Ships Drawing

Ships drawing.

Topic learning objective: the first topic leads to a clear picture of the hull form characteristics, signs, students learn to identify these characteristics and to understand what their impact on the seaworthiness of the ship is.

This theme also includes methods for the approximate determination of areas and volumes bounded by curved lines or curved planes.

1.3. The coordinate axes and the trim of the vessel

- Midships section - a vertical cross-sectional plane, which is the theoretical length of the ship in the middle;

- Length of the vessel. Ship static problem solving is used in the calculation of two lengths: the length between the fore and aft perpendicular (LENGTH BETWEEN PERPENDICULARS-LBP) and the ship's maximum length (LENGTH OVER ALL-LOA);

- Breadth of the ship (BEAM -В), is measured at the load waterline between the inner surfaces of the side plating;

- Side height (DEPTH - H), is measured in the plane of the midsection, from the base line to the lower edge of the upper deck flooring of waterproof deck.

B / d - characterizes the stability and salability of the vessel;

To characterize the shape of the hull the dimensionless coefficients of fineness are used:

 fineness of waterline factor (Coefficient of fineness of water-plane area Cw)

Coefficient of waterline fineness (Coefficient of fineness of water-plane area Cw) - the ratio of spare Aw waterline to the area of a rectangle with sides of equal length L and width of the vessel B (Figure 4).

Coefficient of fineness of midsection (Midships coefficient CM) - the ratio of spare midsection Am to the area of a rectangle with sides equal to the width B and the draft d (fig. 5).

where V - volume of the underwater hull (volume of displacement).

where D - the vessel's weight displacement equal to the weight of water displaced;

Prismatic coefficient of fineness (Longitudinal prismatic coefficient CP) - the ratio of the underwater hull to the volume of a prism with a base equal to the square of midship section Am and a height equal to the ship's length L. (Figure 7)

Typical coefficients of fineness and the ratio of the main dimensions can be seen in Appendix 1.

Determine the hull underwater part volume, the waterline area, the midships area and prismatic coefficient of fineness of the vessel, which elements are:

Determine block coefficients of the horizontally floating cylinder if its draft is equal to half of its width.

1. Determine the area of midships, where the length - 72 meters. Midships fineness factor is 0.91; hull ratio of length to width - 6, of width to draft -3.

2. Determine the vessel's underwater part volume, the waterline area, midships area and missing ship fineness coefficients, if the length - 150 m, width - 20 m, draft - 7.5 m, a joint block coefficient is 0.7; waterline fineness coefficient is 0.85; midships fineness coefficient is 0.96.