SS Matilda Briggs

The SS Matilda Briggs was the P&O ship on which Bernice Summerfield, the Seventh Doctor, John Watson and Sherlock Holmes once sailed from Tilbury to Bombay and back. (PROSE: All-Consuming Fire)

Behind the scenes
Andy Lane's use of Matilda Briggs is an Easter egg for Sherlock Holmes fans. Arthur Conan Doyle had Holmes mention the Briggs in The Adventure of the Sussex Vampire. There, Holmes says the Briggs had to do with the case of the, "a story for which the world is not yet prepared". The inference Lane seems to want his audience to draw by stressing the name of this ship, and then having the Doctor and his friends battle an alien rat, is that All-Consuming Fire is indeed this missing story from Sussex Vampire.

And it almost fits, except for the fact that the Matilda Briggs gag in Sussex Vampire depends on Watson not understanding that Briggs was a ship, not a woman. Since he travelled onboard for weeks in All-Consuming Fire, he'd hardly need Holmes to say, "Matilda Briggs was not the name of a woman, Watson."