TONNAGE MEASUREMENT

• This is often referred to when the size of the vessel is discussed, and the gross

Tonnage.

• Tonnage is a measure of the enclosed internal volume of the vessel, 100 cubic

feet representing one ton.

• Its normally divided into categories as follow:-

1. Displacement Tonnage

• A ship’s displacement is the sum of the ship’s actual weight [light weight] and it’s contents [deadweight].

• The metric unit of measurement is 1 tonne [=1000 Kg].

• The displacement represents the amount of water displaced by the ship expressed in tonnes.

• The weight of water displaced therefore equals the weight of the ship

TONNE PER CENTIMETRE (TPC)

It is the mass required to increase the mean draught by 1 centimetre.

LOAD DISPLACEMENT

The weight of the ship and its content, measured in tonne. The value will vary according to the ship’s draught.

DEADWEIGHT SCALE

It is a scale diagram indicating the deadweight of the ship at various draughts.

FORM COEFFICIENT

It is devised to show the relationship between the form of the ship and the dimension of the ship.

2. Lightweight Tonnage (LWT)

• The lightweight is the weight of the ship as built (hull, machinery) including boiler water, lubricating oil and the cooling water system.

• Lightweight like displacement is expressed in units of tones.

• It assumes importance in a commercial sense only when considering the value of the vessel which is to be broken up for scrape.

3. Deadweight tonnage (DWT)

• Deadweight is the weight of the cargo which a ship carries plus weights of fuel,

stores, water ballast, fresh water, crew and passengers and baggage.

• It is the difference between the loaded ship displacement and the lightweight.

4. Gross Tonnage (GT)

• Measurement of total internal volume of a vessel and includes all under deck

tonnage and all enclosed spaces above tonnage deck.

• 100 cubic feet of space being considered as 1 ton

5. Nett Tonnage (NT)

• Ship measurement derived from gross tonnage by deducting spaces allowed for crew and propelling power.

• 100 cubic feet of space being reckoned as 1ton

SHIP CERTIFICATES

P&I certificate

International Tonnage certificate

Ship registry certificate

International ship security certificate

Safety management certificate

Certificate of class and CAS / CAP for tankers

Document of compliance

IOPP

Loadline certificate

PSC / FSI

Cargo Ship Safety construction certificate

Cargo Ship Safety equipment certificate

Cargo Ship Safety radio certificate

Ship sanitation control exemption certificate