Marine engines and their impact on the economy, technical efficiency and environment

Commercial shipping industry employs a large number of bulk carriers, crude oil tankers, LNG vessels and mega container vessels. Needless to say these huge vessels would require great magnitude of power to propel them in high seas. More than 85% of these vessels are propelled by large slow speed engines, directly coupled to the propeller. Last decade has observed a considerable development in these large slow speed engines in te1ms of its design, operational safety, maintenance and fuel efficiency. Major engine builders strive to achieve a high level of efficiency on these engines. From the shipowner's point of view, commercial shipping has become highly competitive and there is a dire need to reduce operation and maintenance costs to survive under the present market condition. Here comes the economical aspect of running ships which is a very crucial conunercial factor. The maritin1c regulators led by IMO (International Maritime Organisation) ensure that the marine environment is clean and free from pollutants, which in this case would be controlling of various pollutants discharged from the exhaust funnels of these large marine diesel engines. This paper provides a comprehensive review of the various stages of development of large marine slow speed engines over the past four decades, and the factors that have influenced these developments. However, in the present day context and the near future need to closely look at the commercial aspect of merchant shipping, and specifically address the three big factors; economy, efficiency and environment protection. The paper also analyses the methods available that can address these three factors and what is in store for the maritime engineering world in the future.