Bay 47 was an area aboard the JMC mining spaceship Red Dwarf used as quarantine. The entire bay, including the landing deck, was mostly cream-coloured and sterile-looking. Bay 47 had it's own shuttle bay, and over a hundred and fifty isolation bunk rooms of various sizes. The isolation suites were all connected by an external medical area with viewing windows onto the suites.
Bay 47 was also the parking space occupied by Voter Colonel Sebastian Doyles Limousine in the crews Dispair Squid induced hallucination in the episode Back to Reality.
Space Corps Directives (SCDs) decreed that any potentially infected human crew, and any animals or GELFs, must be kept here for three months, before joining the rest of the population aboard Red Dwarf. After purchasing a pet cat named Frankenstein on planetary shore-leave, Dave Lister did not put Frankenstein through quarantine, instead illegally smuggling the pet aboard. Holly sensed the presence of the cat, and Captain Hollister was altered when Lister sent photographs to the ship's lab to be developed of himself with the cat. Lister refused to give up the Cat, and so was punished with 18 months of stasis. (Pilot episode)
Three million years after the radiation disaster, Rimmer had an argument with the others about how they don't respect his authority as most senior ranking crewmember when they ignoring his command to launch scouter, and believing that Kryten was taking over with his Space Corps Directives. After being furnished with a SCD book by Holly, Rimmer decided that he would use it to fullness in his utmost pettiness. After, the others were returning from Hildegard Lanstrom's planet in Starbug, and Rimmer - who was aboard Red Dwarf - took over remote control of Starbug, arguing that they could have been carrying the "hologram equivalent of foaming dog fever."
Rimmer forced the three others into Quarantine Room 152, a room of Bay 47 resembling typical sleeping quarters, but with only one bed. Rimmer justified this by saying that Lister was the only JMC-registered crewmember, and so only one bed would be provided, as per the SCDs. Rimmer subsequently did everything he could to make the three months pass as unpleasantly as possible, such as providing them with little entertainment except a perpetually-looped tape of Reggie Dixon's Tango Treats. He also forced them to eat sprouts for every meal, since sprouts made Lister throw up. The three began to get on each others nerves in very little time, ending with Lister with black eyes, Cat with a broken nose, and Kryten having to remove his head from the Waste Disposal.
It became clear that Rimmer was under the influence of the Holo Virus, contracted from Lanstrom over radio waves, when Rimmer appeared in the viewing area dressed in a gingham dress and army boots, and talking through a fearsome penguin hand puppet and requesting they worship The King of the Potato People. Rimmer soon threatened to cut off their oxygen for being "bread baskets", and tried to use his hex vision on them. With the help of Lanstrom's luck virus which they had found earlier, Lister was able to punch in the correct door locks to escape Bay 47.
They eventually disabled Rimmer by finding a remote link to the Hologram Simulation Suite. When Rimmer came to, his core program restored, he was bemused to found himself laid on a gurney and sealed in the same room he had sealed them in, Quarantine Room 152 in Bay 47. The others then appeared in the Observation room dressed as Rimmer had been when he was insane - wearing gingham dresses - and cackling and acting maniacally, for a little payback against their former captor. ("Quarantine", Series V)