Comfort class notation addressing noise and vibration

Purpose

To comply with international standards for noise and vibrations (V) that influence the well-being of crew and passengers, as well as those affecting the safety and operability of the vessel.

Benefits

The comfort on board is an important quality of the vessel. A high level of comfort increases the performance and vigilance of the crew and, consequently, the safety of the ship and cargo. For a passenger ship, the comfort will be significant for the ship's rating and reputation in the market. Noise and vibration comfort is a significant parameter in this respect.

Features

Vessels which fulfil the requirements applicable to this notation will be given the additional class notation COMF-V(crn). The requirements for onboard noise and vibration limits are divided into three groups depending on the level of comfort achieved, i.e. comfort rating number (crn) 1, 2 and 3. Where 1 represents the highest level of comfort and 3 represents an acceptable level of comfort.

Compliance with the rules is to be verified through measurements of defined ship-type specific noise and vibration parameters and criteria.

The requirements for the notation are specific for the various ship types, and are furthermore divided into groups for specified locations. For offshore service vessels to be operated in DP (Dynamic Positioning) mode, noise and vibration measurements are to be carried out with the side thrusters in operation. For passenger ships, the given comfort rating number applies to the passenger accommodation only. The crew accommodation is to comply with the minimum rating (crn) 3 for cargo ships.

The main parameters used to describe the comfort level are: noise, sound insulation, impact sound insulation and vibrations.

A test programme is to be approved prior to the verification measurements. The test programme must as a minimum include the following information:

• specification of measurement locations
• required loading conditions
• required operating conditions for machinery
• the instrumentation to be used