Download - Lng vessels
SHIP DESIGN DEVELOPMENT
Vessel Type Typical Size(Cubic metre) Typical Length(Metre)
Small scale LNG 0-36000 137
Medium scale LNG 36000-90000 260
Lower Conventional LNG 90000-145000 277
Upper Conventional LNG 145000-209000 290
Q-flex LNG 209000-220000 315
Q-max LNG 220000+ 345
Types of Carriers
• Self-supporting LNG carrier - Moss tanks (Spherical IMO type B LNG tanks) - IHI (Prismatic IMO type B LNG tanks)• Membrane tank LNG carrier - TGZ Mark III - GTT 96
Moss Tanks(Moss Maritime)
• Moss type vessels have 4 or 5 tanks.• Checked at 3 month intervals for any cold spots
that would indicate breakdown in the insulation.• Tanks normally have a working pressure of up to
22 kPa (3.2 psi)-(raised for an emergency discharge)
• If both main pump fails, then the tank's safety valves are adjusted to lift cargo at 1bar.
IHI (Prismatic IMO type B LNG tanks)• Designed by Ishikawajima-Harima Heavy
Industries.• limit sloshing problems, an improvement over
Membrane LNG carrier tanks which may break due to sloshing impact, therefore
destroying the ship's hull. This is also of prime relevance for FPSO LNG (or FLNG).