Educational toy made in plastic versions. In the mid-1950s, more explicitly engineering-themed construction toys appeared, including plastic girders, columns, and panels that could be assembled into a model curtain wall skyscraper. Later, this Girder and Panel structural system was extended to a Hydro-Dynamic setup by adding pipes, valves, tanks, nozzles, and pumps to allow construction of model plumbing, HVAC, and chemical engineering systems like a simulated distillation column. Other extensions of the system supported suburban-style housing developments (Build-A-Home), or monorail transportation systems (Skyrail). The building toy Lego was originally developed by Ole Kirk Christiansen in Billund, Denmark, in the 1930s. The name
Lego Trains Lego Trains Lego Trains is a product range and theme of the construction toy Lego, which incorporates buildable train sets. The Lego Trains theme became a sub-theme of Lego City in 2006. Products in the range have included locomotives, tracks, rolling stock, stations, signal boxes, and other track-side buildings. The theme is popular among adult fans, as well as children, and has spawned international associations and conventions. The train system is sometimes referred to as 'L-gauge' among fans, in reference to traditional model railway scales. Lego trains use a nominal gauge of 37.5mm, 5.5mm wider than O gauge, derived from