Railcars began as spartan constructions of train-specific wheels and couplers attached to car bases made from universal plates and bricks, but these were quickly replaced by black single-piece bases in two lengths that included captive wheels and couplings. The Gray Era (1980-91) In 1980 the trains theme received a major overhaul (although in some markets, the second generation system was not introduced until 1981). The builds were adapted to the minifigure, which had been introduced in 1978, with buildings that were intended to integrate with the new Town theme. The colour of the tracks was changed from blue to grey, and the 12-volt transformer changed to support utility functions in a more streamlined style with control switches that docked alongside the transformer, following the design style of increasingly streamlined model train controls of the time. The utility functions now included remotely controlled points, signals, wagon de-couplers and level crossings. The models gained a much more realistic appearance, including some with much longer carriage/wagon bodies and swivel bogies, and there were special windows which simulated having a pull-down glass section. Stickers were included allowing the owner to bedeck their trains with symbols of several European railway companies, such as DB, ÖBB, NS, SBB, DSB, NSB and British Rail. The railcar bases were now again assembled from train-specific wheels and coupler and a greatly increased number of universal pieces. As with the previous generation, the electrical parts such as the train motor (7865) and the mains transformer unit (7864) were manufactured by Bühler on behalf of Lego. The transformer unit was also compatible with Technic motors. Battery-operated trains were still available. The motor was kept unchanged. Upgrading a battery-operated train to a 12-volt electric train required changes to the train to fit the smaller, redesigned 12-volt motor underneath. The fixed wheels of the new 12-volt motor were black, finalizing the color scheme that had developed in the blue-track era, where 12-volt locomotives started to be distinguished by black wheels. The 1980 train catalog and ideas book (7777) enticed Lego fans with nighttime dioramas featuring lampposts and lights inside the trains. Even though light bricks of the same size were available in both 12-volt and 4.5-volt guise, the train headlight/taillight (using unique prisms and holder bricks) and lamppost sets were normally only available with the expensive 12-volt light bricks included. Making these theoretically universal features available only as 12-volt items served to further