I am writing a short story set in a lighthouse in England, UK. At one time lighthouses were manned by two men at a time, but because of a case where a keeper murdered his fellow keeper, Trinity House (I think) brought in new rules whereby there had to be three keepers at a time. I remember reading about all this about ten years ago.
I cannot find details of the case in question (not important) but likewise I can't find anything about exactly when the rules changed. This is an integral aspect of the plot which I need to know in order to set the story in the correct time period, and I would be very grateful if anyone knew the answer to this or who can point me to where I can find out.
Thank you. :)