Large Scale Central

How Much "Juice" for 1/2 of a Bmann 45 Tonner?

OK Guys

I have a “project” in the works. I am utilizing 1 of my Bmann 45 Tonners Drivers to motivate ________.

I want it to be slow, and gentle on the tracks-no races to win.

How much power (battery) would you recommend? May only pull 1 small car (henrietta), and that may house the battery/RCS?!

Hint-Steam Engine, but not a “proper steam engine”, Wood Box. no whistle only a bell, Thomas’ ever faithful friend…

Built to 1/20.3

thanks
cale