These are the first LEGO trains, sold from 1966 to 1971 and run on 4.5 volts. The power came from a battery box holding three 1.5 volt batteries, carried in a tender or wagon behind the engine, and the motor of 1966 was the first LEGO motor of any kind. The track was blue rails clipped onto sleepers, which is where the name Blue Era comes from.
1967 LEGO Sets
In 1967, LEGO standardized its model scale, moving from the 1:87 Town Plan format to the larger 2×2 wheel scale used in Train and Model Maker sets. This unification set the stage for the modern LEGO System and the eventual minifigure scale of the late 1970s. New innovations included black rubber tires, the first hinge elements, and LEGO’s earliest promotional tie-ins—six exclusive sets released through Kraft Velveeta. The phasing out of Town Plan and 1:87 vehicles marked the end of LEGO’s early era and the beginning of a consistent global design standard.