Engineers designing bridges for US railroads in the late nineteenth century had a lot of work, as roughly 100,000 miles of new track were built between 1880 and 1900. If you include work performed by US engineers and builders elsewhere, the number is considerably higher. The 1889 Poughkeepsie Railroad Bridge, above, is an interesting case: it’s a technically-proficient and attractive Warren cantilever truss, but it was located on a line with low traffic and was drastically underused for most of its life before being abandoned and then turned into a pedestrian walkway.
The high trestle of the Colorado Midland Railway near Buena Vista, Colorado, (the 1887 Hop Gulch Trestle, I believe) is conceptually as simple as it gets – a series of simply-supported plate girders – but it’s location must have made it difficult to build:
The 1880 bridge built for the Chicago, St. Paul, Minneapolis & Omaha Railway in Eau Claire, Wisconsin, is as nice a lattice truss as you’ll see, sitting on very old-fashioned stone piers:
I could keep going indefinitely, but will finish with the 1901 Chicago & North Western Railway bridge over the Des Moines River in Iowa, informally known as the Kate Shelley High Bridge. Here it is shortly after completion:
And in 1995, as part of its HAER survey:
Baltimore trusses are, frankly, gawky in appearance, but the subdivided panels allow for very slender elements, as can be seen here.
There are a lot of ways to create a span, and none is the one right way.
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