cryogenic engineering
US fast-tracks LNG- powered ships
Orders have been placed for the construction or conversion of 16 US-flag ships to run on LNG while final decisions for twice that number are imminent
by Mike Corkhill T
he shale gas phenomenon in the US has been a game changer for not only the global gas industry but also operators of US-flag vessels. A growing number of the country’s shipping companies are preparing to use the growing supplies of competitively priced, clean-burning gas now becoming available to fuel their ships and achieve unprecedented reductions in vessel operating costs. Natural gas is provided for use as a ship fuel
in the form of LNG and, despite the additional costs
associated with LNG-powered vessels, including the newbuilding premium and the specialist liquefaction plants and bunkering arrangements required, the use of this new fossil fuel is set to pay dividends.
As a result of the growing shale output from deposits across the country, the US has regained its title as the world’s largest producer of gas in recent years. Nationwide gas production reached 2.2 trillion ft3 in August 2013, the highest monthly total since 1973. According to the US Energy Department, output in 2014 is expected to average 71 billion ft3/day, or 1.1 per cent above the 2013 figure.
US consumers are now paying approximately
Wärtsilä 34DF dual-fuel engines for installation on one of the six LNG-powered offshore support vessels building for Harvey Gulf
US$4.25 per million Btu for their gas, about one-third of the price pertaining in Europe and under a quarter of that for gas delivered to Asia as LNG. On a Btu basis natural gas in the USA, after conversion to LNG, also costs less than both heavy fuel oil and distillate oils such as diesel. The other factor driving US interest in LNG
bunkering is the status of North America as an IMO emission control area (ECA). Gas- burning engines comply with all existing and anticipated restrictions on emissions of harmful atmospheric pollutants under both the ECA and global sulphur cap regimes.
The dash for gas in the USA is helping solve the classic chicken-and-egg dilemma that has slowed acceptance of LNG as marine fuel in various parts
of the world. US shipowners are specifying the LNG fuel option both for newbuildings and for conversions of existing vessels, confident that the necessary gas bunkering infrastructure will be in place at the appointed time. For their part, LNG suppliers are prepared to invest in the necessary fuelling arrangements to be part of an emerging shipping segment in which owners are determined to make significant savings in vessel running costs. Their cause is being supported by a range of cryogenic engineering companies that are currently advancing the efficiencies and availability of their small-scale liquefaction plant technology. In addition it will be possible to load LNG for
bunkering purposes at some of the LNG export terminals planned for the USA. Several such facilities are existing import terminals which are being provided with gas liquefaction trains to enable the supply of LNG to both overseas and local customers.
A recent survey by Zeus Development Corp identified 42 LNG-powered vessels currently under development or evaluation for service in North America. The specified projects encompass 17 ferries, 12 tankers and bulk carriers, six offshore service vessels, six container ships and an articulated tug barge. The project portfolio comprises 30 newbuilding vessels and 12 involving converting the power plant on existing vessels. Several ship newbuilding and conversion are
projects The two TOTE newbuildings will be world’s first purpose-built, LNG-propelled box ships
www.mpropulsion.com already underway. The most advanced project features a series of six 5,250 Marine Propulsion I April/May 2014 I 53
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