Great Northern 313 over door sensors

[psychopompos]

I've been a regular on Great Northern between Highbury&Islington and Moorgate for a couple of years, but only recently noticed that the trains have some sort of sensor above the doors. Three black rectangles, with a couple of of red lights which light up when there's someone or something directly under the sensor. I don't often ride trains other than Great Northern and London Over/underground, but I don't recall seeing this anywhere else. Any idea what it's for?

 

[swt_passenger]

I've been a regular on Great Northern between Highbury&Islington and Moorgate for a couple of years, but only recently noticed that the trains have some sort of sensor above the doors. Three black rectangles, with a couple of of red lights which light up when there's someone or something directly under the sensor. I don't often ride trains other than Great Northern and London Over/underground, but I don't recall seeing this anywhere else. Any idea what it's for?

Automatic IR passenger counting equipment sound the most likely, from your above description. A subset of SWR’s Desiro fleet have them, which match your description.

Welcome to these forums...

 

[psychopompos]

Automatic IR passenger counting equipment sound the most likely, from your above description. A subset of SWR’s Desiro fleet have them, which match your description.

Welcome to these forums...

Thanks for the welcome.

I'll try to snap a picture one of these days. Would the idea be to count how many passengers enter and exit the train, or whether it's crowded enough for there to be someone standing under the sensor for a long time? If it's the former it'd be seriously distorted at peak times, unless it's perhaps disabled when the doors are closed.

 

[swt_passenger]

Thanks for the welcome.

I'll try to snap a picture one of these days. Would the idea be to count how many passengers enter and exit the train, or whether it's crowded enough for there to be someone standing under the sensor for a long time? If it's the former it'd be seriously distorted at peak times, unless it's perhaps disabled when the doors are closed.

I think the purpose is to count movement through the doors, and in that case it would be logical to only operate while doors are open. I believe that in SWR’s set up they act as an accuracy or calibration check of the passenger load weighing equipment that is fitted in all the trains.