From the early 19th century until the third quarter of the 20th century, steamships crossed the seven seas, gradually eliminating sailing ships from commercial shipping.
In the second half of the 20th century, the motor ship
started to dominate. The history of the diesel engine
began in 1892 with Rudolf Diesel and twenty years later,
the first four-stroke marine diesel engine ships were operational.
Around 1930, two-stroke designs took a strong lead as
ships became larger and faster. Between World War I and World War II, the share of marine engine-driven ships increased to approximately 25 percent of the overall ocean-going fleet tonnage.
A series of innovations of the diesel engine followed, which made it possible to use heavy fuel oil in medium speed trunk piston engines, pioneered by the MV The Princess of Vancouver. In the mid-1950s, high alkalinity cylinder lubricants became available to neutralize the acids generated by the combustion of high sulphur residual fuels, and wear rates became comparable to those found when using distillate diesel fuel.
Diesel ships using residual fuel oil gained in popularity and in the second half of the 1960s, motor ships overtook steamships, both in terms of numbers, and in gross tonnage. By the start of the 21st century, motor ships accounted for 98 percent of the world fleet.
Marine engines have also found their way into the