Secondary Source

By 1881, he had established an engineering practice in Pittsburgh, where he built several bridges, including the Smithfield Street Bridge, a stunning example of the lenticular truss. Lindenthal also worked on a variety of railroad projects, including surveying and estimating for rail lines in Pennsylvania and the reconstruction of bridges on what is now the Erie Railroad. In 1885, officials with the Pennsylvania Railroad approached him with a project thtat, although he never got to build it, would fascinate him the rest of his life—a bridge across the Hudson River to link New York City with New Jersey.

Despite its pioneering technology in 1779, as the first structural use of cast iron, no eye witness accounts are known which describe the Iron Bridge being erected. However, recent discoveries, research and experiments have shed new light on the mystery of exactly how it was built, challenging the assumptions of recent decades. In 1997 a small watercolour sketch by Elias Martin came to light in Stockholm. Although there are a wealth of early views of the Bridge by numerous artists, this is the only one which actually shows it under construction.

The current structure is the third bridge on this site. Lewis Wernwag built the covered wooden Monongahela Bridge in 1818, the first river crossing bridge in Pittsburgh. It replaced a ferry and cost $102,000. It was destroyed in the Great Fire of 1845 and replaced the following year.
Drawing of 1818 bridge

John Roebling, creator of the Brooklyn Bridge, designed a wire rope suspension bridge which used the 6 piers and abutments from the earlier bridge (8 spans, 188 ft each). Roebling's first highway bridge operated as a toll bridge. Increasing live loads from added traffic resulted in excessive deflections and swaying, leading to its closure and replacement with current structure.

Nearly 150 years ago, William Hamilton Merritt was the man who dreamed of building the first bridge over the Niagara River. He was the same man who had planned and built the first Welland Canal making it possible for shipping to circumvent the Falls at Niagara.

In 1846, permission was received from the Governments of Upper Canada and the State of New York for the formation of two companies with the ability to construct a bridge at or near the Falls. They were the Niagara Falls Suspension Bridge Company of Canada and the International Bridge Company of New York. Both companies would build and own the bridge jointly.

In the Fall of 1847, the bridge companies commissioned Charles Ellet Jr. to construct a bridge at a site selected along the Niagara River. This site was located along the Niagara Gorge above the beginning of the Whirlpool Rapids and was the narrowest point from shoreline to shoreline. This bridge would connect the site of what would become the Village of Elgin (now Niagara Falls).

Thomas Bouch was born on 25th February 1822 in Thursby, Cumberland. He was educated at the village school, although his academic interest is said only to have been stirred by a lesson about moving water uphill. Thomas went on to spend three years as a boarder at the Academy School in Carlisle but the death of his father in 1838 led him to take up an apprenticeship with a firm of mechanical engineers based in Liverpool. Thomas quickly found the position unsuitable and returned to Thursby where he started a job as an assistant to George Larmer, a railway surveyor.

Thomas Bouch died during the public inquest into the failure of the high girders of the Tay Bridge at his country retreat in Moffat, and is buried at the Dean Cemetery in Edinburgh.

He was the engineer to the Edinburgh and Northern Railway during which time he designed the train ferry crossing between Granton and Burntisland.

Afterwards he became a consulting engineer. As an engineer he had a reputation for being able to build lines very cheaply. He went on to design many short distance lines for companies which could not afford heavy engineering.

Abraham Darby (the Grandfather of the famous bridge builder) was born in 1678 at Wrens Nest in the hamlet of Woodsetton in the Parish of Sedgley, Staffordshire, son of John & Ann Darby.

...The first of a succession of iron manufacturers who bore the same name, he was the son of a Quaker (Society of Friends) farmer residing at Wrens Nest, near Sedgley and served his apprenticeship with a maker of malt-kilns near Birmingham, Later he married and moved to Bristol around 1700, to begin business on his own.

In Bristol he was joined by three partners of the same Quaker persuasion, who provided the necessary capital to enable him to set up works at Baptist Mills, near the city. He carried on the business of malt-mill making and later added brass and iron founding

In 1885, Gustav Lindenthal, a bridge engineer who established his reputation on two notable Pittsburgh spans, was approached by officials at the Pennsylvania Railroad regarding the feasibility of a railroad crossing across the Hudson River. At that time, the Pennsylvania Railroad was at a disadvantage vis-à-vis its chief competitor, the New York Central Railroad, because it did not have a direct entrance into Manhattan.

Because of the smoke that emanated from the locomotives of the era, the railroad favored a bridge across the Hudson rather than a tunnel. After giving serious thought to a cantilever design, Lindenthal decided upon a suspension bridge because such a design would allow wider distances between piers. However, the suspension bridge would have to have a main span of about 3,000 feet, nearly twice the length of the main span of the Brooklyn Bridge completed two years earlier.

ELLET, Charles, civil engineer, was born at Penn's Manor, Bucks co., Penn., Jan. 1, 1810, son of Charles and Mary (Israel) Ellet, and grandson of Charles and Hannah (Carpenter) Ellet. His father, a farmer, was a member of a well-known Quaker family and his mother, daughter of Israel Israel of Philadelphia was one of the most remarkable women of her time, being alluded to by a Philadelphia journal as the "American Cornelia." The son was brought up on his father's farm and attended school at Bristol, Pa. From his earliest years he had shown an unusual talent and fondness for mathematics and at the age of sixteen had far outgrown the scope of the school's mathematical curriculum. After a course of study at the Ecole Polytechnique, Paris, France, he secured employment on various engineering works becoming first assistant and soon afterward chief engineer of the James river and Kanawha canal. His attention at this time was devoted chiefly to the study of methods of inland communication, more particularly suspension bridges, and in 1841-42, he constructed the wire suspension bridge across the Shuylkill river at Fairmont, the first of its kind in America.

Gustav Lindenthal had a dream. He wanted to build a bridge across the lower Hudson River, connecting Manhattan with New Jersey. I've got a far more modest dream. I want to run across the Hudson River on one of the bridges that has subsequently been built.

...Lindenthal was already a successful bridge builder when he came to New York City in 1885. He made his reputation in Pittsburgh, where he designed and supervised construction of bridges, including the Smithfield Street Bridge. Pittsburgh is a living primer of bridge construction. I don't know of a city with a denser collection of varied bridge designs. The Smithfield Street Bridge crosses the Monongahela River, connecting downtown Pittsburgh with "Sahside". This beautiful bridge is immediately recognizable with its lenticular trusses.