Services
STS Transfer of LNG
Ship-to-ship LNG transfer enables cargo movement between two vessels alongside — either at a terminal berth or in an offshore anchorage. GLSB provides operational planning, equipment specification, and marine coordination across both modes.
Transfer Modes
Two Operating Configurations
Berth-Side Transfer
LNG transfer conducted with both vessels moored alongside at an existing terminal berth. Leverages onshore infrastructure for BOG handling and utilities while enabling efficient cargo splitting or top-up operations.
- Utilises existing terminal safety systems and monitoring
- Shorter hose runs and simpler mooring geometry
- Requires terminal operator approval and SIMOPS clearance
Open-Water Transfer
Transfer carried out in a designated anchorage area, independent of a fixed terminal. Both vessels moor alongside each other using fendering and mooring lines, with transfer via LNG hoses in the open seaway.
- Does not require access to a fixed terminal berth
- Higher demands on fendering, hose specification, and sea-state limits
- Requires designated anchorage with port authority clearance
Technical Detail
Key Technical Considerations
Breast lines, spring lines, and fender arrangement must account for vessel displacement differential, swell, and wind loading throughout the transfer.
Pneumatic or foam-filled fenders selected based on vessel freeboard differential and expected sea states at the transfer location.
Cryogenic-rated flexible hoses with emergency release couplings. Hose management systems prevent kinking and limit tension during vessel movement.
Continuous vaporization during transfer produces boil-off gas. Both vessels must be capable of managing BOG via compressors or vent mast within agreed limits.
Simultaneous operations require coordinated hazard assessment — particularly when transfer occurs alongside an operating terminal with concurrent cargo movements.
Large LNG carriers deliver to a floating hub; smaller coastal vessels take on sub-cargoes for onward distribution to regional import terminals.
GLSB Scope
How We Engage
GLSB provides end-to-end STS operational support — from pre-operation planning and equipment specification through to on-scene marine coordination.
Pre-operation risk assessment, mooring and fender arrangement design, compatibility review between the two vessels.
Hose selection, fender sizing, emergency release coupling specification, and SIMOPS procedure documentation.
On-site superintendence, harbour master liaison, vessel master briefings, and real-time operational oversight.
Plan an STS transfer operation
GLSB provides operational planning, marine coordination, and equipment specification for STS LNG transfer.