In 1972 LEGO released the 4.5V and 12V train sets as part of the Blue Era which was named because of the rail color. These train sets 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.
1981 LEGO Sets
In 1981, LEGO continued to expand its thematic range to cater to the diverse interests of its global audience. This year saw the introduction of the LEGO Fabuland theme, designed for younger builders transitioning from DUPLO to regular-sized LEGO bricks. The Fabuland sets stood out due to their unique anthropomorphic animal characters and simple builds, offering stories that blended town and country life. Alongside this, the established Town and Space themes received new additions, bolstering LEGO's offering for fans of those lines.