A coke oven of a horizontal construction of the non-recovery or heat recovery type is shown. Each disk surface comprises a plurality of tracks, each track comprising a plurality of data sectors and a plurality of embedded servo sectors, each embedded servo sector comprising a servo sync mark for synchronizing to the embedded servo sector. The channel may have a U-shaped cross-sectional area to increase the channel length and gate control. As the motor drives the connecting arm to the locked position, the locking slide moves into interfering engagement with the hub to lock the device.