This document is a Final Draft International Standard (FDIS) published by ISO. An FDIS is a Draft International Standard that has previously been approved by ISO members, and is issued for a final Yes/No vote within a period of two months from publication. Note that if technical comments are received during this period, they are no longer considered at this stage, but registered for consideration during a future revision of the International Standard. In the rare event of an FDIS not being approved, the FDIS is referred back to the originating Technical Committee for reconsideration in the light of the technical reasons submitted in support of the negative votes received.
ISO 20283-2:2008 gives guidelines, and specifies requirements and procedures for the measurement, diagnostic evaluation and reporting of structural vibration of ships, excited by the propulsion plant. Structural vibration can be of global or of local nature. Here, primarily global vibration is dealt with.
Local vibration of deck structures from a habitability point of view is dealt with in ISO 6954. Occurrence of local vibration leading to fatigue damage is rare and strongly related to the individual configuration. Therefore, no general guideline for the measurement of such type of vibration is provided within the scope of ISO 20283 (all parts). For reference, some basic information regarding the design of structures with respect to local structural vibration is provided.
ISO 20283-2:2008 does not consider transient ship vibration phenomena, e.g., as excited by slamming.
Even though torsional shaft or crankshaft vibration may in some cases cause relevant structural vibration, they are not considered here. In this connection, reference can be made to the relevant classification rules and ISO 20283-4.