DNV GL SHIP TECHNOLOGY I-1-17 PDF

These Guidelines for Machinery Condition Monitoring apply to the machinery of ships, which are classified by Germanischer Lloyd (GL), and for which a Survey Arrangement CM has been concluded between the owner/operator of the ship and GL.

These Guidelines can be applied to new ships and to existing ships. For already existing ships, for which a Survey Arrangement CM will be requested, special considerations concerning their actual wear and tear condition have to be undertaken.

These Guidelines apply in addition to the GL Rules for Classification and Construction.

The Guidelines set out GL's general requirements regarding Condition Monitoring, which are the basis for the acceptance of Condition Monitoring with respect to Condition Based Survey.

If a Condition Monitoring System is used in the frame of a monitoring and control system and/or a safety system, the respective GL Rules for monitoring and control systems and/or for safety systems shall be applied, see in particular Chapter 3 – Electrical Installations, Section 9, B.

For propeller shafts running within the stern tube in oil under special conditions the intervals between shaft withdrawals may be prolonged and the Class Notation CM-PS may be assigned, see Chapter 2 – Machinery Installations, Section 4, D.

Purpose

The purpose of Condition Monitoring Systems is to detect ongoing deterioration, especially wear and tear, of Machinery Components or parts of them. For this purpose values of significant parameters are to be collected with the aid of an adequate measurement chain. The values shall be suitable to show an obvious trend of the monitored deterioration over a period of time.

Condition Monitoring Systems shall be capable of producing relevant data trends from the values collected and compare them with pre-defined acceptance criteria (e.g. limit curves).

Condition Monitoring for a Machinery Component, or parts of it, will be accepted by GL, if it is capable of producing reliable and trustworthy information for determining the actual condition of the Machinery Component, or parts of it.

The condition determination of a Machinery Component or parts of it, achieved from a GL accepted Condition Monitoring System, will be considered equivalent to condition determination by direct inspection, compare Section 4.