An apparatus is provided for operating a segmented sliding overhead door. The door is of the type for sliding in a pair of side tracks mounted at either side of the door between a dosed vertical position and an open horizontal position. A driver is mounted at the side-to-side center of the door and extends away from an interior side of the door. The driver includes a screw drive shaft adapted to be mounted horizontally above the door. A motor is engaged with the drive shaft and provides reversible rotational drive force to the drive shaft. A drive shaft coupling unit engages the drive shaft for moving along the drive shaft in response to rotation of the drive shaft. A track assembly engages and supports the rotating drive shaft and guides the coupling unit in linear travel along the drive shaft. A door connecting rod assembly serves to rigidly jam the door against the floor when the door is in the fully closed position, and connects the carrier unit to the door for moving the door along the side tracks. Preferably, a safety release is included for releasing the connecting rod assembly from the door so that the door may be manually operated. The apparatus is particularly shock resistant.