Z kontekstu wynika statek tankowiec = zbiornikowiec.
Dual fuel diesel electric to dwu-paliwowy napęd (nie silnik) w którego skład najpewniej wchodzi kilka silników (liczba mnoga) tłokowych i w przypadku zbiornikowca do przewozu gazu dodatkowo turbina parowa zasilana parą ze spalania BOG (boil-off gas). W takim układzie może być silnik tłokowy jedno paliwowy (paliwo płynne) i jedno paliwowa turbina (gazowa) - i tak będziemy mieli układ napędowy "dual-fuel".

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Propulsion systems
Most propulsion systems in LNG carriers use the BOG and liquid fuels. In a steam plant, the BOG is used to fire the boilers and produce steam. The steam drives the turbines and propels the ship. The advantage to this type is that when the LNG cargo tank pressure is elevated the excessive BOG is burned simultaneously with liquid fuel. If there isn’t enough BOG, liquid fuel (heavy fuel oil or HFO) is used to keep the plant operating.[2] An alternative to the steam turbine engine is the dual-fuel marine diesel engine. Commercial ship propulsion system manufacturers such as Finland’s Wartsila and Germany’s MAN Diesel SE are producing large bore dual-fuel diesel engines. The MAN B&W ME-GI Engines have extremely flexible fuel modes that range from 95% natural gas to 100% HFO and anywhere in between. A minimum of 5% HFO for pilot oil is required as these are compression ignition engines and natural gas is not self-combustible.