Mechanical

The St. Charles Avenue Streetcar Line is the oldest surviving interurban-urban passenger rail transportation system in the United States. Originally incorporated as the New Orleans Carrollton Rail Road in 1833, service began in 1835. A variety of motive power had been used including horses, mules, overhead cable, steam engines, and ammonia engines before electrification in 1893. The 900-series cars presently in service were designed and built by the Perley A. Thomas Car Company of High Point, North Carolina, in 1923 to 1924.

The two 3,500-hp steeple compound Unaflow steam engines powering the S.S. Badger represent one of the last types of reciprocating marine steam engines. Built by the Skinner Engine Company, most Unaflow engines are single expansion. These feature tandem high- and low-pressure cylinders separated by a common head. The Badger's four Foster-Wheeler Type D marine boilers, which supply 470-psig steam to the engines, are among the last coal-fired marine boilers built. 

The SS Jeremiah O'Brien, an emergency cargo vessel of the type EC2-S-C1 better known as Liberty Ships, is one of two operative survivors of 2,751 ships, the largest fleet of single class ever built. The other is the SS John W. Brown, now in Baltimore (not operative at the time of the landmark designation). Between March 1941 and November 1945, eighteen US shipyards produced 2,751 ships. The design stressed minimum cost, rapidity of construction, and simplicity of operation. The original design and configuration have not been altered.

The innovative SS Great Britain, launched in 1843, was the first iron-hulled, screw-propelled ship to cross any ocean and led mercantile history into British domination in the late nineteenth century. Standard practice of naval and merchant ship construction derived from this ship. The compartmented hull, unprecedented 1,500-horsepower engine with chain drive, and many other seminal features were the designs of Isambard Kingdom Brunel. New design features included a balanced rudder, an electric log, a double bottom, and water-tight bulkheads.

George Washington's concern over standardization of rifles for the Continental Army led to the formation of national armory and to his selection of Springfield as its site. Completed in 1794, it was the first national armory in the United States. Like the Robbins and Lawrence Armory, the Springfield Armory was an outstanding machining center for the design and mass production, employing notable engineers such as Thomas Blanchard (1788-1864), Thomas Warner, and Cyrus Buckland.

This highly diverse facility has pioneered the development of solar energy applications worldwide. The Solar Energy and Energy Conversion Laboratory (SEECL) was unique in developing practical solar energy devices based on established principles of thermodynamics, heat transfer, and fluid mechanics long before solar energy was considered a serious energy alternative.

The Stanford Linear Accelerator Center was renamed in 2009 to the SLAC National Accelerator Laboratory.

Notable for: unique electromechanical devices and systems in the longest accelerator in the world

Siegfried Marcus (1833-1898), a remarkable engineer and manufacturer, lived most of his life and died in Vienna, leaving his most important legacy — an experimental automobile resembling today's modern car and the oldest extant automobile known worldwide. Marcus' second car, built circa 1875 (a more specific date still being investigated by historians), is believed to be the first vehicle powered by a four-cycle engine and the first to use gasoline as a fuel, featuring the first carburetor for a gasoline engine and the first magneto ignition.

The first commercial central electric-generating station in the United States to use nuclear energy was the Shippingport Atomic Power Station of the Department of Energy and the Duquesne Light Company. In a dramatic high-tech display, ground was broken in 1954 during dedication ceremonies by President Dwight D. Eisenhower, who also opened it on May 26, 1958, as part of his "Atoms for Peace" program. Shippingport is located on the Ohio River about 25 miles from Pittsburgh.

This silver mine preserves two features of bygone practice. One is the reversible waterwheel of the ore-hoist, which originally was installed in 1565 and currently dates back to 1824. The present wheel is 9 meters in diameter and reaches a depth of 700 meters.