THE LNG
CUSTOMER SUPPOR T
CREDIT: BERGEN TANKERS
MAKEOVER
Time – the
biggest challenge
“The biggest challenge of this or
any other retrofit is the amount of
time available to complete all the
work required,” says Sølve Bratland,
Commissioning Project Manager.
“The old systems must be removed
and replaced with the new, then
integrating and commissioning them
must be completed against tight
deadlines. A particular challenge
– and source of satisfaction – was
connecting the new technology
to the legacy systems on board, so
they all work together seamlessly.
At Rolls-Royce, we have a strong
engineering community with
significant knowledge and experience
of integrating such complex systems.”
It’s not only new builds that can benefit from using
LNG as a marine fuel. A retrofitting service from
Rolls-Royce can deliver the same economic and
environmental benefits to existing vessels
I
n June 2015, Bergen Viking returned
to service following a successful
retrofit to convert the vessel from
diesel-electric to LNG-electric
propulsion. John Knudsen, President,
Commercial Marine, says: “The Bergen
Viking project demonstrates that LNG
is an option not just for new vessels,
but can be successfully retrofitted into
existing ships to deliver significant
economic and environmental benefits
for owners.”
Bergen Viking is a 95m chemical and
product tanker, supplying diesel and
petrol along the Norwegian coastline.
Delivered in 2007, it is part of a total
fleet of six vessels owned by Bergen
Tankers AS.
The retrofit replaced four of the
ship’s original six diesel generator
sets with two Bergen 26:33L6AG gas
gensets, one in each of the ship’s port
and starboard engine rooms. Each
Bergen engine, rated at 1,460kW,
delivers sufficient power to replace
three of the ship’s original diesel
gensets, but two were retained, one in
each engine room to provide auxiliary/
emergency power.
The engines supply power to all
the ship’s electrical equipment, as
well as propulsion. There is a 900kW
electric motor on each propeller shaft
and a smaller motor powers the
bow thruster.
ferries, tugs and offshore support
vessels. The first engines using LNG
entered service in 2006 powering
doubled-end car ferries.
LNG reduces nitrogen oxide (NOx)
emissions by about 90 per cent while
sulphur oxide (SOx) and particulates
emissions are negligible. LNG engines
also reduce CO2 emissions by 25 to
30 per cent in general, compared
with diesel or heavy fuel oil powered
vessels. Emissions from Rolls-Royce gas
engines are already within the limits
of International Maritime Organisation
(IMO) Tier III environmental legislation,
due to come into force in 2016.
Emissions reduction is important to
Kjell Olav Haugland, Managing Director
of Bergen Tankers. “Our fleet sails along
the long and beautiful Norwegian
coast, and visits several ports every
day, therefore reducing emissions is an
obligation we take very seriously,” he
says. “With Bergen Viking returning to
service now LNG powered, we are also
looking forward to significant savings
in operational costs.”
The power of LNG
“OUR FLEET SAILS ALONG THE LONG
AND BEAUTIFUL NORWEGIAN COAST,
THEREFORE REDUCING EMISSIONS IS AN
OBLIGATION WE TAKE VERY SERIOUSLY”
LNG is growing in popularity as a
marine fuel, and to date Rolls-Royce
has delivered a total of 63 LNG engines
to a range of ship types, including
coastal cargo ships, tankers, cruise
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Efficient
Cost savings can result from the
highly efficient nature of the Bergen
lean burn gas engines, which turn
around 50 per cent of the energy in
the fuel into power at the flywheel.
training courses on products and
associated control and automation
systems help customers optimise
their operations.
Worldwide experience
ABOVE: The LNG gas
tanks on the deck of
Bergen Viking during
the final stages of its
retrofit.
The engines’ lean burn combustion
technology is also very robust and
ensures they can operate on a wide
range of gas qualities.
Efficiency does not come at the
expense of power. Bergen gas engines
are as responsive as their diesel
counterparts. Variable turbocharger
geometry responds quickly to throttle
changes, delivering the torque
necessary to meet the increased
power demand, and fuel efficiency
throughout the power range.
Engine rooms on gas-powered
vessels also stay much cleaner,
saving operators’ time and money by
reducing the frequency of cleaning
tasks and the cost of chemicals. Crews
also appreciate the clean, safe working
environment.
Rolls-Royce also supplied Bergen
Viking’s LNG fuel containment system
and the control and safety system.
Two 155m³ LNG tanks store the fuel
ABOVE: A threedimensional view of
where the LNG gas
tanks are situated on
board Bergen Viking.
and are approximately 18m long and
6m high. They are mounted on each
side of the deck towards the bow
in the only space available. The LNG
fuel containment system and control
system are configured for redundant
propulsion, with crossover options
both on bunkering and supply lines.
Bunkering LNG should be possible
as part of Bergen Viking’s normal
operating routine, with refuelling
required about every three weeks.
Crew training is a key part of every
Rolls-Royce LNG installation, to get
the best out of the new systems and
operate the vessel safely. A range of
Bergen engines fuelled solely by
natural gas have been in production
since 1991 and have completed more
than 25 million hours of operation,
with one million at sea. Since the
introduction of Bergen Engines lean
burn technology, more than 650
gas engines havebeen delivered.
Recent contracts include a
collaboration agreement with
Spanish energy company Gas
Natural Fenosa to develop and
install a Bergen C26:33L6AG gas
genset on the Baleària-operated ropax
ferry Abel Matutes. The contract gives
Rolls-Royce its first reference for a
pure-gas engine installation on a
European-flagged ferry operating
outside of Norwegian waters.
In Singapore, Keppel Shipyard has
ordered two Bergen B35:40V20AG
gas engines for power generation on
board a Floating Liquefaction Vessel
(FLNGV) owned by Golar LNG Ltd.
The vessel Hilli was a former LNG
carrier and is being converted to a
FLNGV carrier.
The contract includes an option for
an additional two engines for a second
Golar LNG carrier to be converted. SK
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