Trainmaster Command Control

Trainmaster Command Control (TMCC) is Lionel's electronic control system for O scale 3-rail model trains and toy trains. Conceptually it is similar to DCC, the open industry standard used by HO scale and other 2-rail DC trains.

It permits operation of multiple trains on the same track without complex wiring, and also gives locomotives realistic digitized sounds.

Its development was backed financially by rock and roller Neil Young, who held a stake in Lionel. Lionel has since licensed TMCC to some of its competitors, including K-Line, and aftermarket circuit boards are available to add TMCC to O scale and S scale trains that lack the capability.