Abstract: A series of storage stacks, such as bookcases, are mounted on a track with controlled power means for moving them to provide a single aisle between any two stacks. The remaining stacks are in contact with each other, thereby conserving space and lighting means. The movement of the stacks, the lighting above the open aisle, and the safety features are all automatically controlled. All controls are mounted above the floor level.

Abstract: A series of storage units, such as bookcases, are mounted on a track with controlled power means for moving them to provide a single aisle between any two units. The other units are adjoining each other for conserving space and lighting means. The control means for each unit is mounted within the unit itself instead of coupled to an external master control. Any unit may be removed from the series without affecting the other units and a control circuit can be replaced without affecting the adjustment and operation of the other control circuits. The movement of the units is controlled so that the units move in sequential manner, spreading the motor current surges over a short time interval.