The role of Bert was played by David Sharpe, who was actually a member of Republic's celebrated team of stunt men. Because of his lead on-camera role, he was doubled by teammate James Fawcett for the more dangerous stunts.
CHAPTER TITLES: 1: The Monstrous Plot; 2: The Mysterious Friend; 3: The Executioner; 4: Sabotage; 5: The Ray of death; 6: 30 Seconds to Live; 7: The Flooded Mine; 8: S.O.S.; 9: Ladder of Peril; 10: The Infernal Machine; 11: The Red Circle Speaks; 12: Flight to Doom.
Episode 1 has a running time of approximately 28 minutes. Episodes 2-12 have a running time of approximately 17 minutes each (DVD timings).
The prisoner number, 39013, is seen again in "Beavis and Butthead Do the Universe" as Beavis' prisoner number (Butthead is 39014).