All technology topics
Containment
SPB / Self-Supporting Prismatic Type B
Independent prismatic tanks with internal bulkheads that limit free-surface movement of the cargo.
Educational data
Schematic placeholder
Layer 01
Flat tank top and deck space
Layer 02
Prismatic tank shell (primary barrier)
Layer 03
Internal swash bulkheads
Layer 04
Insulation on the tank exterior
Layer 05
Tank supports and hull structure
What it is
- A self-supporting Type B containment system using prismatic tanks that follow the hull form more closely than spheres.
- Internal swash bulkheads limit cargo movement, supporting operation at a wide range of filling levels.
Where it is used
- LNG carriers intended for demanding sea states, and floating production or storage units where flat deck space matters.
Key design characteristics
- Independent tanks with a flat upper surface, leaving usable deck area.
- Internal structure designed to manage sloshing loads.
- Leak-before-failure design philosophy with partial secondary barrier arrangements.
Benefits
- Filling-level flexibility combined with better hull-space use than spherical tanks.
- Flat deck supports topsides equipment on floating infrastructure projects.
Operational considerations
- Fabrication is structurally complex, which affects build scheduling.
- A smaller installed base than membrane systems means fewer reference projects.
Related vessel segments
Related glossary terms
Technical information
- Status
- Educational overview — editorial review required
- Seeded educational summary awaiting editorial and technical review.
- Last reviewed
- 15 September 2026
- Source status
- Sources pending editorial review.
Technical parameters are indicative and may vary by vessel design, generation, shipyard, operator and intended service.