Cable-stayed bridge support the bridge deck. Unlike other cable-stayed types, this bridge exerts considerable overturning force upon its foundation and the spar must resist the bending caused by the cables, as the cable forces are not balanced by opposing cables. The spar of this particular bridge forms the gnomon of a large garden sundial. Related bridges by the architect Santiago Calatrava include the Puente de la Mujer (2001), Sundial Bridge (2004), Chords Bridge (2008), and Assut de l'Or Bridge (2008). Cable-stayed bridges with more than three spans involve significantly more challenging designs than do 2-span or 3-span structures. In a 2-span or
Pontoon (boat) boat without much warning, particularly a top-heavy boat. Common boat designs are a catamaran with two hulls, or a trimaran with three hulls. Boats with three hulls are sometimes called "tri-toons." Small inflatable pontoon boats are one or two person, catamaran type boats, designed for leisure and fishing. Their pontoons are made out of abrasion resistant PVC and nylon with aluminum, steel and/or plastic frames for support. In today’s setting, more and more people prefer to use frameless pontoon boats. They are powered with paddles, oars and often with electric trolling motors using deep cycle lead batteries. Commonly they are