1. What is Hull Displacement?

Hull displacement refers to the weight of water displaced by a vessel's hull, which equals the total weight of the vessel. It's a fundamental measurement in naval architecture and marine engineering that indicates the size and carrying capacity of a ship.

2. How Does the Calculator Work?

The calculator uses the hull displacement formula:

Where:

• \( L_h \) — Length of the hull in meters
• \( B_h \) — Beam (width) of the hull in meters
• \( D_h \) — Draft (depth submerged) in meters
• \( C_b \) — Block coefficient (unitless)

Explanation: The formula calculates the volume of water displaced by the hull, which when multiplied by the density of water (approximately 1 ton per cubic meter for fresh water) gives the displacement in tons.

3. Importance of Hull Displacement Calculation

Details: Accurate displacement calculation is crucial for ship design, stability analysis, load capacity determination, and compliance with maritime regulations. It affects the vessel's buoyancy, stability, and performance characteristics.

4. Using the Calculator

Tips: Enter all measurements in meters. The block coefficient typically ranges from 0.5 to 0.9, with higher values indicating fuller hull forms. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the block coefficient (C_b)?
A: The block coefficient is a dimensionless value that represents the fullness of the hull form. It's the ratio of the underwater volume of the hull to the volume of a rectangular block with dimensions L × B × D.

Q2: How does salt water affect displacement?
A: Salt water is denser than fresh water (approximately 1.025 tons per cubic meter), so a vessel will displace slightly less volume in salt water to achieve the same displacement weight.

Q3: What's the difference between displacement and deadweight tonnage?
A: Displacement is the total weight of the vessel including everything on board. Deadweight tonnage is the weight of cargo, fuel, stores, and other items the vessel can carry.

Q4: Why is displacement measured in tons?
A: In naval architecture, "tons" typically refers to metric tons (1,000 kg) of displacement, which equals the weight of water displaced by the hull according to Archimedes' principle.

Q5: How accurate is this calculation method?
A: This formula provides a good estimate for preliminary design purposes. For precise calculations, naval architects use more sophisticated methods accounting for the exact hull form and water density variations.