November 22, 1975, and Dr Who celebrated its 12th birthday, still going strong with Tom Baker at the helm. But if the show was in fine fettle for its age, the Tardis was not. Said producer Phillip Hinchcliffe: "The Tardis is supposed to disguise itself as some everyday object. This one disguised itself as a police box - and stuck like that. But blue police boxes are being got rid of. So I'm worried that some younger viewers will not know what it is supposed to be...
"Also, Tardis is getting very frail now. Whenever we take it to a new location, it falls to pieces. So we are having to decide whether to make a new one the same shape, or maybe find some reason for changing it."
Design a new Tardis! Could you invent a new time-travel machine to take over from the poor, battered old Tardis? asked the Sun in its Dr Who competition for 14s and under. Top prize was a "date with Dr Who at the BBC television studios in London" and a Dr Who board game from Denys Fisher Toys. 20 runners up were awarded board games.
The Dr Who production team, of course, decided to stick with tradition and the Tardis retained its familiar police box guise.
Quite right too!