BIS

container carrier

Class notation for ships built for in-water survey of ship's bottom and related items.

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Purpose

To prepare the ship by marking a ship's underwater hull, arrangement of sea chest, rudder and propeller shaft, ensuring that a bottom survey may be efficiently carried out with the vessel afloat.

Benefits

Provided there is good visibility in the water, some of the bottom surveys required by class and Flag states may be carried out by recognised diving companies with the vessel afloat. Subject to limitations that apply to certain combinations of ship type and age, the notation allows for less frequent dry docking as every alternate bottom survey may be carried out with the ship afloat provided this is acceptable to the flag state.

The notation meets the requirements of some Flag states regarding the marking and arrangement of the vessel to allow alternate annual bottom surveys to be carried out afloat.

Features

The drawing approval and survey during the newbuilding stage ensures:

  • The markings of the side and bottom

  • The arrangement of openings in sides and bottom below the waterline, bottom plugs, echo sounder and any other underwater equipment

  • Details showing how rudder bearing clearance can be measured

  • That the arrangement of any impressed current system is such that a bottom survey may be efficiently carried out with the vessel afloat. The necessary drawings and photographs are to be kept on board for use by the DNV surveyor and diving company.

Process

The BIS class notation may be assigned to vessels upon delivery from the newbuilding yard or in connection with a dry docking upon successful review of the drawings/plans and verification on board.