 BBC Visual Effects destroyed their only model of Red Dwarf for a  sequence in the fifth series episode "Demons and Angels", where  Krytens triplicator sets off a chain reaction that destroys the  ship. The production team made sure that all model sequences  required for the current series were completed beforehand. The ship  doesnt appear in the sixth series (the running plot being that of  Red Dwarf having been stolen) and only appears in the seventh series  as archive footage from earlier episodes. It wasnt until the eighth  series that a computer