Essential reading: SPINČIĆ, A., An English Textbook For Marine Engineers I., Pomorski fakultet, Rijeka LUZER, J., SPINČIĆ, A., Gramatička vježbenica engleskog jezika za pomorce, Pomorski fakultet, Rijeka Tomislav Skračić, MA Undergraduate English Course for MARINE ENGINEERS 2nd Semester

KEY WORDS a fairly wide range- poprilično širok izbor / raspon in regular use- u redovitoj uporabi in the course of years- tijekom godina improve (v.)- poboljšati modern refinements- moderna poboljšanja re-heat cycle- krug dogorjevanja superheat (n.)- pregrijavanje obsolete- zastario, napušten supersede (v.)- istisnuti, zamijeniti piston rod - stapajica / klipnjača crankshaft - koljenasto vratilo, radilica SHIP PROPULSION – Part 2 Types of engines

KEY WORDS throughout their operation- za vrijeme rada smoothness (n.)- mirnoća, miran rad (bez vibracija) reliability (n.)- pouzdanost application (n.)- primjena coupled to the shaft- spojen / prikopčan na osovinu gas turbine- plinska turbina steam turbine- parna turbina free piston engine- motor bez klipa (npr. turbina) naval craft- ratni brod / plovilo nowadays- u današnje vrijeme decline (v.)- opadati as yet- do sada SHIP PROPULSION – Part 2 Types of engines

STEAM RECIPROCATING ENGINE SHIP PROPULSION – Part 2 Types of engines

STEAM RECIPROCATING ENGINE

In the steam reciprocating engine, the up and down movement of pistons is converted into rotary movement by piston rods and crankshaft. The steam reciprocating engine, the oldest form of mechanical propulsion, was in regular use for almost two hundred years. In the course of years the machinery was improved and developed compared to its original version, but even with modern refinements, such as superheat and re-heat cycle, the steam reciprocating engine has become obsolete. The steam propulsion has been superseded by the steam turbine. SHIP PROPULSION – Part 2 Types of engines

STEAM TURBINE Steam turbines rotate through their operation. They are often the first choice for very large main propulsion units due to: their smoothness (little or no vibration), low weight, minimum space requirements, reliability, low maintenance costs. Steam turbines have found aplication for the propulsion of most supertankers, some fast passenger liners and fast cargo liners such as container ships. SHIP PROPULSION – Part 2 Types of engines

ADVANTAGES of the steam turbine propulsion If compared to reciprocating engines, steam turbines offer the following advantages: they are smaller in size, they have better power output, compared to any type of reciprocating engines of the same size, require less auxiliaries such as pumps, purifiers... are cheaper to build and install, maintenance costs are up to 60% less, no vibration. SHIP PROPULSION – Part 2 Types of engines

dual-fuel steam turbine propulsion

DIESEL-ELECTRIC OR TURBO-ELECTRIC DRIVE A number of ships have also been built with diesel-electric or turbo-electric drive. In these ships the power units (steam or diesel) are not used to drive the propellers directly, but to generate electricity for driving the motor coupled to the shaft. These units have greater flexibility, but against this must be set the increased costs of installation, maintenance and operation. SHIP PROPULSION – Part 2 Types of engines

gas turbine

gas turbine installation

GAS TURBINE and NUCLEAR POWER Gas turbine and free piston engines have been used for some merchant ships and naval craft. Nuclear power has proved to be, as yet, an uneconomical method of ship drive. Nowadays, the popularity of nuclear power for marine as well as for ashore application is declining. Nuclear power propulsion units can be found in naval submarines, aircraft carriers and Russian ice-breakers. SHIP PROPULSION – Part 2 Types of engines

1.What is the oldest form of mechanical marine propulsion? 2.How long was it in use? 3.Is the reciprocating steam engine still used for ship propulsion? Explain. 4.What advantages do steam turbines offer if compared to reciprocating engines? 5.What offsets the steam turbine advantages when compared with a diesel engine? 6.State the advantages and the disadvantages of the electric drive. 7.Why haven’t gas turbines, free piston engines and nuclear power found a wide application on merchant vessel? SHIP PROPULSION – Part 2 Answer the following questions:

What types of ships make use of the following propelling units? a) Steam turbine b) Gas turbine c) Nuclear power d) Two-stroke slow-speed diesel engine SHIP PROPULSION – Part 2 Answer the following question: