Wind engineering of a two bladed turbine when the blades are vertical. The reduced wind gradient over water means shorter and less expensive wind turbine towers can be used in shallow seas. For wind turbine engineering, wind speed variation with height is often approximated using a power law: where: The knowledge of wind engineering is used to analyze and design all high rise buildings, cable suspension bridges and cable-stayed bridges, electricity transmission towers and telecommunication towers and all other types of towers and chimneys. The wind load is the dominant load in the analysis of many tall buildings. So wind engineering is
Pontoon (boat) of the world, especially in Africa. Pontoon ferries may be motorised, such as the Kazungula Ferry across the Zambezi River, or powered by another boat, or pulled by cables. A type of ferry known as the cable ferry ("punts" was what they were called in the medieval times and in modern Australia and New Zealand) pull themselves across a river using a motor or human power applied to the cable, which also guides the pontoon. Pontoons may support a platform, creating a raft. A raft supporting a house-like structure is a houseboat. The flotation tubes of rigid-hulled inflatable boats are