Block coefficient

The block coefficient of a ship is calculated as the ratio of the underwater volume of the ship's hull (turquoise) to the volume of a rectangular block with the same total length, width and depth.

Under the block coefficient or Völligkeitsgrad (short and solidity ) is understood in the shipbuilding , the ratio

• an area of ​​any shape to the area of ​​the circumscribing rectangle
• an arbitrarily shaped body to the volume of the circumscribing cuboid

Examples are:

• Waterline completeness: This is the ratio of the waterline area (the water area, which is "missing" in the water surface due to the floating ship) to the area of ​​a rectangle calculated from the length and width of the ship.
• Completeness of the underwater hull: The ratio of the volume of the part of the hull located below the waterline (so-called displacement) to the cuboid volume calculated from the length, width (each measured in the waterline) and draft of the ship. This value is also called the block coefficient .

In practice, both parameters are not independent of one another. In the ship design, they serve as the starting point for determining the desired combination of speed, load capacity and required propulsion power of the ship.

calculation

Mathematically defined, the block coefficient C _B indicates the ratio between the displaced volume of the ship and the block   L _pp  ×  B   ×  T   : ${\displaystyle \nabla }$

${\displaystyle C_{B}={\frac {\nabla }{L_{pp}\cdot B\cdot T}}}$

The smaller C _B , the “slimmer” the ship. High-speed vessels usually have a small C _B . The block coefficient is as solidity referred. Since all of these factors can change with the change in draft, the block coefficient C _B can also change depending on the load.