9v Battery Powered Trolley

In 2006, LEGO will release 9V battery powered trains.  Here is a 9v battery powered trolley I bult around 1998.  It can run on 9v metal track or 4.5v gray track.  The trolley automatically reverses when it reaches a stop block (a 2x2 tile, on top of a 2x2 plate, attached to the middle of the track).   I technic axle hangs down and is connected, through a connecting link to the arm on a 9v polarity reversing switch.  When the trolley hits the stop bloc, the polarity switch is turned, polarity reversed to the motor and the trolley reverses direction.  This trolley uses the larger, 9v motor for the wheels.

At the time this was built, green bricks were considered very rare.