Pontoon bridge using a single 'o'. The U.S. military differentiated between the bridge itself ("ponton") and the floats used to provide buoyancy ("pontoon"). The original word was derived from Old French "ponton", from Latin "ponto" ("ferryboat"), from "pons" ("bridge"). When designing a pontoon bridge, the civil engineer must take into consideration the Archimedes' principle: Each pontoon can support a load equal to the mass of the water that it displaces. This load includes the mass of the bridge and the pontoon itself. If the maximum load of a bridge section is exceeded, one or more pontoons become submerged. Flexible connections have to
Navy lighterage pontoon wedge pins. The flotation blocks came in two types: The principal type of unit was a rectangular prism; the majority of NLPs were constructed using these. The second type was similar but curved upward on one side, and these boxes were used to make bows on the front of NLP barges when required. Navy lighterage pontoon The Navy Lighterage pontoon (NLP) was a type of pontoon developed in World War II by the US Navy and used by naval construction teams (Seabees) and specialized US Army combat engineers, on invasion beaches and shallow harbors or harbors where the facilities had