This book presents research results, investigations and field experiences on contact-related behavior of hydraulic closures, such as gates of locks, weirs, movable flood barriers, shipyard and harbor docks. The subject is discussed in an interdisciplinary manner. Presented are design loads, tribological and other phenomena significant for the design and maintenance of gares and their contact components, as well as the impact of those phenomena on the type selection and design processes. The solutions and references originate from the author's experience in engineering, research and management of water related projects, particularly hydraulic gates. Predominate part of this experience was collected in his function of chief engineer for infrastructural projects by the Civil Engineering Department of the Dutch Ministry of Transport, Public Works and Water Management. In addition to the author's own solutions, some latest projects of his colleagues in the Netherlands and abroad have shortly been discusseed. This book is an updated and extended version of the doctoral thesis defended in 2005 on the Gdansk University of Technology.