Suspension bridge Dynamic load refers to environmental factors that go beyond normal weather conditions, factors such as sudden gusts of wind and earthquakes. All three factors must be taken into consideration when building a bridge. The principles of suspension used on the large scale may also appear in contexts less dramatic than road or rail bridges. Light cable suspension may prove less expensive and seem more elegant for a cycle or footbridge than strong girder supports. An example of this is the Nescio Bridge in the Netherlands. Where such a bridge spans a gap between two buildings, there is no need to
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