Spanning throughout the Years and Across the Mon: The Smithfield Street Bridge

By Luke Carothers

Steel City, the City of Bridges, Three River City—Pittsburgh has no shortage of nicknames, self-ascribed or otherwise.  The city of Pittsburgh, PA is located at the meeting point of three rivers.  Founded as Fort Pitt in 1758, the city and the people who live in it have developed a strong identity and rich culture.  This identity and culture is writ large on the Steel City to this day.  Much of the tradition that still colors the city today is a legacy of the city’s built environment.  Straddling the confluence of three rivers, nestled amidst steep hills, Pittsburgh developed in patterns unlike many other American cities.  And, of course, this development was fueled by an unparalleled history of industry and labor, which made Pittsburgh a place of rapid growth for nearly a century and a half from around the start of the 19th century and into the 1950s.

Pittsburgh’s industrial history can be traced back to America’s conflict with Britain known as the War of 1812.  Coming into its own as a young nation, the US faced significant challenges from the experienced British military as well as another logistical challenge—their enemy was then the manufacturing capital of the world.  Faced with developing their own industrial centers and unable to effectively use sea trading routes, the United States turned towards its interior where Pittsburgh, with its rivers serving as the super highways of the day, provided the perfect location.  Factories quickly began to rise up in the city along the rivers to produce iron, tin, brass, and glass.

This early period of growth during and after the War of 1812 led to one of the first major engineering projects: the Smithfield Street Bridge.  Today, the Smithfield Street Bridge cuts a remarkable image across the background of Pittsburgh’s downtown skyline.  Clad in blue and beige, the 1,184-foot over-and-under lenticular truss bridge spans the Monongahela River and, at night, adds color to the city’s polychromatic skyline.  However, while the Smithfield Street Bridge was one of the first in America to be constructed with structural steel, two other bridges existed at that spot in the city’s history.

To support their rapidly expanding industrial base as well as a growing population following this initial period of growth, Pittsburgh began to expand its infrastructure.  There was a growing need to improve the ability to ship goods and resources as well as find new places for this growing population to live.  Stoking the fires of competition, the first segment of the National Road was completed from Baltimore to Wheeling, giving the nearby Wheeling an early advantage over the growing city of Pittsburgh.  Pittsburgh responded with a massive infrastructure boom that transformed the city in the coming decades.  This period of massive infrastructure expansion began in 1818 with the construction of the region’s first river bridge at the current site of the Smithfield Street Bridge.

Pittsburgh turned to one of its earliest engineers, Lewis Wernwag, to create the first transportation over the Monongahela River.  Like many of Pittsburgh’s citizens throughout the years, Wernwag was an immigrant, coming from Germany to the United States a few decades prior.  His design for the bridge was a wooden span that cost around $100,000.  While simple in its design and material, Wernwag’s wooden bridge spanned the Monongahela River for nearly three decades before being destroyed by a city-wide fire in 1845, and the decision was made to immediately replace the wooden structure with a more modern design.

Again turning to a German-born engineer, the notable John Augustus Roebling was commissioned to design the replacement structure.  Roebling’s design was a wire suspension bridge, which stood for around four decades before being made obsolete by the late 19th century due to increases in bridge and river traffic.  For the third time, the city turned to the engineering expertise of an immigrant, this time employing the expertise of the renowned Austrian-born engineer Gustav Lindenthal who designed the remarkable structure that now bears the name of the Smithfield Street Bridge.  Still proudly spanning the Mon, as the river is known locally, Lindenthal’s structure is part of a vast history that is woven throughout Pittsburgh’s built environment.