Suspension bridge major wire-cable suspension bridge was the in Philadelphia, Pennsylvania. Designed by Charles Ellet, Jr. and completed in 1842, it had a span of 109 m. Ellet's Niagara Falls Suspension Bridge (1847–48) was abandoned before completion. It was used as scaffolding for John A. Roebling's double decker railroad and carriage bridge (1855). The Otto Beit Bridge (1938–39) was the first modern suspension bridge outside the United States built with parallel wire cables. The main forces in a suspension bridge of any type are tension in the cables and compression in the pillars. Since almost all the force on the pillars is
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