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A pratt truss bridge design includes vertical components and diagonals that slope down towards the center. It was invented in 1844 by Thomas and Caleb Pratt. It was a common solution for railroad bridges when wood truss elements were replaced for metal. Here you can learn more about its history, its basic capabilities, and some of its most famous bridges that use it.
One of the first modern bridges to be made were truss bridges. They could be made of wood which some places had plethora and could withstand larger weights. They were later made of iron and steel. Many of those old modern bridges still stand.
Over the last 3000 years, engineers and architects have devised many ways of building bridges. Here you can see for yourself bridge types that are in use today, from what materials they are made, and for what uses are they built.
A viaduct is a bridge composed of a series of spans or arches that carries a road or a railway across a valley or a gorge. A viaduct usually refers to long bridges or series of bridges connected to one another by arch structures.