LEGOs have been an iconic part of childhood for decades, but some sets have moved beyond the Christmas wish list and into the collector’s realm. LEGO trains, in particular, have generated a broad following for their intersection of design, creativity, and classic LEGO fun. LEGO collectors have playfully named their trains L scale, in imitation of HO and N scales of other model trains.

LEGO manufactured its first train in 1965. This model of locomotive—designed to be pushed by hand—had neither engine nor track, and it was quickly replaced in 1966 with a train that was battery-powered and ran on blue plastic rails. The 4.5V battery usually resided in a train car just behind the locomotive.

The 4.5V models were soon modified to 12V sets, which resembled Lionel model trains in that the locomotive drew power from an electrified third rail (actually two small rails), rather than from a battery. This system was replaced in 1991 by a 9V model, which featured an improved, easier to use design. Most recently, in an effort to cut costs, LEGO replaced the 9V system with a battery-operated remote control design.