The document defines and classifies different tonnage systems used for ships. There are two main classifications - volume tonnage and weight tonnage. Volume tonnage includes gross tonnage, net tonnage, and freight tonnage which measure the internal volume of a ship. Weight tonnages measure the weight of different aspects of a ship and include displacement tonnage, lightweight tonnage, and deadweight tonnage. Displacement tonnage represents the total weight of water displaced by a ship, lightweight tonnage is the structural weight of the ship itself, and deadweight tonnage refers to how much cargo weight can safely be carried.

1. TONNAGE SYSTEM
PRESENTED BY
ATSHAYA.S
BFT16122

3. TONNAGE DEFINITION:
• It is the weight in tons or the carrying capacity of the ship.
• 1 ton=1000kg
• specifically refers to a calculation of the volume or cargo volume of the ship.
• The word ‘ton’originally came from the word ‘tun’ which was a casket used to
carry wine.

4. TONNAGE CLASSIFICATION:
Volume tonnage
• Gross tonnage
• Net tonnage
• Freight tonnage
Weight tonnage
• Displacement tonnage
• Deadweight tonnage
• Lightweight tonnage

6. DISPLACEMENT TONNAGE:
• This represents the amount of water displaced by a ship expressed in tons
weight.
• Normally the total weight of ship in running condition at any particular draft .
Displacement =DW+LW
*Standard displacement tonnage:
• Displacement tonnage – (the weight of any fuel and potable water carried
on board the ship)

9. LIGHT WEIGHT TONNAGE:
• It is best described as the weight of the ship when it was built in the shipyard
including all framing,machinery,decking etc.
• It does not include the weight of any comsumables such as fuel ,water,oil,or
supplies.

11. DEADWEIGHT TONNAGE:
• It is the weight of all the cargo,fuel,dry provisions,supplies,etc.carried
onboard the ship.
• In other words,
• Deadweight=“displacement tonnage”- “lightweight tonnage”
• Just the measure of how much weight a ship can carry safely.

14. GROSS REGISTERED TONNAGE:
• Gross tonnage(GT) is a function of the volume of ship’s all enclosed spaces.
Net registered tonnage:
• It is the measure of the ship’s earning capacity .
• Only the cargo carrying space .

16. FREIGHT TONNAGE:
• This is the measure of ship’s
capacity to carry the cargo
Expressed in tons.