1. What is Gross Tonnage?

Definition: Gross tonnage (GT) is a unitless index related to a ship's overall internal volume, calculated using the vessel's total enclosed volume and a multiplier.

Purpose: It's used to determine things like manning regulations, safety rules, and registration fees for ships.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( GT \) — Gross tonnage (unitless)
• \( K \) — Coefficient (typically 0.2–0.3)
• \( V \) — Total enclosed volume in cubic meters (m³)

Explanation: The total enclosed volume is multiplied by a coefficient that accounts for the vessel's type and configuration.

3. Importance of Gross Tonnage Calculation

Details: Proper GT calculation is essential for ship registration, compliance with international regulations, and determining applicable safety standards.

4. Using the Calculator

Tips: Enter the coefficient (typically 0.25) and total enclosed volume in cubic meters. The coefficient must be between 0.2 and 0.3.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between gross tonnage and displacement tonnage?
A: Gross tonnage measures volume, while displacement tonnage measures actual weight of water displaced by the vessel.

Q2: Why does the coefficient vary between 0.2 and 0.3?
A: The coefficient accounts for different vessel types and configurations, with higher values for ships with more enclosed spaces.

Q3: How do I find the total enclosed volume?
A: This is typically calculated from the ship's plans by naval architects or marine surveyors.

Q4: Is gross tonnage the same as net tonnage?
A: No, net tonnage subtracts non-revenue producing spaces and is generally about 30% less than gross tonnage.

Q5: What regulations govern gross tonnage calculations?
A: The International Convention on Tonnage Measurement of Ships (1969) establishes the universal method.