Walthers, Inc. Motorizing Kit DC Motor & Gearbox for Swing Bridge, Oil Pumps, Turntable & Other Kits Drop-in mount for cornerstone double-track swing bridge 933-3088 & 90' turntable kit 933-3171 Use to animate Walking beam oil pumps: HO scale 933-3170; N scale 933-3248 Can easily be adapted to other models DC motor and has 360:1 gearing to ensure smooth, slow speeds 0-12 v DC power only