Howe Truss Bridge Design
Howe truss is a type of bridge design that was introduced by an American
architect William Howe.
It utilizes similar design such as Pratt truss, but
with a strong difference. Here the diagonal structural beams slope toward
the bridge center, while Pratt truss utilizes diagonal beams that slope
outward from the center of the bridge. This approach makes diagonal members
of Howe truss bridge in compression, while vertical web members are in
William Howe was born in Spencer, Massachusetts, on May 12, 1803. After
working as an apprentice in his father’s sawmill, he enrolled and graduated
as an engineer at Leicester Academy in Leicester, Massachusetts. After
several years of buildings homes and churches, in 1840 he managed to
finally focus on his dream projects – building bridges. That same year he
designed his first railroad bridge over the Connecticut River utilizing
never before seen truss design that he devised. This Howe Design was
purchased by his employer Amasa Stone for exclusive use in New England,
where he created hundreds of bridges with this design approach.
Howe made numerous smaller improvements to his design and patented them
under new Howe Truss design in 1846.
William Howe died suffering wounds from carriage accident on September 19,
In some form, two of William Howe’s bridges remain today:
- A wood covered bridge on the east branch of the Ausable River in Jay,
Essex County, New York, USA. The original bridge was destroyed in a severe
flood in 1856, but it was rebuilt next year using Howe truss design. The
bridge got damaged once again in 1953. Today it is used only by pedestrians
Sandy Creek Covered Bridge
– This bridge spanning 22.7 meters is of the three surviving original Howe
Truss bridges that are still in use in the state of Missouri. It was
constructed in 1872, partially destroyed by high waters in 1886, and
restored quickly after. Sandy Creek Covered Bridge was added to the
National Register of Historic Places in 1970.