Question

with reference to the classification of ships, explain each of the following:

(a) Why ships are built to classification society rules.

(b) The meaning of the notation 100A1.

(c) How a ship remains in class throughout the life of the vessel.

Answer 1

Part (a)

The cost of insurance of both ship and cargo depends largely upon the classification, the higher standard requiring smaller premiums. It is, therefore, to the advantage of the ship-owner to have a high-class ship. However, the classification societies are independent of the insurance companies. Each of the classification societies has its own rules, but there is a similarity between them, and they are used to determine the scantlings of the structural members.

The scantlings of the structure are based on theory, but because a ship is a very complex structure, a `factor of experience' is introduced. The classification societies receive reports of all faults and failures in ships that carry their classification, and based on these reports, consistent faults in any particular type of ship may be analysed, and amendments made to the rules.

The scantling plans are submitted to the classification societies for their approval before the detailed plans are drawn. The procedure should ensure the quality of build for the vessel, which, when built in accordance with the classification society rules, is assigned a class. This class applies as long as the ships are found under survey to be in a fit and efficient condition.

Part (b)

The notation ✠100 A1 means suitable for seagoing service on long international voyages built to the highest standard with a surveyor in attendance.

Class A is assigned to ships that are built in accordance with the rules or have equivalent strength.
Figure '1' is added (i.e. 100 A 1) when the equipment, consisting of anchors, cables, mooring ropes and towropes, is in good and efficient condition.
✠ Is added to the `100 A 1' notation when a ship is fully built under Special Survey, i.e. when a surveyor is in attendance and examines the ship during all stages of the construction.

Part (c)

To ensure that the ship remains worthy of its classification, annual docking and special surveys are carried out by the surveyors. Docking surveys are approximately every 2½ years, whilst special surveys are carried out at intervals of 4 to 5 years also, any structural changes are to be agreed with the classification society before starting.

✓ Verified Model Answer (Text Solution)

The notation ✠100 A1 means suitable for seagoing service on long international voyages built to the highest standard with a surveyor in attendance.