The idea behind the LNT A-BOX® was to develop and commercialize a simple and efficient cargo containment system that could enable more shipyards to build LNG carriers at a reasonable cost. The LNT A-BOX® containment system offers a self-supporting prismatic IMO independent type A tank, placed in an insulated cargo hold with a full secondary barrier. The design is based on decades of experience from LPG and LNG carriers, and proven design principles and technologies, but in a new configuration to fulfill the highest standards available.
LNT A-BOX® offers:
- Robust and self-supporting tank – sloshing mitigated
- Insulation with optimal thermal properties
- Full visual condition monitoring of all barriers
- Excellent volume utilization and flexible hull design
Self-supporting prismatic tanks is a proven and reliable technology – it has been successfully used for more than 50 years in the seaborne transportation of liquefied gas. Internal structure and bulkheads inside the tanks curb movements of the liquid, eliminating sloshing problems regardless of the liquid levels in the tanks. Furthermore, the solid tank framework structure prevents vacuum problems in the tanks, simplifying pressure control and cargo handling work. IMO independent tank type A is based classical ship structural design and construction procedures in accordance with recognized standards.
The thermal insulation with the secondary barrier is moved to the inner hull to facilitate visual access of the secondary barrier system, including support structures and tank shell. The hold space is protected from sloshing loads, allowing arrangement of a flexible cold insulation system with outstanding thermal properties.
The independent tank supported by the hull structure prevents the insulated hold spaces from extensive sloshing impulses, allowing the use of insulation materials with outstanding thermal properties.
Avoidance of sloshing loads allows simplified corner panel geometries enabling more volume efficient and slender hull forms for improved transportation efficiency. The thickness of the insulation system can easily be adjusted to achieve the required boil-off rates.