SEEKING A STEP CHANGE
IN LNG CARRIER EFFICIENCY
While major advances have been made in fuel efficiency of LNG carriers there is still much that can be done to reduce consumption. BG Brasil (now, a Royal Dutch Shell plc. subsidiary company) teamed up with Bureau Veritas and its subsidiary HydrOcean, containment manufacturer GTT and UFRJ (Federal University of Rio de Janeiro) to seek ways to reduce even further the fuel consumption of the Lake Charles 174,000 cu m LNG carrier class. The project took a fresh look at every aspect of an LNG carrier design, including hull form optimisation in calm water and in waves, tank arrangement, machinery architecture, propeller and rudder design.
The optimisation process was performed using state-of-the-art CFD (Computational Fluid Dynamics) tools. More than 200 hull forms were evaluated leading to more than 2000 CFD simulations using multi-processor parallel computing.
The project led to a new bow design which provides impressive performance in both calm water and waves. A new hybrid geometry for the No. 1 cargo tank was suggested, which combines two existing technologies, cylindrical and trapezoidal tanks. The possibility of installing a 2,500 cu m heel tank for self-cool-down and gas-up operations as well as for operation within SECA/ NECA zones was investigated. The heel tank would be a GTT membrane tank with MARVS of 2barg that could operate at any filling level.
Jose Ferrari, Technology Manager, BG Group, says, “Collaboration between team members was a key element in the success of the project. The ability and skills in advanced hydrodynamics and integrated ship design were paramount to the successful achievement of project objectives and the delivery of business value.”
Bureau Veritas’ SEECAT (Ship Energy Efficiency Calculation and Analysis Tool) was used for the assessment of energy efficiency. Overall, the optimised vessel presented a performance around 11 per cent better than an existing ship used for comparison purposes.
Although the optimised hull is not directly comparable to the current 174,000 cu m LNG ship designs currently available in the Far East yards, the proposed hull form is very competitive. Based on the feedback obtained from key shipyards, additional work is required to refine further the design and will focus on the optimisation of ship particulars and ship´s aft body.
Moss-type FSU conversion
Bureau Veritas recently worked with Bumi Armada Berhad on the conversion of a 5-sphere 125,000 cu m MOSS-type LNG carrier to a Floating Storage Unit which will provide gas to a power utility company in Malta.
The BV-classed conversion is currently ongoing in a Singapore shipyard and is expected to be completed in the 3rd quarter of 2016.
Bureau Veritas’ consulting arm, Tecnitas, provided an initial assessment, survey and renewal evaluation programme using BV’s HLC software prior to the acquisition. Following acquisition by the client, a thorough structural assessment was performed including a complete ship model Finite Element Analysis to assess and evaluate the capacity of the hull to undergo a second life of twenty years on station. A final steel renewal plan and steel reinforcements were devised.
CO2 EMISSIONS MONITORING
From August 2017 shipping companies with vessels trading to EU ports need to comply with new EU regulations on the monitoring, reporting and verification of CO2 emissions. Initially they have to submit ship-specific monitoring plans to verifiers for approval by the end of August 2017, with per-voyage monitoring set to start on January 1, 2018.
The EU Regulation on the Monitoring, Reporting and Verification of CO2 emissions from maritime transport (EU 2015/757) (MRV Regulation) lays down rules for the accurate monitoring, reporting and verification of CO2 emissions and other relevant information from ships above 5,000 GT calling at EU ports.
Article 4 of the EU MRV contains the principles and Article 5 together with Annex I contain the methods for monitoring and reporting CO2 emissions and other relevant information on maritime transport. Annex II contains rules on the monitoring of other relevant information including distance travelled, time spent at sea and cargo carried (for passenger, ro-ro and container ships).
Each year the company with responsibility for the ship's operations has to report the results of the previous year's annual monitoring of aggregated CO2 emissions. The Monitoring Plan lays down the detailed monitoring rules to be followed when monitoring the CO2 emissions and other relevant information for a specific ship. Regular and at least annual checks of the MP are required to ensure that it reflects the nature and functioning of the ship.
Tecnitas provides a portfolio of services linked to emissions monitoring, including continuous emissions monitoring, e-tool E2 for computation of emissions and preparation of the Monitoring Plan.
News in brief...
Bureau Veritas has been chosen to class a new 180,000 cu m LNG carrier to be built at Korea’s DSME for delivery to Mitsui O.S.K. Lines in 2018. The ship will be propelled by two XDF 72 2-stroke low pressure dual-fuel engines and will have four NO96 GTT cargo tanks.
Bureau Veritas will play a significant role in the LNG18 conference. The “Application of CFD for sloshing assessment” will be presented by Louis Diebold. “Striving for the next step change in LNG carrier efficiency – impact of cargo tank shape on hull performance” will be delivered by Michael DAVISON of BG, with Bureau Veritas participation.
Geogas takes LPG carrier
Courtesy of Geogas
French Geogas Maritime has taken delivery of the 84,000 cu m Champlain LPG carrier built to BV class. It will be shortly followed by her sistership Pointis. The ship is a fully refrigerated vessel with Type A independent tanks built by Hyundai Samho.
Ethane carrier delivered
Courtesy of Evergas
The fourth of an eight ship series of innovative ethane carriers has been recently delivered with BV class by Sinopacific Shipyard to Denmark’s Evergas. JS Ineos Inspiration is a 27,500 cu m multi-purpose gas carrier built for the liquefied ethane trade between US and Europe. The ship's engines are able to run on LNG, ethane and diesel.