Safety is the priority at LNG terminals, which are growing in number inline with an increased demand for the fuel. Like many fuels, LNG is potentially hazardous and to help reduce the possibility of an incident during berthing or when a vessel is alongside a jetty, integrated mooring systems are becoming standard specification. These incorporate advanced software focused on remote operation and second by second recording of events during berthing and while the vessel is moored. Trelleborg Harbour Marine, a leader in this field, outlines the state-of-the-art equipment used.
Short version of article:
Trelleborg Harbour Marine helps moor vessels safely at LNG terminals
The use of a single, integrated mooring system has increased substantially over the past three to four years as jetty operators have recognized the benefits this might offer. Integrated systems are now standard for Liquefied Natural Gas (LNG) terminals, an application with rigorous safety demands, and are also increasingly becoming the preferred choice for oil and petrochemical terminals.
“An integrated mooring system brings together all the ‘building blocks’ of state-of-the art mooring within a standard PC-controlled system,” says Simon Wilson, Managing Director of Trelleborg Harbour Marine in Melbourne, which is part of Trelleborg Engineered Systems and a mooring system supplier to about 70 percent of the LNG terminals worldwide. In an integrated system, data from load cells at each hook, docking lasers, hook release control and environmental sensors is communicated to the central PC system. From here, an operator can choose between three different primary display screens: vessel approach, environmental data and mooring line load monitoring. Each of the screens gathers all relevant information for the situation in question. For example, the vessel approach screen provides a graphical image of the vessel as it approaches the jetty from a distance of 200 meters. Speed of approach zones can be set by the jetty operator to warn if the vessel is approaching the jetty too fast at a given distance. The user-friendly PC interface requires minimal operator skills to provide real-time displays and recording of data. If the data from the jetty sensors exceeds the predetermined range limits, the system raises alarms, which can also be communicated to jetty and vessel personnel. This alarm/status interface uses a simple traffic-light color system (green, amber, and red) to feedback alarm status. Corrective action can then be taken to ensure that the approach parameter or line tensions remain within the operational guidelines. “Without this kind of systems integration, an operator would need to monitor more screens and almost certainly learn new software,” says Wilson. “Using different suppliers often leads to problems with the management of spares and potential interfacing problems. The owner also risks losing out on a meaningful system-wide warranty, and in the event of a failure, it is more difficult to ascertain the cause.”
At Harbour Marine, time and technology never stand still.
“It’s important to continuously discover new enhancements to boost safety and performance,” says Wilson. “For example, we are incorporating Global Positioning Systems (GPS) in combination with our SmartDock laser docking to provide electronic piloting assistance during approach and maneuvering, as well as precision monitoring of the vessel’s final speed, distance and angle at the berth. This has particular application for terminals with narrow channel approaches or other access issues.” Mooring system building blocks An integrated mooring and monitoring system may include some, or all, of the following parts:
• Quick release hooks and capstans
• A remote release
• A docking aid system (DAS), which typically consists of two lasers, a central PC with specific software, and a remote display device for each jetty
• Environmental and met-ocean monitoring, which measures the wind, waves and currents affecting the vessel
• Load monitoring of mooring line distribution and tension
• A GPS and AIS-based (Automatic Identification System) piloting system
For more information contact:
[email protected]
www.trelleborg.com