Tonnage

Question 1

Volumetric Tonnage

Answer 1

100 ft^3 = 1 ton. Determines earning capacity and port fees. Measure by volume rather than weight.

Question 2

Gross Tonnage

Answer 2

Internal volume of the ship. Total ship tonnage.

Question 3

Net Tonnage

Answer 3

Remaining volume after non-earning spaces.

Question 4

Non-earning space examples

Answer 4

Double bottoms, bridge, forepeak and aftpeak, shelter deck, companionways etc. Spaces not used for cargo

Question 5

Deductions

Answer 5

Same as non-earning spaces, crew/working space, machinery space.

Question 6

Shelterdeck

Answer 6

Weather deck not considered fully water-tight if fitted with tonnage openings

Question 7

Tonnage openings

Answer 7

Not water-tight, no gasket, secured with bolt hooks. Non-earning space.

Question 8

How to know spaces are meant for working only

Answer 8

Builder puts a plaque up to specify

Question 9

Suez and Panama Canal Tonnage

Answer 9

Have their own rules for determining tonnage. Usually more than net tonnage.

Question 10

Weight Tonnage

Answer 10

Based on the weight rather than volume. 3 classifications: Deadweight, displacement, and lightship.

Question 11

Deadweight

Answer 11

Cargo + water + fuel + stores a ship can hold at full capacity.

Question 12

Displacement

Answer 12

Weight of the water displaced by the hull. Includes everything on the ship.

Question 13

Lightship

Answer 13

The weight of the ship while empty