For the Thomas series Lion Chief I just run them all off a Lionel Transformer and turn the power down so the kids cannot run them off the rails.
The sounds work fine as do the trains.
Noted a Lionchief Polar Express set at another layout the kids had the train running at warp speed most of the day.
Keeping the power lower saves the engines from wearing out or flying off the track. Pity Lionel did not just gear them lower so they have a bit more pull but less warp speed, when the remotes are handed out to the kids.
