Third Technician David Lister (the lowest ranking member of Red Dwarf) was assigned to Z shift under the command of Second Technician Arnold Rimmer (the second lowest ranking member on the ship). The anally-retentive Rimmer relished having someone underneath him to boss about, although the slovenly Lister only proved to torment Rimmer. This "graveyard shift" was occasionally and begrudgingly supervised by the Red Dwarf Second Officer Frank Todhunter, who had to deal with Rimmer's many complaints about Lister.
The two Z Shift workers, Rimmer and Lister, were also bunked up together, as crewmen of equal rank frequently were.
Z Shift dealt with cleaning the Vending Machines, such as making sure the nozzle was not clogged with chicken soup, and that the artificial intelligence of the Vending Machines was not wonky so that the Officers would get what they asked for. Z Shift also worked fixing "sticking" or jamming doors, repairing faulty "porous circuits" in the Botanical gardens, and other tasks deemed too menial for the Skutters - either because as Lister puts it, it was beneath the Skutters or because the Skutters have a better trade union than Z Shift. ("The End") Lister also worked Waste Disposal occasionally, jettisoning the garbage pods, but Rimmer never did this work. ("Waiting for God")
When Lister smuggled a pet cat aboard and got put in stasis as punishment, Rimmer was left alone on Z Shift. Rimmer therefore blamed Lister when Rimmer working alone did not repair a Drive Plate properly, resulting in the accident which killed the crew. Why such an important job was left to an unattended Rimmer is a mystery, however.("The End")
Three million years later, the boys from the Dwarf discussed going to rescue what they thought were "damsels in distress" from the Nova 5. Rimmer suggested that they pretend to be more than what were, since they were only qualified to unclog chicken soup dispensers and actually knew nothing about space adventuring. ("Kryten")
At Rimmer's eulogy, Lister said that the Universe had lost it's finest vending machine repairman, even though nobody ever got the correct item which they ordered from Rimmer's machines. ("Stoke Me a Clipper")
- The exact number who are a part of Z Shift varies depending on the source. In the novel Infinity Welcomes Careful Drivers, there are a number of technicians such as Petrovich who are a part of this shift.
- Although he appeared successful in his career, when he was mortally wounded Howard Rimmer admitted that he was not the captain but only the vending machine repairman aboard the Columbus 3, much like his brother Arnold aboard the Red Dwarf.
- It is revealed in apocrypha on the official website that the original captain of Red Dwarf, Frank Hollister, was also a vending machine repairman aboard the McGovern before defrauding his way to promotion.