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
It was also known as the North Western. The railroad operated more than 5,000 miles (8,000 km) of track as of the turn of the 20th century, and over 12,000 miles (19,000 km) of track in seven states before retrenchment in the late 1970s.n July 1, 1968 the 1,500 mi (2,400 km) Chicago Great Western Railway was merged into the North Western. This railroad went from Chicago to Oelwein, Iowa. From there lines went to the Twin Cities, Omaha, Nebraska, and Kansas City, Missouri.