Air Lubricated And Air Cavity Ships

Air Lubrication and Air Cavity Technology is a major development that has emerged in recent years as a means to reduce resistance and powering for many types of ships, and an efficient design for high speed marine vessels. This book introduces the mechanisms for boundary layer drag reduction and concepts studied in early research work. Air bubble and sheet lubrication for displacement vessels is outlined and the key projects introduced. Generation of low volume flow air cavities under the hull of displacement, semi displacement and planing vessels are introduced together with theoretical and empirical analysis and design methods. Resistance reduction, power reduction and fuel efficiency are covered for both displacement and high speed vessels. Air layer and air cavity effects on vessel static and dynamic stability are covered, linked to regulatory requirements such as IMO. Seaway motions and reduced impact load of high speed craft in waves are discussed including model test results. Integration of propulsion systems for optimum powering is summarized. A design proposal for a wave piercing air cavity craft is included in an appendix. A comprehensive listing of document resources and internet locations is provided for further research.

Inland Waterway (IW), or river vessels are in every respect different from the seagoing ships. The professional literature is mostly focused on conventional seagoing fleets, leaving a gap in the documentation of design practices for IW vessels. The principal attribute that differentiates river vessels from the seagoing ships is the low, or shallow, draught due to water depth restrictions. This book addresses key aspects for the design of contemporary, shallow draught IW vessels for the transport of dry cargo (containers and bulk cargo). Most of the logic that is presented is applicable to the design of river vessels for any river, but the material that is presented is focused on vessels for the River Danube and its tributaries. The term ‘contemporary river vessel’ assumes that the present-day technology and current Danube river infrastructure are taken into consideration in its design. It is believed that the technologies and concepts that are proposed here are applicable for all new vessel designs for the next 10 to 15 years. Other innovative technologies should be considered for designs beyond that horizon. Moreover, nowadays contemporary IW vessel must be in harmony with the Environmentally Sustainable Transport (EST) policies and hence special attention is paid to both ecology and efficiency. Note however that shipowners and ship operators usually tend to choose the conventional cost-effective transport technologies. Given that potential divergence of interests, the concepts and technologies treated here may be regarded as innovative.

These proceedings contain the papers presented at the 7th International Symposium on Practical Design of Ships and Mobile Units. The symposium was held at the Congress Centre in The Hague, The Netherlands on 20-25 September, 1998.The overall aim of PRADS conferences is to advance the design of ships and mobile marine structures through the exchange of knowledge and the promotion of discussions on relevant topics in the fields of naval architecture and marine and offshore engineering. Greater international co-operation of this kind can help improve design and production methods and so increase the efficiency, economy and safety of ships and mobile units. The main themes of this symposium are design synthesis, production, ship hydromechanics, ship structures and materials and offshore engineering. Some topics which attracted many papers were design loads, design for ultimate strength, impact of safety and environment, grounding and collision, resistance and flow, seakeeping, fatigue considerations and propulsor and propulsion systems.