Additional requirements

Vessel operating with alternative fuel source have mandatory class notations given additional rule requirements (Battery Power, FC (fuel cell installation), Gas fuelled LNG, LFL fuelled (low flashpoint liquid) and Gasoline INST, WASP (wind assisted propulsion systems), Gas fuelled LPG and Gas fuelled ammonia. Ships designed for future conversation to an alternative fuel, such as Ammonium can be built with voluntarily class notation Fuel ready. Class notation Fuel for fuel treatment and conditioning systems applies for vessels using residual fuel in diesel engines. //DNV-RU-SHIP Pt.6 Ch.3 Sec.1, Pt.6 Ch.3 Sec.3-5, Pt.6 Ch.3 Sec.7 and Pt.6 Ch.3 Sec.12-14

1.1.1 M/S MERSol operates on marine diesel oil, i.e. requirements for heavy fuel oil don’t apply for M/S MERSol. The vessel has two MDO day tanks and ten MDO storage tanks. There is one fuel oil transfer pump and one separator with feed pump. Transfer pump is fitted with suction strainer, isolating valves and local pressure gauges. It can be used for pumping MDO from storage to storage/day tank and pumping ashore from storage and overflow tanks. Fuel oil separator has suction from selected storage tank and delivery to selected day tank. It is also used for filling emergency generator tank. Both MDO tanks are fitted with high- and low-level alarms, high temperature alarm and drains. The high-level alarm stops separation automatically. Storage tanks are fitted with high- and low-level alarms.
M/S MERSol has two fuel oil circulating pumps (one for each main engine) with duplex type suction strainers, which is sufficient for multi-engine installations. Main engines have also double type manually controlled safety fine filters with high differential pressure alarm in fuel feed line located next to the engine. The engine connections are fitted with dampers and flexible hoses. Each of engines have connections to both day tanks. In addition, there is one common air-driven black-out pump with normal strainer. No by-pass lines are added. All pumps are fitted with emergency stops.
Auxiliary engines have built-on circulation pumps and two filters on each of the engines.
Fuel suction lines from both MDO day tanks are fitted with pneumatic remote controlled quick-closing valves. Feed and return lines from auxiliary engines have both isolation and quick-closing valves located next to the engines. All suction branches for MDO day tanks have quick-closing valves directly on the day tanks.
There are manually controlled MDO coolers in main engine return lines, located on same units as duplex filters and circulating pumps.
As exception of the rules, transfer line from FO7 tank is passing through freshwater tank FW3 inside a pipe tunnel. This kind of arrangement can be accepted as potential leakage from FO pipe will not end up in a freshwater tank.