Civil Engineering Reference
In-Depth Information
FIGURE 1.13
Fraser River Bridge built in 1884, British Columbia, Canada. (From Canadian
Pacific Archives NS.11416, photograph by J.A. Brock. With permission.)
across the Niagara Gorge parallel to Roebling's railway suspension bridge. Shortly
afterward, in 1884, the Canadian Pacific Railway crossed the Fraser River in British
Columbia with the first balanced cantilever steel deck truss (Figure 1.13). Cantilever
bridges became customary for long-span railway bridge construction as they provided
the rigidity required to resist dynamic train loads, may be made statically determinate,
andrequirenomainspan(composedofcantileverarmsandsuspendedspan)falsework
to erect.
Table 1.5
summarizes some notable cantilever railway bridges constructed
after 1876.
Theodore Cooper promoted the exclusive use of steel for railway bridge design and
construction in his 1880 paper to the American Society of Civil Engineers (ASCE)
titled “The Use of Steel for Railway Bridges.” Following this almost all railway
bridges, and by 1895 all other bridges, in the United States were constructed of steel.
Structural steel shape production was well developed for the bridge construction
market by 1890.
∗
The British government lifted its ban on the use of steel in railway bridge construc-
tion in 1877. More than a decade later Benjamin Baker reviewed precedent cantilever
bridges in North America (in particular, those on the Canadian Pacific Railway) and
∗
By 1895, structural shapes were no longer made with iron, and steel was used exclusively.
