Working titles for this story included
Peepshow. This story was recorded as part of the production block for the previous season but deliberately held over for Season 10. This was to enable Barry Letts to direct, since his role as producer would have made it difficult to do so at the start of a production block (as he had found out with
Terror of the Autons). The titles for
Carnival of Monsters were prepared, alongside the next serial,
Frontier in Space, with a new arrangement of the theme music performed by Paddy Kingsland on a synthesizer. Known as the "Delaware" arrangement (the
BBC Radiophonic Workshop was based on Delaware Road), it proved unpopular with BBC executives, so the original
Delia Derbyshire theme was restored, and only appears on an uncorrected version of episode two that was shipped to Australia in error. This edit, which also featured a few extra scenes, was used in the 1995
VHS release. (The opening and closing title sequence versions of the theme have been included as an extra on the
DVD release of the story. The original 2m 30sec theatrical release of this music was
wiped many years ago.) The ship used was the
RFA Robert Dundas which had been decommissioned and was scrapped immediately after filming. As the ship was actually in transit on its final voyage down the
River Medway in Kent, all external shots had to be filmed at a low angle or the banks of the estuary would have been visible.
Cast notes Ian Marter later played the
Fourth Doctor companion
Harry Sullivan. He had previously auditioned for the role of Captain Mike Yates. Both
Cheryl Hall and Jenny McCracken were earlier considered for the part of companion Jo Grant. According to the DVD commentary for the 'Special Edition' of the story, they were on the final shortlist of six actresses seen for the role. Producer Barry Letts promised both actresses he'd use them in the future after offering the part of Grant to Katy Manning. ==Broadcast and reception==