Before the days of widespread telephone and radio usage, the watch desk in each station would be manned 24 hours a day. When a Box came in that they were due on, the watchman would manually sound the gong to wake everybody up. Later on, the gong was automated as well as the station lights.

There was also a log book at each watch desk in which the watchman would manually write down the box number, location, time and which companies rolled.

I know this system continued into the 90s sometime, long after the street boxes were removed. It was eventually replaced by computer terminals. While the numbering system is no longer in use in the same manner, the last time I listened to DFD radio, they still used the Box Alarm terminology when dispatching runs.