PA

"For 273 years, the little stone bridge that carries Frankford Ave. across Pennypack Creek has been doing its humble job with a minimum of attention..." 
 - Gerald McKelvey, The Philadelphia Inquirer, September 16, 1970

At a time when steam power was finding its first uses in America, Philadelphia opened two steam pumping stations, January 1801, to lift water from the Schuylkill River and distribute it through the city's wooden pipes and mains. By 1811 a new water power works was begun on the river near Morris Hill, and the Fairmount Water Works opened September 7, 1815. These water works represented the first large-scale application of steam pumping to water service in the country.

Operated by the Philadelphia Electric Company (PECO), now known as Exelon Corp., Eddystone Station Unit #1 is a 325 MW pulverized-coal-fired plant that pushed the technology of steam-electric generating plants. When built in 1960, engineers sought to make a more efficient plant using higher temperatures and pressures and larger machines. Previous experience at Philo 6 (Zanesville, Ohio, 1957) had demonstrated supercritical steam plants would work, so engineers pushed beyond that frontier to even larger machines and efficiencies.

Designed by Sam Diescher, son-in-law of the Monongahela's designer John Endres, the Duquesne Incline opened May 20, 1877, as the second of seventeen built and operated in the Pittsburgh area. It has operated with only minor interruptions for the last one hundred years. A preservation group from Duquesne Heights and Mount Washington interceded in 1962 to refurbish this incline to working order. Like the Monongahela, the Duquesne was steam powered and then converted to electric and updated with modern safety devices.

Not only was Dunlap's Creek Bridge the first cast-iron bridge in America, it was the first metal bridge anywhere to use what its builder, Capt. Richard Delafield, U.S. Army Corps of Engineers, described as "standardized, interchangeable, manufactured parts." The bridge was built as part of the federal government's effort to make repairs on the National Road  before handing authority over to the states. Dunlap's Creek at Brownsville was an especially troublesome crossing, having destroyed three previous bridges since 1801.

The drilling of this oil well marks the modern phase of the petroleum industry. A series of revolutionary technological changes, unforeseen even by the most prophetic, followed. Drake demonstrated practical oil recovery by applying salt-well drilling techniques, including the use of the derrick, and invented the modern method of driving iron pipe.

Before the Davis Island Lock & Dam were built, the flow of the Ohio River slowed to little more than a trickle during dry periods. For several months each year, the unreliable flow stranded Pittsburgh's steamboats, towboats, and barges.    

The Davis Island Lock & Chanoine Dam experimental project was the first lock and dam ever constructed on the Ohio River. Its achievements also included the first rolling lock gates, the largest movable dam built in the 19th century, and the widest chamber in world history.    

Early internal combustion engines produced only a few horsepower and were unable to replace steam engines in most applications until about 1890. By then, they were powerful enough for most portable or remote locations and many small manufactures. By 1900, they were replacing reciprocating steam engines for electric generation, and by 1915, they were being considered for all but the largest installations where steam turbines have dominated to date.

The total length of the Columbia-Wrightsville Bridge is 7,374 feet. Its construction required 100,000 cubic yards of concrete and 8 million pounds of steel reinforcing rods.