In Dublin when I was a child (1950's), on building sites and in areas where the Dublin Corporation was undertaking civic works, a night watchman would be employed as a sort of security guard. These watchmen would have a watchman's hut and a coke-burning brazier to keep warm and to boil up their billy-can for tea. My memory of a watchman's hut was that they were of similar size, shape and construction as a sentry box, but inside there was a wide plank bench used as a seat. The watchmen were invariably old and illclad and would nip down to the boozer for a pint at every opportunity. Everybody young or old always refered to them as "the gotchie" and I always presumed it was a humourous term derived from their supposed cry of victory when they apprehended young-fellas that were up to no good "I've got ye, I've got ye" which in a Dublin accent might come out as "I've gotchie"

Fergus