Ports and rail
The vest that stayed in the van
The scene
Quarter to six in the morning, still dark. The terminal has not stopped all night: engines, reversing alarms, steel on steel. A maintenance technician is going to make a quick adjustment on a set of points, five minutes at most, and he wants to be done before daylight and the first traffic. He steps out of the safe zone and onto the shunting track. His hi-vis vest is on the van seat, forty metres away.
Where it breaks
There are cameras pointed at that track. They are recording, like every night. But recording is not watching: the video goes to a disk nobody opens, and at that hour nobody is assigned to that screen. Normally that disk only gets opened if something happens or an inspector turns up.
What happens
The technician steps over the yellow line and crouches over the points. Eighty metres away, a shunting locomotive starts to move. His back is turned and he is wearing ear defenders: he cannot hear it, and with no vest he is just one more shadow among the steel.
With IRIS
IRIS watches that track the whole time, quarter to six included. It recognises a person, sees that he has crossed the yellow line, and sees that he is not wearing a vest. That meets the rule Safety set, so IRIS speaks up: to the shift supervisor, with the camera, the place and the time, and, if you want, over the tannoy in that zone too. The supervisor decides, calls it in on the radio and stops the movement. Nobody had to be watching that screen for this to happen.
Safety stops being something you check after the accident and becomes something you check while the technician is still on the track.