamic force can be considered to act. Similarly, there is a point of influence of wind(W) which has an important relationship with the CLR. W is likely to alter frequently as it will change in relation to the wind direction and the ship’s heading. 风的作用使船舶偏航,这样,水动力作用于水下船壳抵消风的效果，这些水下部分作用力的中心被称为侧阻力的中心(CLR),也可以理解为是在整个动力的力量对 船壳的作用中心。同样的,其中有一个风的作用点(W) 跟CLR有着重要的关系。,由于风风向和船舶航向的相对变化，风力作用中心常常是变化不定的。 To anticipate the affect wind will have on a ship’s heading, W must be viewed in relation to CLR. 为了预测风力作用如何影响船舶航向,我们必须把风的作用看做作用在侧向阻力中心。 Ship handlers prefer to refer to pivot point (P) rather than CLR when discussing the effects of wind on a ship with headway or sternway . However, a stopped ship does not have a pivot point and for this reason CLR should always be used. In the discussion which follows, CLR is used for a stopped ship and P for a ship with motion. 当讨论风力作用对船首向/船尾向的影响时，，船舶操纵者更喜欢引用转心(P) 而非CLR。然而,静止的船舶是没有转心的 ,因为这个原因,CLR也经常被使用。在接下来的讨论中,CLR是用在 静止的船而转心是用在航行的船舶。 2. The point of influence of wind 风力作用中心 The point of influence of wind (W) is that point on the ship’s above-water structure upon which the whole force of the wind can be considered an act. 风力作用中心(W)是可以被认为是作用在船舶上层建筑的风力作用的那一点。 Unlike a ship’s centre of gravity, the point of influence of wind moves depending on the profile of the ship presented to the wind. When a ship ‘s beam is facing to the wind, W will be fairly close to the mid-length point, slightly aft in the case of ships with aft accommodation and slightly forward if the accommodation is fo