HSBC internal mail system

[gaz_farr]

Hi I saw on a documentary on the National Geographic Channel (i think) about the HSBC Hq in Hong Kong. In it they showed the system used for delivering Internal mail which basically looked like a model railway only it went up walls and allsorts. Does anyone know of any website that contains details about this system - i've tried googling but with no luck. i was telling one of my managers and I got the impression they didnt believe me

[Fitzer]

BP used to have a similar system in their London office complex in the '80s when I worked there. The little trucks had toothed wheels and ran in a a track a bit like the guide rails in a dishwasher (sorry can't think of a better analogy) except that there were corresponding teeth in the tracks. You could program the trucks for their destinations which was essentially a letter and number indicating which floor of the building and which post point on that floor. No idea who made the system but it was obviously planned from before the building was built as the tracks ran in spaces inside the walls.