In February 2007 the first LNG shipment arr ived at the newly constructed Teeside receiving terminal in Teesport, UK. Originally an unused jetty that had been built to accommodate crude carriers making deliveries to a nearby refinery, the complete upgrading of the facility means that the terminal can now accommodate LNG carriers that have regasified facilities onboard.
This is a milestone in the LNG industry as it is the world’s first regasification plant, which means that the LNG can be vaporised on-ship and fed at high pressure directly into the national grid network. In order to minimise the possibility of an environmental incident, the refurbished jetty has been fitted with a number of systems that ensure the safe berthing and mooring of a vessel. These Strainstall designed and developed systems and components utilise the latest technology combined with known durability.
Speed of approach
Strainstall’s DockAlert system provides protection of the jetty infrastructure by calculating the vessel approach speed to ensure that it is kept within the allowable limits for the jetty’s safe operation. The system uses two eye safe laser units installed on either side of the jetty head and aimed perpendicular to the berthing line. These measure the distance of the bow and stern relative to the jetty, while also providing speed and relative angle of the vessel to the berth. The data from these lasers is fed into a central control system, where it is displayed in the jetty control room and relayed to a large digit display mounted on the jetty and to PDA’s onboard the vessel.
The large digit display is visible from over 200 m and provides the pilot and vessel master with information on the speed of approach and distance from the jetty. Incorporated in the display are arrows indicating whether the vessel’s speed is increasing or decreasing and simple traffic light indicators to warn against excessive speed. These units can be set against safe parameters to ensure a smooth and gentle berth.
Mooring load monitoring
Strainstall’s MoorAlert system obtains tension inputs on each mooring line from 16 load measuring pins that are designed and installed into quick release hooks. This provides constant real time monitoring of the loads they are being subjected to. Strainstall has been designing and manufacturing these load measuring pins for over 40 years, and the design utilises the almost unique experience gained over this period to provide a reliable and totally environmentally sealed unit that will perform unhindered over the life of the installation.
The signals from the load pins, together with the hook status sensors (open or closed), are consolidated by a network interface unit mounted in the hook motor starter
enclosure, situated to the rear of the hook base. This unit allows the digital signals from all the hooks (in this case two doubles and four triples, making a total of 16 hooks) to be transmitted over a simple two-wire loop system back to the jetty control room.