How a classification society works

Malcolm Latarche
Malcolm Latarche

03 January 2018

It is important to understand that a classification society is mostly commercial organisations and except in a very small number of flag states, the need for ships to be registered with a classification society is not a legal requirement. However, ships that are not classed will have difficulty in obtaining first rate employment unless operating and carrying only its owner’s own cargoes.

Owners are usually free to chose which classification society their ships will be entered with but those operating at the top end and middle of the market will mostly choose one of the members of IACS because these generally have a high reputation among insurers.

An owner may choose a class society based on various considerations such as nationality, expertise in certain ship types, established existing working relationship or pressure from the flag state. If the ship is an existing one being obtained secondhand the shipowner can opt to stay with the society currently classing the ship or decide to transfer to another society. In such cases the new Classification Society will wish to see past records of the vessel but will only accept the ship following a very rigorous inspection of the vessel. Depending on the apparent condition of the vessel and her past record the new society may wish to inspect the vessel in dry dock.

Shipowners looking to class a new building can opt to have the ship built ‘under survey’. In order for this to happen the following sequence of events will occur:

  • The plans will be scrutinised and if found satisfactory approved by the Society.
  • The building of the vessel will be supervised by a surveyor from the society which will maintain a programme of constant spot checks and examinations to ensure that the rules of the Society are being met. He will also ensure that the material used is of a quality approved by the Society.
  • The final sea trials of the new building will be attended by the surveyor. Provided everything is satisfactory the vessel will then be formally entered as ‘Classed’ with the Society and will have the added qualification ‘built under survey’.

Having a vessel built under survey will give the owner the added comfort that the builder was not able to make ‘economies’ in construction that might later prove disastrous.

Classification Society - Surveys

Having been accepted and classed by a Society, to maintain its class the vessel will then have to enter a programme of surveys. This programme will ensure that everything on board the vessel which is material to its safety is surveyed in rotation according to a pre-determined timetable.

These surveys are scheduled so that every item will have been inspected at the end of a period of around 4 to five years. Once this cycle has been completed satisfactorily the vessel will have completed its first special survey whereupon the entire ‘cycle’ of surveys begins all over again. Inserted into this programme is usually a requirement that the vessel is dry docked twice during the survey cycle although some extended periods without drydocking may be acceptable depending upon ship type and age.

In the event of any accident happening to the ship or its equipment, the classification society may require an immediate survey of the damage and any repairs that may be deemed necessary. If a postponement of repairs is allowed by the classification society, the full details are entered in the vessel’s records as a ‘recommendation’. The eventual repair will have to be done under the supervision of the classification society’s approved surveyor.

The link between poor ships and the class societies they choose to work with has been noticed by Port State Control officials and the class societies’ records are included in annual statistics of Port State Control regions. Indeed some types of deficiency are directly attributable to the classification Society. This link and the recording of deficiencies have encouraged the better Societies to take steps to improve their own standards.

Class Notations

The role of the classification society as a third party endorser of the quality of ships demands that some means of indicating the quality and special characteristics of the ship is readily available to be shown to interested parties. This is done by means of class notations.

In the early days these notations were very simple; Lloyd’s Register’s first notation system assigned A, E, I, O or U to the condition of the hull in descending order of standard and G, M or B to the ships equipment – again in descending order. So the very best ships would be AG and the worst ships UB.

This symbology has grown ever more complicated over time so that a modern ships class notation might today be a veritable alphabet soup that indicates a ship built under survey, different types of equipment installed, ice class, whether the classification society's own software was used for designing the ship, unmanned machinery spaces, unmanned bridge, green credentials and most recently whether the ship’s owners practice cyber security. The final notation for a sophisticated vessel may extended to many lines of text.

Since each classification society has produced its own unique set of notations, comparing even identical ships entered with different societies can be a time consuming operation for say a shipbroker or insurer. An indication of the number of possible notations can be gauged from this listing of DNV-GL . Other classification societies will have similar lists.