As for the barge design, two versions have been developed, one without propulsion, pushed by a pusher tug, and another self-propelled, integrating a structural block at the stern that includes the propulsion room and the superstructure for the outfitting and the wheelhouse. The propulsion system, with electric engines, is based on a new concept, dual-gas-LNG (GADOG), consisting of two gas generators and a third, dual fuel, which can consume both low-sulphur Marine Diesel Oil and LNG.
The two designed versions have the following characteristics, required to achieve the project needs:
- Capacity to store and supply 600 m3 of LNG, by means of a type-C tank installed on the double bottom of the barge, carrying out the gas supply operations using a transfer arm located on one of its sides.
- Thermal energy transfer capacity, by using the residual heat from gas engine cooling.
- Ability to perform Cold Ironing operations (electrical power supply) to other vessels, using gas generator sets and a cable transfer crane located on the side of the barge.
- In the case of the self-propelled version, liquid fuel supply capacity, such as Marine Diesel Oil.
- Maximum reduction of pollutant gas emissions into the atmosphere, as a result of the use of LNG as a fuel, in all operating conditions. In the case of the unpowered barge, for the LNG supply operation, the own source of electrical energy is a battery rack dimensioned for this purpose.
- Modularity and flexibility to achieve, in the case of an increase in LNG demand or electrical power, double the design capacity through different configurations, being able to use both versions as a barge train.
Regarding the design of the mobile LNG supply system of the Port of Gijón, the design, specifications, P&IDs, risk analysis and layout plans and safety distances of a Multi Truck to Ship (MTTS) system for bunkering from 4 tankers simultaneously have been carried out.