JUNE 10, 2013 — Bunker barges able to deliver LNG in the volumes required by large oceangoing ships have been seen as a limiting factor in the development of LNG as a marine fuel. According to Vear, Norway, headquartered NLI Solutions, only one LNG bunkering barge exists, capable of delivering 187 cu.m. of LNG, compared to the several thousand cu.m needed by oceangoing ships.
Now NLI Solutions has developed a concept for a 4,000 cu.m LNG bunker barge. It is based around NLI's own LNG tank design and has been further developed in a design study together with the Marine division of Rolls-Royce and Wilhelmsen Technical Solutions (WTS).
"Building a small carrier for bunker purposes is expensive so our suggestion is a high-tech low cost barge, the HighTechBarge (HTB)," says NLI Solutions.
The HTB will for safety reasons be very maneuverable with pod-drives, as is used in offshore support vessels, have state-of-the-art electronics for danger detection and early evasive maneuvering.
The NLI LNG tank is an atmospheric, prismatic steel tank, type "B", in this study capable of containing 4,000 cu.m of LNG. It will be covered with a new insulation system with very low levels of boil off gas (BOG).
As re-condensation equipment is expensive, takes a lot of space, and has a low efficiency for small installations, the BOG that is produced will be used to fuel the barge's own engine and produce electrical power for both propulsion and all barge and LNG/gas systems. is of course from a clean burning gas engine.
The HTB has a large pressure tank on the aft deck for BOG handling and gas delivery to engine. If the HTB has long periods without activity (bunker customers), excess BOG can be delivered to a shore side gas grid, or the barge can deliver electric power to a shore side electric grid.
The study has been carried out and planned with:
Rolls-Royce NVC, responsible for design, Bergen gas engine, pod drives and bridge systems
TI Marine Contracting (part of WTS) responsible for insulation systems
NLI responsible for tank, LNG/gas systems, bunkering systems
The design challenges existing class regulations and codes, and DNV has participated in looking at limitations and possibilities in this area.
High-Tech LNG Bunker Barge - HTB
LOA 63 m
B MAX 20 m,
DEADWEIGHT abt. 2,000 T
Service speed 8 knots
LNG tank capacity 4,000 cu.m,
CNG tank for compressed BOG 270 cu.m
Aft deck contains compressors, vaporizers etc. Bunkering operations from tank top. Main engine and gen-set, size pending operation: Bergen C26:33 gas engine; Bergen C gas engines are available with powers from 1,440 kW to 2,430 kW.