The introduction of 9V-trains in 1991 marked the end of the earlier two voltages. This third era is characterized by integral moulded dark Grey rail/tie assemblies with metal conducting rails. Later the former outstanding standard Trains theme was integrated in the LEGO World City theme line. The 9V era was finished with a special experts model of the Factory line called Hobby Trains in 2006. Lego City Train Set All Lego City Sets, lego city train set, lego city train, lego city trains, lego city train station, lego city train track, lego city sets, lego city train 2014, lego city cargo train, lego city passenger train, lego train sets, lego city trains 2014, lego train set, lego city train tracks, lego city train starter set, lego city airport, lego city passenger train 7938, lego city set, lego city cargo train 60052, lego city sets 2014, lego city toys, lego city train sets 2014, lego train city, lego city lego sets, lego city cargo train 7939, all lego city sets, lego city 2014, lego city 7938, lego city 7498, lego city train 60052, lego city starter set
LEGO 4.5V Trains were first introduced in 1966. They had blue rails and white sleepers (standard 8 x 2 plates), and the locomotives used the standard 4-wheel drive LEGO 4.5V motor unit. The wheels were flanged train wheels with rubber rims for traction, that were pushed into the motors. The batteries were carried behind the engine in a tender, or in a battery box built into the engine in the earlier sets. Lego City Train Set All Lego City Sets Since 1969, there was also a 12V train program, which used additional conductor rails mounted between the standard 4.5V rails, and 12V motors contained in the same housings as the 4.5V motors, but with additional metal contacts attached to the bottom of the housings. This first period of the 4.5V and 12V trains, sometimes called the Blue Era because of the rails colour, lasted from 1966 till 1979.