Ports and rail
The vest that stayed in the van
The scene
Five forty-five in the morning, still dark. The terminal hasn’t stopped all night: engines, backup alarms, steel on steel. A maintenance technician is going to make a quick adjustment on a set of points, five minutes at most, and wants to be done before daylight and the first traffic. They step out of the safe zone and onto the switching track. The safety vest is on the van seat, a hundred feet away.
Where it breaks
There are cameras pointed at that track. They’re recording, like every night. But recording isn’t watching: the video goes to a disk nobody opens, and at that hour nobody’s 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 yards away, a switching locomotive starts to move. Their back is turned and they’re wearing ear defenders: they can’t hear it, and with no vest they’re just one more shadow among the steel.
With IRIS
IRIS watches that track the whole time, five forty-five included. It sees a person, sees that they’ve crossed the yellow line, and sees that there’s no 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 PA 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.