Vintage LEGO 4.5V Train 7722 Battery Train Set from 1985 Steam Cargo - YouTube
LEGO MOC 7722 NG - Powered Up tender & freewheel locomotive mod by CoolHand505 | Rebrickable - Build with LEGO
Lego set number 7722 Battery Train Set, Excellent
Train Battery Box Car with Red Switch and Black Wheels with 'DB 7722' and Weight Table Pattern on Both Sides (Stickers) - Set 7722 (Undetermined Type) : Part x488c02pb01 | BrickLink
LEGO 7722 Steam Cargo Train, Battery Set Parts Inventory and Instructions - LEGO Reference Guide