engineering

Smithfield Street Bridge

Smithfield Street Bridge is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Smithfield Street Bridge rather than just read about it. In short: The Smithfield Street Bridge is a lenticular truss bridge crossing the Monongahela River in Pittsburgh, Pennsylvania, United States. The bridge was designed by Gustav Lindenthal, the engineer who later designed the Hell Gate Bridge in New York City.

Key takeaways

Smithfield Street Bridge belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Smithfield Street Bridge to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Smithfield Street Bridge from memory before moving on to harder problems.

Reference excerpt

The Smithfield Street Bridge is a lenticular truss bridge crossing the Monongahela River in Pittsburgh, Pennsylvania, United States. The bridge was designed by Gustav Lindenthal, the engineer who later designed the Hell Gate Bridge in New York City. The Smithfield Street Bridge was built between 1881 and 1883, opening for traffic on March 19, 1883. It was widened in 1889 and widened again in 1911. The bridge has been designated a National Historic Civil Engineering Landmark, a National Historic Landmark, and has a Historic Landmark Plaque from the Pittsburgh History and Landmarks Foundation.

History The present bridge is the third bridge at the site. It remains the second oldest steel bridge in the United States. In 1818, a wooden bridge was built across the Monongahela by Louis Wernwag at the cost of $102,000. This bridge was destroyed in Pittsburgh's Great Fire of 1845. The second bridge on the site was a wire rope suspension bridge built by John A. Roebling. Increases in bridge traffic and river traffic eventually made the lightly built bridge with eight short spans inadequate. The Lindenthal bridge was built in its place, using the Roebling bridge's stone masonry piers. The Smithfield Street Bridge is the penultimate of the many bridges that span the Monongahela before the river joins with the Allegheny River to form the Ohio River at Downtown Pittsburgh. Only the Fort Pitt Bridge is farther downstream. The bridge also served the Pittsburgh Railways streetcar system with lines coming from the Mt. Washington Transit Tunnel and from Carson Street, crossing the bridge and continuing into downtown along Grant Street and Smithfield Street, returning to the bridge via Wood Street or Grant Street. The tracks occupied the eastern half of the bridge. The streetcar line was abandoned in July 1985, when the streetcars were diverted to the Panhandle Bridge and the new light rail subway, on July 7. The last day of streetcar service on downtown Pittsburgh streets and over the Smithfield Street Bridge was July 6, 1985, although the final crossing of the bridge by a streetcar did not take place until 1:40 a.m. on July 7. The former streetcar right-of-way was converted into a paved roadway for northbound traffic. The bridge was listed on the National Register of Historic Places on March 21, 1974. Two years later, on May 11, 1976, it was designated a National Historic Landmark. The bridge's short clearance from the river and its deteriorated condition convinced PennDOT officials to demolish and replace it with a modern bridge. Officials considered lobbying by the Pittsburgh History and Landmarks Foundation on preserving the bridge. In 1994–1995 the bridge was rehabilitated with a new deck, a colorful paint scheme, and architectural lighting. The abandoned rail lines became an extra traffic lane, and a light-controlled bus lane was added during peak traffic hours. The bridge also has the distinction of being the bridge most heavily walked by pedestrians, mostly commuters who park at Station Square. The bridge connects Smithfield Street in Downtown Pittsburgh with Station Square.

Gallery

Popular culture The bridge is featured in the 1993 Bruce Willis film Striking Distance, the opening scene of the 1983 film Flashdance and the 2010 rap video Black and Yellow.

Illustrations

Worked examples

Example 1 — a first encounter with Smithfield Street Bridge

Start with the simplest possible case. Write down what Smithfield Street Bridge claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Smithfield Street Bridge before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Smithfield Street Bridge ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Smithfield Street Bridge

In research: Smithfield Street Bridge appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Smithfield Street Bridge in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Smithfield Street Bridge is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bridges completed in 1883, Bridges in Pittsburgh, Bridges over the Monongahela River, so understanding it makes those chapters shorter.
In everyday life: Look for Smithfield Street Bridge outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Smithfield Street Bridge in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Smithfield Street Bridge means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Smithfield Street Bridge out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Smithfield Street Bridge in simple terms?

Why does Smithfield Street Bridge matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Smithfield Street Bridge?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Smithfield Street Bridge.