In Water Survey (IWS) for Ships – Marine Engineering
In Water Survey (IWS)
The CLASS will accept an In water Survey in lieu of the intermediate docking between Special Surveys required in a five year period on ships where an *IWS notation is assigned.
The In water Survey is to provide the information normally obtained from the Docking Survey. Special consideration shall be given to ascertaining rudder bearing clearances and stern bush clearances based on the operating history, on board testing and stern L.O. analysis.
The In water Survey is to be carried out at an agreed geographical location, with the ship at a suitable draught in sheltered waters and with weak tidal streams and currents. The in water visibility is to be good and the hull below the waterline is to be clean.
In Water Survey (IWS) Requirements
Prior to commencing the In water Survey, the equipment and procedures for both observing and reporting the survey are to be agreed between the Owners, Surveyor and diving firm. In water Survey is to be carried out by a qualified diver of a firm approved by the Class. If the In water Survey reveals damage or deterioration that requires early attention, the Surveyor may require that the ship be dry-docked in order that a fuller survey can be undertaken and the necessary work carried out.
Where a vessel has an *IWS notation, the conditions of the high resistant paint is to be confirmed at each dry-docking in order that the *IWS notation can be maintained. Where an *IWS (In water Survey) notation is to be assigned, plans and information covering the following items are to be submitted:
- Details showing how rudder pintle and bush clearances are to be measured and how the security of the pintles in their sockets is to be verified with the vessel afloat.
- Details showing how stern bush clearances are to be measured with the vessel afloat.
- Details of high resistant paint, for information only.
Where an *IWS notation is to be assigned, means are to be provided for ascertaining the rudder pintle and bush clearances and for verifying the security of the pintles in their sockets with the vessel afloat.
Where an *IWS (In water Survey) notation is to be assigned, means are to be provided for ascertaining the clearance in the stern bush with the vessel afloat.