What Are CFCs? CFCs are short for the compound, chlorofluorocarbon, which contain carbon, chlorine, and fluorine. Chlorofluorocarbons are more commonly referred to as CFCs or, when used for refrigeration, CFCs are also known as freon. Developed in the 1930s as a safe alternative to ammonia, usage of CFCs grew rapidly because of its usefulness and convenience throughout most of the 20th century.
Great Northern Railway 1893-1925 The first route over the pass was a series of switchbacks, with grades of up to 4 % on the West side and 3.5% on East side, was completed on January 6, 1893 (see photos below). To traverse a switchback the train has to travel to the end of the dead end spur, then the switch is thrown and engine reverses
Norfolk Southern Railway (1942â82) The Norfolk Southern Railway (reporting mark NS) was the final name of a railroad that ran from Norfolk, Virginia, southwest and west to Charlotte, North Carolina. It was acquired by the Southern Railway in 1974, which merged with the Norfolk and Western Railway in 1982 to form the current Norfolk Southern Railway. In May 1920, the NS leased the Durham and South Carolina Railroad, which became its Durham branch. This would be the largest the NS would become at 942 route miles.