The 9 V system ran from 1991 to 2006 and is still a favourite with LEGO train fans. The rails have metal tops that carry the current from a speed regulator to a motor under the locomotive, so trains could run without batteries for as long as they stayed on the track. It started with 4558 Metroliner in 1991.
1997 LEGO Sets
1997 saw LEGO’s first major sales decline, prompting experimentation and digital expansion. LEGO Island introduced the brand’s first open-world video game, setting the stage for future digital storytelling. New subthemes included Divers for underwater exploration, Fright Knights for gothic medieval fantasy, and Time Twisters as a sequel to Time Cruisers. LEGO Space added Roboforce and UFO, shifting toward alien-focused designs, while Aquazone expanded with Aquaraiders. Despite challenges, LEGO’s creativity remained strong across both physical and emerging digital platforms.