As a young girl in Springdale, Rachel Carson knew the sounds of steamboats churning down the Allegheny River, carrying iron ore, oil and lumber toward Pittsburgh.
As a young woman studying at what became Chatham University, she knew the taste and smell of fine soot and ash descending from the stacks of the mills, filling every crevice.
And as the writer of "Silent Spring," she knew the high price of progress and its potential effects upon the environment and people.
Click image above for an interactive tour of Pittsburgh's bridges across the Allegheny River, with histories and details about each.
No wonder her name is attached to the last of the Three Sisters bridges linking Downtown and the North Side. The water passing beneath the Ninth Street Bridge ran through her.
Carson was a sophomore at the Pennsylvania College for Women in Shadyside when the second of three self-anchored suspension bridges opened Nov. 26, 1926. Their radical attractive design won praise from architects and engineers, and their height -- 40 feet above normal pool level now and even more then -- was applauded by people who made their living on this very industrial river.
The first of two other bridges that previously stood at this spot was a covered wooden bridge, 1839-90, extending what was then known as Hand Street. When it was being dismantled, a local violin maker asked for wood from its arches in the belief that the constant vibration from 50 years of traffic would season it like a well-used musical instrument. The Engineers Society reported that the two violins he made had a particularly sweet tone and were sold for a high price.
The Hand Street Bridge's replacement, which stood from 1890 to 1926, was a steel and wrought-iron through truss bridge designed by Gustave Kaufman and George Ferris, a North Sider better known as the inventor of the Ferris Wheel.
Thirty to 50 years was a typical lifespan for bridges up until the 1920s. During that time, workers attempted to keep the trusses and other parts protected and lubricated with a variety of what are now known as hazardous substances, including red lead and lime.
In 1888, the Engineers Society said, 4 1/2 barrels of heavy oil was poured to protect the cables of a suspension bridge at Sixth Street. When the Three Sisters Bridges were built in the 1920s, aluminum paint was the latest technology. Today, PennDOT spends more to safely repaint the Carson Bridge than the $1.44 million it cost to build it.
Until Carson's 1962 book and testimony at congressional hearings in 1963, few Americans worried about the chemicals in their food or waterways. It seems fitting that this bridge spanning a cleaner river than she ever knew was renamed for her on Earth Day, April 22, 2006.
First Published: July 21, 2013, 8:00 a.m.
