Lng_carrier

LNG carrier is a ship designed for transporting liquefied natural gas (LNG). As the LNG market grows rapidly, the fleet of LNG carriers continues to experience tremendous growth.

LNG Carriers under construction at DSME shipyard, Okpo

Contents 1 History 2 New building 3 Containment systems 3.1 Moss tanks 3.2 IHI 3.3 TGZ Mark III 3.4 GT96 4 See also 5 External links

History

Diagram of newbuilding rate.

The first ship Methane Princess was taken into operation in 1964 and remained in operation until 1998 when it was scrapped. Until the end of 2005 a total of 203 vessels has been built and only 10 of them have yet been scrapped.

New building

At the moment there is a boom in the fleet as there is a total of more than 140 vessels on order at the worlds ship yards. Today the majority of the new buildings are in the size of 120,000 m³ to 140,000 m³. But there are orders for ships with capacity up to 260,000 m³.

Containment systems

Today there are four containment systems in use for new buildings. Two of the designs are of the self supporting type, while the other two are of the membrane type and today the patents are owned by Gaz Transport & Technigaz\'s (GT&T).

There is a trend towards the use of the two different membrane types instead of the self supporting storage systems. This is most likely due to the fact that the investment required by the shipyards lower.

When transporting natural gas the gas is cooled down to approximately -163 degree Celsius where it will condense to a liquid kept at atmospheric pressure. The tanks onboard the LNG carriers will in fact function as a big thermos where the liquid will be boiling during the voyage. If the gas was not let out of the tank the pressure would slowly build up.

Moss tanks

This design is owned by the Norwegian company Moss Maritime and it is a spherical aluminum tank.

IHI

Ishikawajima-Harima Heavy Industries has developed a self supporting tank type. This tank type is very similar to the ones used on the first ship, Methane Princess. The tank is made of aluminum

TGZ Mark III

This design is originally by Technigaz and it is of the membrane type. The membrane consists of stainless steel with \'waffles\' to absorb the thermal contraction when the tank is cooled down.

GT96

This is Gaz Transport\'s tank design. The tanks consists of a primary and secondary thin membrane made of the material Invar which has almost no thermal contraction. The insulation is made out of plywood boxes filled with perlite.

See also

Nautical Portal

• List of tankers

External links

• LNG carriers on order or under construction

This article is licensed under the GNU Free Documentation License. It uses material from Wikipedia