Chapter 3 - Steam turbines and gearing

Abstract

This chapter discusses steam turbines and gearing as related to ships. The steam turbine has until recently been the first choice for very large power main propulsion units. Its advantages are little or no vibration, low weight, minimal space requirements and low maintenance costs. Furthermore, a turbine can be provided for any power rating likely to be required for marine propulsion. However, the higher specific fuel consumption when compared with a diesel engine offsets these advantages. The steam turbine is a device for obtaining mechanical work from the energy stored in steam. The chapter discusses the basic principle of a steam turbine and the types of turbines. It also describes gearing and various other aspects such as astern arrangements etc. The author uses various figures throughout the chapter for a better clarity in illustrating the designs and features. The last section of the chapter discusses the operating procedures of a steam turbine. The steam turbine requires a considerable period for warming-through prior to any maneuvering taking place. The high-speed operation of the turbine and its simply supported rotor also require great care during maneuvering operations.