Marine propulsion in modern marine engineering is a flourishing technology. There are many ways to generate thrust in order to move a ship (or boat) through the water. These types of marine propulsion systems available vary from the archaic steam engines to reciprocating diesel engines. With the technology burst in the last decade, engineers have focused on creating efficient, economical, and environmentally friendly propulsion systems. This essay will explore the phenomenon of the evolution of the marine propulsion unit and the future of this vital system.
One of the first engines used in marine propulsion was steam. These early engines were replaced by the more lucrative and efficient diesel engines, gas turbines, nuclear reactors, and electronic motors. The ease of operation of the diesel engine (in combination with the turbo charger) makes it the primary mover for most modern day ships. They provide the most simplistic, continuous, and economical option for the majority of companies. Slow speed engines allow for an efficient operation of the propeller at operating speed. These tend to not need gearboxes, it has a direct drive engine. The medium to high speed engine ships utilize reduction gears which enable a wide range of speeds. Also, by using multiple engines to drive the propulsion system, maintenance and repairs can be made while running out to sea. The Navy utilizes gas turbines and nuclear reactors to drive their ships and submarines. Turbines are usually coupled with other engines due to their inefficiency (mainly thermal inefficiency) at idle or low speeds. These reduce emissions, but due to the need for a combination of engines or a combined gas turbine cycle are not as cost effective as the diesel. Nuclear reactor propulsion has been primarily used in Navy ships. A nuclear reaction is created and sustained. The heat created by the reaction is used to create steam and fed to a turbine which, in turn, drives the
References: Rolls Royce. “Kamewa SL-Series Waterjets”. 2012. < http://www.rolls-royce.com/marine/products/propulsors/waterjets/kamewa_sl/index.jsp> Intellijet Marine, Inc. High Tech Water Tech Jet for Energy Conservation”. 200-2012. . Keith Henderson. “World’s First LNG Coaster Nears Completion”. Maritime Propulsion. April 17, 2012. SwanJet. “How Does the Jet Propulsion System Work”. 2008. http://www.swanjet.com/howjetunitswork.html Wikipedia. “Kamewa Waterjets”. March 9, 2012. < http://en.wikipedia.org/wiki/Kamewa_Waterjets> Wikipedia. “Marine Propulsion”. March 29, 2012. < http://en.wikipedia.org/wiki/Marine_propulsion>