A couple of friends in my younger days were on a daft shift pattern of alternating 12 hours 6 to 6 but with a fast turnover from days to night. Their job was also fairly dull but required some level of attention so they did no end up chewed by an extruder. They relied heavely on chemicals of the non prescribed variety (uppers to stay awake than downers once back home to go to sleep). Having witnessed the effects I can't say I'd recommend it. Shifts is the main reason why Him Indoors is not keen on an LAS career for me. What sort of a sleeper were you before you started working for the NHS (if you can remember that far) ?