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Combining experience and innovation from the shipping and offshore indus- tries has been instrumental in develop- ing Norwegian LNG technologies, and a national propensity for forward-thinking solutions coupled with a collaborative culture suggests a positive future for the industrial economy. In addition to direct resource exploitation to the benefit of domestic energy needs and export earn- ings, including a growing role as a natu- ral gas producer, the skills, expertise and technology developed on the Norwegian continental shelf are being applied to effect worldwide in the oil and gas sec- tors and related businesses.

In the field of energy transportation, new initiatives emanating from Norway include innovative proposals for natural gas containment and handling.

Industrial consortium Compressed

Energy Technology (CETech) has pre- pared new designs of natural gas carrier using the compressed natural gas (CNG) method, as an alternative to transporta- tion in liquefied form, while another, largely Norwegian grouping has drawn up a range of applications based on its pressurized natural gas (PNG) tanker concept.

CETech is a joint endeavor of promi- nent Norwegian organizations Statoil and Leif Hoegh and Vancouver-based

Teekay Shipping, and a project to devel- op and qualify CNG technology has been pursued in recent years in coopera- tion with a prominent classification society. In addition to a pure CNG car- rier (the CNG Shuttle concept), the

CETech consortium has developed pro- posals for a vessel, designated the

Shuttle Producer, which can load both

CNG and oil. Essentially a shuttle tanker incorporating a CNG storage unit, the

Shuttle Producer is currently being offered in two configurations. One is arranged to carry 8,000-cu. m. of gas and 60,000 to 70,000-cu. m. of oil with- in an Aframax hull, and the other is dimensioned for 30,000-cu. m. of gas and 120,000-cu. m. of oil within a

Suezmax hull.

Studies have indicated that CNG tankers could complement LNG carriers and pipelines in certain situations. CNG is considered best suited to moderate or short route lengths, between 300 and 2,000 nautical miles, and where the amount of gas to be transported annual- ly is fairly small, in the range of 500- 3,000-million cu. m. per year. CNG car- riers could also help exploit limited or marginal gas resources that would be uneconomic to transport by other meth- ods.

Gas is loaded at a pressure of 250-bar into banks of long, horizontal cargo 'pipes'. A CNG carrier to transport 100,000-cu m of gas would have a total of 510 cargo containment pipes, fabri- cated from steel. Knutsen OAS Shipping of Haugesund has developed a oncept of pressurized natural gas (PNG) tanker in conjunction with Det Norske Veritas and the German company Europipe. In the

PNG concept, gas is stored under nor- mal temperature in 1,066-mm diameter vertical pipes incorporated into the ship.

No sophisticated processing is needed to maintain the gas in the containment system. Due to operation under ambient temperatures, no insulation will be required to prevent cargo heating during the voyage. PNG offers the potential of reduced capital investment in handling facilities.

Three different types of vessel have been developed, comprising an offshore loading and discharging PNG design of 290 x 54-m main dimensions, a com- bined terminal/offshore vessel, and a larger carrier to undertake long-haul shipments at speeds up to 17.5-knots.

Norway is said to have the second largest gas resources in Europe, after

Russia, and is a major supplier of gas to

European markets, and a growing sup- plier to more distant markets. There are about 50 fields producing gas on the

Norwegian Continental Shelf, and

Norway is the third largest exporter of natural gas, after Russia and Canada. It is reckoned that only about 13-percent of total resources have been produced to date, with only a minimal amount of anticipated resources in the northern- most areas, including the Barents Sea, having been tapped so far. There is accordingly every expecta- tion that Norway has a long-term future as a supplier. 32 Maritime Reporter & Engineering News

NorShipping 2005

An Unerring Drive to Innovate

David Tinsley, technical editor

The prolific output of offshore sup- port vessels from Norway's west coast yards has long been characterized by highly advanced designs, such that the industry truly warrants its ranking as a driver of maritime technology in this demanding sector. However, the efforts of builders to meet the challenges of a market faced with intensifying price competition from eastern Asia and else- where has brought an added dimension to service vessel production, in the form of designs offering the same quality and reliability but more simplicity and lower acquisi- tion cost than the typically very sophis- ticated ship from Norway. Less com- plexity and greater flexibility in techni- cal specification has evidently made for keener prices.

Expression of this pragmatic approach is to be found in two recent completions for U.S. principals. The 65.8-m anchor-handling tug supply vessels Donnelly Tide and Platt Tide have introduced the Aker AH-03 design concept to the Tidewater fleet, provid- ing versatile, workmanlike new capaci- ty for the group's operations in various waters. Following completion by

Soviknes Verft, part of the Aker Yards network, Donnelly Tide was dispatched to duties off Angola, and was followed by Platt Tide from the shipbuilder's

Brattvaag premises. The AH-03 type as embodied in Donnelly Tide and Platt

Tide offers a continuous bollard pull of approximately 100-tonnes and is pow- ered by two nine-cylinder diesels of the compact MaK M25 design manufac- tured in Germany by Caterpillar.

Drive is through reduction gearing to a pair of nozzled, controllable pitch propellers, and the power and lines of the vessel provide for a service speed of around 13-knots, although the maxi- mum speed is about 15-knots. Pivotal to the design's capabilities, the towing winch is of the waterfall type, consist- ing of two de-clutchable, towing/anchor-handling drums. The stern roller has been dimensioned for a 300-ton design load.

In addition to anchor handling and towing, each 2,100-dwt vessel is suited to rig and platform supply operations by virtue of a 1,200-ton deck cargo capacity, plus an array of underdeck tank storage for the liquid and dry bulk consumables that are part-and-parcel of offshore drilling and production needs.

Contributors to the essential properties of maneuverability and station-keeping performance are the twin, high-lift flap rudders and three electrically-driven, 590-kW transverse thrusters, two in the bow and one in the stern. Vessel motions in the often extremely arduous conditions encountered by such work- horses of the offshore industry are less- ened by means of a passive roll reduc- tion system.

Cost-Competitive Anchor Handlers

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