Page 356 - statbility for masters and mates

344 Ship Stability for Masters and Mates
moving head-on to waves whose length is the same as that of the ship, and when there is either a wave crest or trough situated amidships.
To calculate the bending moments and consequent shearing stresses created in a ship subjected to longitudinal bending it is ®rst necessary to construct diagrams showing the longitudinal distribution of weight and buoyancy.
The weight diagram
A weight diagram shows the longitudinal distribution of weight. It can be constructed by ®rst drawing a base line to represent the length of the ship, and then dividing the base line into a number of sections by equally spaced ordinates as shown in Figure 41.10. The weight of the ship between each pair of ordinates is then calculated and plotted on the diagram. In the case considered it is assumed that the weight is evenly distributed between successive ordinates but is of varying magnitude.
Let
CSA Cross Sectional Area
Fig. 41.10. Shows the ship divided into 10 elemental strips along her length LOA. In practice the Naval Architect may split the ship into 40 elemental strips in order to obtain greater accuracy of prediction for the weight distribution.