Interesting on the underground brake dust issue Alistair.
I have no idea of the technology involved in the design of current underground rail road stock but would have thought that someone somewhere might have designed something in to utilise the "over run" aspect of the drive motors to reduce brake dust.. even if stored to power on board lighting or even to as a last resort to dump into resistance to loose as heat... But then chances my line of thought is one that may have been followed many years back and plays a part in the design as it is today, just that brake dust was thought to be no big deal back then, as it seems to be today for the snow flakes we seem to have become...
