Over the years, the ongoing search for enhanced efficiencies – and hence reduced costs – and the need to maintain the industry’s exemplary safety record have been key drivers of technological advances at the LNG ship-shore interface.
Today, the extension of the LNG supply chain into new markets is applying these traditional technology motivators to new engineering realms. Ship-to-ship, ship-to-shore and shore-to-ship cargo transfers in offshore, small-scale distribution and LNG bunkering scenarios have demanded a growing range of technical solutions.
Several new developments impacting LNG cargo and fuel transfers were unveiled at the LNG World Shipping Ship-Shore Interface 2016 conference, held in London on 11-12 May.
UK bunkering solution
Despite the strict controls on the sulphur content of ship exhaust laid down by the North Sea emission-control area (ECA), the UK has been slower to warm to the promise of LNG as marine fuel than most of its northern European neighbours. However, the recent order by Caledonian MacBrayne for two LNG-powered ferries and the bunkering on Teesside by Anthony Veder of two of its dual-fuel chemical gas tankers indicate that change is afoot.
At the Ship-Shore Interface conference, Bernhard Schulte Shipmanagement (BSM) managing director Angus Campbell told delegates about the UK LNG Marine Corridor project, an initiative assessing the nation’s potential demand for LNG as marine fuel as a prelude to building the infrastructure needed.
Led by the Schulte and Babcock groups, the study covers ports from Kirkwall and Scapa Flow in the north to Southampton in the south. Pre-empting the industry’s likely need for a suitable bunkering vessel, the principals have developed a design for a gas-supply vessel (GSV).
The GSV will be able to provide LNG bunker fuel direct to other vessels, from its Type C cargo tanks and will meet the electricity needs of visiting ships in port by means of its gas-fuelled power-generation system. A new targetless reference system developed by the Schulte Group called RangeGuard would support positioning of the GSV alongside large vessels.
The GSV design portfolio encompasses a range of LNG capacities, from 3,500m3 to 13,000m3. A deck-mounted hose-handling crane would enable bunker transfers to receiving vessels with main deck manifolds up to 28m above the waterline.
In recent years many European LNG-receiving terminals, in the face of slack demand for their primary regasification services, have sought to reinvent themselves as multipurpose facilities in an attempt to generate additional revenue streams. They have added road tanker loading bays and provided the means for loading coastal distribution tankers.
Until these terminals install the appropriate shoreside facilities, the ability to load small LNG carriers at major import terminals has fallen to the cargo-handling attributes of the ship itself. Speaking at the Ship-Shore Interface conference, Anthony Veder manager business and fleet development Bjorn van de Weerdhof described the innovative elevated manifolds fitted on the three coastal LNGCs in the company’s gas-carrier fleet to enable them to load at worldscale terminals in Huelva, Zeebrugge and Rotterdam.
Mr van de Weerdhof urged builders of terminals to also “think small” at the design stage. By bearing in mind coastal LNGC requirements like fender position, the direction of mooring hooks, the reach of gangways and loading arm configurations, a terminal can be provided with multipurpose functionality from the outset.
KLAW LNG group technical director Tony Webber also considered the innovations deriving from small-scale developments such as LNG bunkering, supplying remote island power stations, cargo transfers to distribution tankers and LNGC cool-down operations.
The company, which manufactures breakaway couplings, emergency release couplings and other equipment associated with emergency release systems (ERS), has utilised its experience with large-scale LNG ship-to-ship (STS) transfer operations to provide robust and adaptable solutions that meet the requirements of a variety of small-scale applications.
New ERS technology, developed by KLAW with Shell, has provided a comprehensive LNG-transfer system that fully integrates the flexible hose and its associated couplings and shutdown arrangements with the relevant ship and shore-based cargo-handling systems.
The new KLAW/Shell small-scale ERS technology features an integrated programmable logic controller (PLC), continual monitoring and diagnostics of safety-critical systems and the automatic archiving of performance data.
Mr Webber pointed out to delegates that its latest ERS technology is configured to ease the burden placed on crew and shore staff to maintain safety and to maximise the service life of the equipment.
STS performance advances
Exmar Shipmanagement (ESM) global head of marine solutions Sachin Mohan reported on his company’s efforts to integrate STS transfer functions. ESM pioneered regasification vessel operations in 2005 and today manages 10 floating storage and regasification units (FSRUs), the largest such fleet in the world.
At the time of the conference ESM has successfully completed 887 incident-free STS operations, transferring a total 94 million m3 of LNG.
Ship managers responsible for STS operations have traditionally had to work with four to five separate cargo-handling and other shipboard systems during LNG transfers. ESM is working to provide a single process-management solution that integrates all relevant internal functions.
Through the generation and retention of real-time data, the initiative is set to realise efficiency, control, reliability and timesaving gains for the benefit of crews and ESM customers alike.
Trelleborg Marine Systems UK technical director Andrew Stafford described how his company’s SeaTechnik links ship-to-shore communications/emergency shutdown (ESD) systems to facilitate and safeguard the worldwide trade in LNG and LPG.
SeaTechnik ship/shore links (SSLs) are fitted in 625 LNG ships and terminals worldwide. In addition to their ESD initiation capabilities, SSLs handle telecommunications and data transfer between ship and shore. An independent system must be provided to complement the primary link.
A typical SSL incorporates fibre optic and electrical umbilicals, a pneumatic reel, hotlines, telecom lines, modems and associated control boxes and enclosures. Compatibility between the various pieces of equipment that make up an SSL package has caused problems over the years, and backwards compatibility with older devices is a particular concern.
As the leading provider of such systems, Seatechnik is playing a key role in tackling the inconsistencies.
The introduction of new vessel types, such as FSRUs and floating storage units (FSUs), over the past decade has posed challenges, due not least to the dual role of such ships as conventional LNGCs and floating process vessels.
LNG bunkering is a more recent development and Mr Stafford told the Ship-Shore Interface conference delegates that, as yet, there is still no agreed functional requirement for the SSL link to be provided for fuelling of gas-powered ships. In these new markets, regulation is lagging behind innovation when it comes to ship-shore links.
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