ISO DIS 21984

Description / Abstract: This document gives guidelines for the measurement, evaluation and reporting of vibration with regard to habitability for all persons on board ships satisfying one or both of the following conditions:

a) 2-stroke cycle, long-stroke, low-speed diesel engine directly coupled to the fixed-pitch propulsion propeller is installed.

b) length of deck house (L) is limited as compared with its height (H) (i.e., deck house of around 1,0 in slenderness ratio of H to L and above). An example of length of deck house (L) and its height (H) for slenderness ratio is shown in Annex A.

Overall frequency-weighted r.m.s. vibration values in the frequency range 1 Hz to 80 Hz are given as guidance values for different spaces on ships.

This document is applicable to specific ships with intended voyages of 24 h or more.

This document specifies requirements for the instrumentation and the procedure of measurement in normally occupied spaces. It also contains analysis specifications and guidelines for the evaluation of ship vibration with respect to habitability.

This document is not applicable to machinery spaces, other than engine control room, where persons do not stay for a prolonged periods of time.

ISO 20283-5 is generally applicable to all ships. Requirements for measurement, evaluation and reporting of vibration with regard to habitability for all persons on board of passenger and merchant ships, including specific ships to which this document may also be applicable, see ISO 20283-5. This document is neither complementary nor additional but supplementary to ISO 20283-5. The evaluation of low-frequency ship motion which can result in motion sickness is covered by ISO 2631-1. For the evaluation of the global structural vibration of a ship, however, see ISO 20283-2.