Mechanical

The refrigeration units placed on trucks in 1938 by Thermo King Corp. revolutionized the transportation of perishable foods. Today they are a common sight on streets everywhere. Consumer demand for meat, poultry, produce and dairy products increased at an astounding rate. These installations and subsequent ones on refrigerated vehicles, ships, and railroads have had worldwide impact on the preservation of food and other perishables during distribution.

The articulated wheel-base steam locomotive represents the final phase of steam locomotive development in size and power. The cab-in-front feature was widely used by the Southern Pacific Railroad beginning in 1909 to alleviate smoke and heat problems for locomotive personnel en route through tunnels and snow sheds. This locomotive, built by the Baldwin Locomotive Works, operated between 1944 and 1956 before being displaced by a diesel-electric locomotive.

The 4,620-horsepower GG1 was primarily a passenger locomotive, routinely operating at over 100 miles per hour, but was used in freight service as well. Conceived by the Pennsylvania Railroad and built by the Baldwin Locomotive Works and General Electric Company, No. 4800 logged nearly 5 million miles in its forty-five-year life. It was the prototype for a 139-unit fleet built during a decade to serve on the PRR's electrified lines, and the only one with a riveted body shell; the remainder were welded.

Developed for use in both the plains and mountains, this coal-fired passenger locomotive was among the most advanced in design, construction, and performance of any 4-8-4. Designed by Norfolk & Western engineers and built in the Norfolk & Western Roanoke shops, the 611 was specially balanced to minimize rail damage at high speeds. No. 611, eleventh of fourteen constructed and the last survivor, was retired from service and donated to the Roanoke Transportation Museum in 1959.

The Wildcat's innovative "Sto-Wing" mechanism developed on the XF4F-4 prototype by Leroy (Roy) Grumman (1895-1982), a founder of Grumman Aircraft Engineering Corporation, was crucial to the U. S. Navy's success during World War II.

The idea of a folding wing was not new: as early as 1920, F.M. Osborne patented a high-wing monoplane with folding wings, but never produced this design. A 1928 plane with folding wings designed by W. Leonard Bonney crashed on its first flight.

America's first practical helicopter, it pioneered the single main rotor concept that became the predominant helicopter configuration throughout the world. The principles that were developed and demonstrated by the VS-300 had direct application in the design of the early mass-production helicopter, marking the beginning of the world's rotorcraft industry.

The initial flight of the VS-300 was piloted by its designer, Igor I. Sikorsky (1889-1972), on September 14, 1939, in Stratford, Connecticut.

The Connecticut Light & Power Company pioneered the use of pumped storage in the United States at this hydroelectric station. First operated in 1929, the Rocky River Plant had two reversible pumps that somewhat resemble large hydroelectric turbines. This permitted significant improvements in the system efficiency of the company's network of hydroelectric and thermal-electric power generating plants. Water is pumped uphill through a penstock and stored in Lake Candlewood.

The largest mine hoist in the world, it serves the two incline skipways of Shaft No. 2, almost 9,300 feet long. The overhead winding drum has a diameter of 30 feet, of which the cylindrical center section is 10 feet long. The two 10-foot long end sections taper down to a 15-foot diameter. Wire hoisting ropes (almost 27 tons) could be wound onto a small end of the cylindrical drum as the other rope unwound from the cylindrical section.

Only since 1912 have glass jars and bottles been in cheap and plentiful supply for pharmaceuticals, household products, food and beverages, and an endless variety of uses. The bottle-making machine introduced the safety, standardization, quality, and convenience of glass containers. Not only did they revolutionize the industry, the Owens machines ended child labor in glass-container plants. In 1913, the National Child Labor Committee of New York City said the rapid introduction of the automatic machine did more to eliminate child labor than they had been able to do through legislation.

This low-head operating plant is representative of nineteenth-century hydropower-plant practice using many small turbines in contrast to twentieth-century use of few large turbines and generators. Its 40,000 horsepower capacity made it the largest in the country using turbines of American design (McCormick-Francis). The contemporary and larger Niagara installation used turbines of French design (Fourneyron). The entrepreneur of this plant was Francis Clergue, a lawyer, who employed as his chief engineer Hans A.E. von Schon, a German immigrant who had served with the U.S.