BV publishes Rule Note on the Condition Monitoring Systems

Classification society Bureau Veritas has published the Rule Note on the Condition Monitoring Systems.

This Rule Note was published on February 1st, 2023.

Application

This Rule Note applies to design, installation and testing of permanently installed Condition Monitoring Systems (CMS) where condition monitoring results are used to influence the scope and/or frequency of Class surveys.

The objective of a Condition Monitoring System is to provide an equivalent or greater degree of confidence in the condition of the machinery to traditional survey techniques.

This Rule Note applies to permanently installed CMS of type A or B, and does not apply to tailshaft monitoring system.

Review of CMS of predictive type will be handled on a case-by-case basis. In that case, a written agreement from the Original Equipment Manufacturer (OEM) is to be provided to the Society.

Requirements for Condition Monitoring System

A human machine interface (integrated or stand alone) is to be provided on-board to enable CM data visualization, followup of CMS breakdown and log display.

Note 1: The Chief Engineer is the responsible person on board in charge of CMS, and therefore sufficient information and instrumentation are to be made available on-board for his use.

CMS are to be capable, through their own interface or integrated in another system, to produce a condition report and maintenance recommendation.

CMS are to include a method for backing up data at regular intervals, to prevent loss of data in case of CMS failure (e.g. CMS data, software...).

The operation or the installation of a CMS is not to have any impact on the equipment, or on the availability or functionality, of computer based systems already installed on board. A risk assessment report may, be requested by the Society.

Components

Systems or components, as indicated in NR467, Pt C, Ch 2, Sec 15, [2], are to be chosen from among the list of type approved products.

They are to be approved on the basis of the applicable requirements and in particular the ones defined in NR467, Part C, Chapter 3.

Note 1: All sensors, transmitters and data processing equipment already used within the scope of notations AUT-UMS, AUT-CCS, AUT-PORT or AUT-IMS may be used as an input for CMS. Case-by-case approval may also be granted at the discretion of the Society, based on submission of adequate documentation and subject to the satisfactory outcome of any required tests.

Installation of sensors are to be performed by a personal qualified for condition monitoring. Sensors are to be permanently marked or labelled.

Installation of cables is to follow approved cable tray path. Cable installation is to comply with the requirements of NR467, Pt C, Ch 2, Sec 12.

Note 1: Where it may not be possible/suitable for permanent markings or labels, exact location could be shown in schematic drawings, machinery information diagrams or photos.

Computer based systems

CMS of Type A for which functions are performed through computer based systems are to comply with the requirements of NR467, Pt C, Ch 3, Sec 3, as Category I system:

software functional description and associated hardware description is to be submitted for information
test programs for on board tests, including wireless network testing, are to be submitted for information
acceptance testing and on board tests, as described in NR467, Pt C, Ch 3, Sec 6, [3] and [4], are to be witnessed by the Surveyor.

Pre-integrated systems are to comply with the requirements stated in NR467, Pt C, Ch 3, Sec 3, [8].

Alarms and failures

CMS are to be self-checking and able to detect faults, malfunctions or interruptions of its different parts: data acquisition (DA), data processing (DP), diagnostic and prognostic assessment (D & P) and health management (HM), as defined in NI684.

Especially, it is to be able to detect the following when applicable:

Loss of main source of power or low battery.
Sensor faults (e.g. missing value, calibration expired, value outside range, slope excess, constant value…). The list of detected faults is to be specified.
Loss of communication or network failures.
Failure of storage device.
Storage capacity nearly complete (e.g. 90% storage warning).
Software abnormal operation.
Processor failure (e.g. overheating).
Loss of UTC synchronization.

Detected failures are to initiate an alarm and are to be logged in the system. A no-fault condition is to be positively indicated (e.g. green light).

Note 1: For data quality concerns, it is recommended that a system is implemented on board to ensure that, data recorded during an identified fault or malfunction event, are flagged appropriately as untrustworthy data. The list of flag definitions is the responsibility of the designer.

Cybersecurity

Access to computerized systems for modification of CMS parameters are to be secured (e.g. username/password).

Note 1: Access is to be restraint to the Chief Engineer or other authorized person.

Where CMS use remote monitoring or diagnosis (i.e. data is transferred from the vessel and analyzed remotely), the system is to be capable to maintain continuous on-board operation in the event of loss of the communication function.

In addition, the system is to comply with the applicable requirements for cyber security of equipment in accordance with NR659 “Rules on cyber security for the classification of marine units”.

Traceability

CMS parameters

A system is to be provided to identify where CMS parameters (e.g. baseline, limiting parameters, data collection task interval, sampling time...) are modified during the operation.

Parameters and user performing the modification are to be logged in the system.

CMS operation data

CMS are to have the ability to store, or to communicate to external storage, the CMS operation data according to NR467, Pt A, Ch 2, App 4.

Note 1: Refer to “Data storage and backup” as defined in NI684, Sec 2, [5.3].