What is an Arch Truss?

An arch truss is a truss that includes the shape of an arch. These kinds of trusses are common in many different types of buildings. Traditional trusses are made with wood, but some truss types are also made of metal.

In residential work, trusses are used to support a roof. Residential construction rarely uses arch trusses, since the standard roof design is triangular. However, for dome type buildings, an arch truss may be part of what an engineer uses to implement the design.

The arch truss is often used in building bridges, where the truss can be made of wood (typically in older bridge designs) or metal. One main type of bridge design is an arch bridge, where the load on the bridge is deposited toward supports on each end. Another common bridge style is a truss type bridge, where triangular trusses bear the load on a bridge structure. An ‘arch truss bridge’ is a combination of these two, where a number of triangular trusses can have an overall arch shape.

An arch structure can be helpful in many different kinds of construction design. Typically, a bridge or other structure benefits from having a series of trusses arranged in an arch shape. The series of triangular trusses forms a single arch. This arch is uniquely engineered to support a structure.

Arch trusses come in a variety of shapes and constructions. One of these is the bowstring arch truss, where the trusses create a long, thin arch. The bowstring arch truss can cause specific challenges for those involved in fire or structural safety work.

To help first responders and others, some public works officials are looking at implementing a labeling system for certain kinds of roof trusses. Others are looking at how truss design impacts safety for bridges. Engineers constantly evaluate truss styles to see how they can contribute to structural safety for a specific project. These professionals may use CAD (Computer Aided Drafting) tools and other new technology to provide the best truss design for a residential, commercial or public works project.

For more on the difference between an arch truss bridge and other types, Internet users can find many examples of this kind of architecture online. Blueprints, schematics, or actual photographs can help illustrate how the arch shape contributes to stability in these bridge projects. Similar styles may also be visible in exterior walkways and other installations.