This text provides an introduction to the theory and design of engineering machinery and equipment aboard ship. Primary emphasis is placed on helping the student acquire an overall view of shipboard engineering plants and an understanding of basic theoretical considerations that underlie the design of machinery and equipment. Details of operation, maintenance, and repair are not included in this text. The text is divided into five major parts. Part I deals with the development of naval ships, ship design and construction, stability and buoyancy of ships, and preventive and corrective damage control. Certain theoretical considerations that apply to virtually all engineering equipment are discussed in part II. Part III takes up the major units of machinery in the main propulsion cycle of the widely used steam turbine propulsion plant. Auxiliary machinery and equipment are discussed in part IV. Other types of propulsion machinery, together with a brief survey of new developments in naval engineering, are considered in part V. In addition to these five major parts, the text includes an appendix which surveys and briefly describes a number of references that should be of value to engineering officers.