The sound effect heard when the Time Tunnel is powering up was used in many Twentieth Century-Fox productions. Among others, the effect was used for both the Jupiter II in Lost in Space (1965) and the Icarus in Planet of the Apes (1968).
When Doug states "The Dutch liner's picked up our CQD", this translates to "All stations: distress".
The entrance to the elevator to the complex is the same doorway used for alien space ships on Lost in Space including that of The Keeper.
This episode takes place aboard the RMS Titanic on April 14, 1912 and in Arizona in 1968.
Dennis Hopper: in the background after Tony appears on the deck of the Titanic; and just after Doug helps the little boy into a lifeboat, Hopper can be seen behind Doug disguised as a woman. At least three scenes were shot with Hopper, but appear to have been cut before it aired.