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) Pontoon (boat) A pontoon boat is a flattish boat that relies on pontoons to float. These pontoons (also called "tubes") contain a lot of reserve buoyancy and allow designers to create massive deck plans fitted with all sorts of accommodations, such as expansive lounge areas, stand-up bars, and sun pads. Better tube design has also allowed builders to put ever-increasing amounts of horsepower on the stern. Pontoon boat drafts may be as shallow as eight inches, which reduces risk of running aground and underwater damage. The pontoon effect is when a large force applied to the side capsizes a pontoon