Feature 2 | GAS tANkerS
Feature 2
position, derived from a percentage of the buckling when connecting to loading some of them will last up to 30 years
beam of the ship. Goal-based standards arms • Personnel protection
offered the designer more flexibility, with • Shore power systems and the • Custody transfer systems/filling limits
the requirement being only to demonstrate consequences for safety in the context of • Ambiguous terms and archaic
conclusively that a given tank is able gas carriers terminology
to handle a collision or grounding, in • Containment systems, to include • Regasification systems; guidance
the context of both its location and its insulation systems and testing regarding safety aspects of shipboard
protection by surrounding steelwork. • Gas combustion units regasification plant
• Pressure relief systems, where a working • Cargo sampling systems; to include
Developing agenda group will assess fire hazards related to guidance on pipe connection failures,
The agenda for the first meeting, on 25 LNG carriers, and the size and basing of specifically following on from the
January 2008, comprised the following relief valve designs propane leak occurring onboard
areas of review: • Instrumentation and controls including Ennerdale at the UK’s Fawley terminal
• Gas burning propulsion systems safety aspects of programmable software in October 2006
• Reliquefaction systems systems • Prescriptive style
• Environmental benefits of gas burning in • Emergency shutdown systems
port, and specifically environmentally- • Operational training for LNG and LPG Mr Roue said some consideration
friendly gas burning in the context of carriers, over and above basic STCW would also be given to novel concepts for
restriction placed on such practices by training requirements; this item might gas transportation, including compressed
shoreside authorities also later include an initiative aimed at natural gas and hydrates, with some
• Hazardous area classification in continuous training requirements for members of the steering group having a
terminals, where the IEC will take a steam turbine-powered ships. Despite keen interest in such matters, although
lead moves to dual fuel and slow-speed diesel he emphasised that the Code would
• Manifold strength, where there have on newer ships, 250 ships remain in predominantly remain focused on liquefied
been cases of LPG carrier manifolds service propelled by steam turbines, and transportation. NA
Qatargas considers engine switch
Charterer Qatargas is considering modifying the propulsion of up to 32
liquefied natural gas carriers, seven of which have already been delivered,
in response to soaring bunker fuel oil prices.
I
nternal discussions are continuing been based was no longer sustainable, added: ‘If we can make economic sense of
at Qatargas over the possibility with fuel oil prices unlikely to drop this, we will go for it.’
of modifying slow-speed diesel below their current levels of $470-$480 When first ordered, the low-speed
engines installed or to be installed per tonne. diesel engine option, operating in
aboard up to 32 LNG carriers, all of He said Qatargas had been in combination with reliquefaction plant,
which are above 200,000m
3
capacity, so discussion with MAN Diesel over a offered significant efficiency gains over
that they are equipped for gas injection. possible modification project and that steam turbines. At that time, it was also
The move, which a Qatargas source the engine builder had subsequently contended that charterers would prefer
suggested would cost up to €50 million approached the three shipyards to burn diesel and deliver as much
per ship, would involve adapting the twin constructing the carriers – Samsung LNG as possible. Since then, the rise in
6S70ME-C electronically-controlled, Heavy, Daewoo Shipbuilding and diesel oil prices has undermined such
low-speed diesel engines from MAN Marine Engineering, and Hyundai thinking, while it is also understood
Diesel installed on each ship so that Heavy – to explore the consequences of that issues have emerged over diesel oil
they can burn LNG. This would involve such a plan. Qatargas was now awaiting bunkering per se.
changing the engines’ cylinder heads feedback from the shipbuilders. Ships so far delivered for Qatargas,
and compression housing, as well as the all of the Q-Flex type, have come under
introduction of a new fuel system. economic sense? the ownership of Overseas Shipholding
The Qatargas source said that the The Qatargas source emphasised that no Group and Pronav. It is understood
original cost model upon which the firm decision had been arrived at over the that owners are awaiting feedback from
selection of low-speed diesel engines had propulsion system change. However, he Qatargas on its deliberations. NA
52 The Naval Architect February 2008
NA Feb 08 - p50+
52.indd 52 05/02/2008 09:40:13
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