Germanischer Lloyd (GL) has published new guidelines for data networks which are implemented onboard ships or offshore platforms. As the maritime industry makes greater use of automated systems data networks have become more and more complex, while also integrating safety-critical and non-safety-critical application systems. The guidelines are available for download now on the GL website and will enter into force on 1 August 2013.
One of the main reasons for the increasing number of application systems which are connected through data networks is to minimise the total length of cabling installed throughout the vessel. Minimising cable length not only reduces the material and installation costs for the cabling, but also avoids adding unnecessarily to the overall weight of the ship or the platform. This is especially relevant in cruise vessels, where the delivery of high quality interactive entertainment services to passengers is increasingly important.
In merchant shipping too, however, more and more vessels are equipped with integrated bridges that link information from the navigation and automation systems. Today, as well, modern automation systems are themselves complex integrated systems that comprise several monitoring sensors, control systems for the propulsion and power-generating systems, and monitoring and alarm systems.
A type approval would be required for data networks which connect application systems related to classification such as: automation system, navigation system, alarm & monitoring system, general alarm & public address system, comprising all the necessary for monitoring, control and safety including in- and output devices. Non-class related application systems would include entertainment systems such as: radio, television, audio and video on demand and private internet access. The required approval would cover the entire network, including routers, switches, and process controllers connected with network cables.
In order to follow a systematic and reproducible risk-based approach for the approval process, a so-called Requirement Class is assigned to the respective data network. The scope of documents to be submitted for approval and the required function tests depend on this assignment.
There are five different Requirement Classes, differentiating the individual network according to the magnitude of the damage which would result from a potential component or system failure and its effect on the persons onboard, the environment and the technical condition of the vessel. This approach follows the same procedure as the approval process for computer systems under GL’s Rules and Guidelines.
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