
Though not very common dual fuel marine engines are specifically built to be able to run on two or so different types of fuels, these engines are slightly differently built to be able to run on these different fuels that have different combustion levels some requiring high compression while others being highly flammable to deliver the required force than is harnessed from the engine.
The dual fuel marine engines are used even today but they are mostly constrained to military equipment. The idea of having duel fuels engines installed in to vehicles began in the early 1900’s during the world wars; military vehicles had to be able to run on any kind of fuel they got. Most military equipment had duel fuel engines including some of the marine vessels. The duel fuel engine were mostly installed on smaller vessel that had to deliver troops and equipment to the shores of hostile territory and they had to be able to use whist so ever fuel they found to get back in-case their fuel ran out. Jeeps, trucks and tanks also had duel fuel engines that ran on most fuels since refueling during war was a major problem that required troops to fuel using any fuel available and maintain or advance the front lines.
The idea was successful and maintains its presence within the military vehicles as of today. Dual fuel marine engines are used only on attack vessels or vessel that approaches the hot spots of hostile regions. They do not prefer to use whatsoever fuel but must be prepared to make use of whichever fuel available if required. The engines are specially built to be able to withstand the pressures exerted by different fuel types. These pressures are high depending on the fuel and many normal engines cannot withstand these pressures over long periods.
The 21 century has seem a different king of

Cylinderdual fuel marine engines enter the market, no longer constraint to the military and created to reduce air pollution and fuel costs, usage of LNG or Liquid Natural Gas. It idea of converting engines from normal fuels like petrol and diesel has been encouraged to reduce carbon emissions and was first introduced on automobiles. The idea was a marvel since the LNG conversion required very little modification to the original engine something that could be done in a day.
The idea has been adopted by many small and fishing vessel owners in developing countries who have also converted to these duel fuel marine engines.
Some manufacturers manufacture duel fuel marine engines but the majority of the engines have been noted to be converted by small vessel owners who are aiming to reduce fuel cost. Critique maintain the engines are unsuitable for commercial or private marine vessel since the reduce power on the vessel but the determination of vessel owners to reduce ever rising fuel costs may be difficult to deter.
Today the definition of dual fuel marine engines has changed from the past when it sounded like something from science fiction but with conversion of automobile and truck engines the way has been paved for small marine vessel to also venture commercially in to the duel fuel marine engines.