Post by David Wailing on Jun 17, 2016 13:19:30 GMT
When travelling on the northbound Piccadilly Line, there is a fairly long gap between Manor House and Turnpike Lane. At around the halfway point, there is always a sudden burst of wind accompanied by a faint cloud of dust blown through the train. This is especially noticeable if you're travelling in the first car. It feels like the train has just burst a large air bubble.
Does anyone know the cause of this?
I've noticed it many times (literally hundreds of occasions, since I live at Wood Green) and it is very consistent. Every time it happens I think I must ask someone, but always forget. So I'm finally asking!
As the train approaches the ventilation shaft the pressure in front of it will decrease as there is a path for the air it is pushing. This will cause any currents of air in the train to gradually decrease until it passes the shaft, at which point the pressure will rapidly increase, causing a noticeable change in air currents.
Interesting about the dust, though.
I don't think I've ever noticed a dust cloud in an underground train.
you can occasionally see clouds of dust anywhere on the system , especially after engineering work, I am surprised that dust remains in the same area though.
When working as a guard on the northern line many years ago, in the days of white shirts, there was no question of going out after work without having a shower first, the water used to be black around your feet and when you blew your nose there was no trace of green for all the black. It is a lot less dusty now because of different braking systems.
Last Edit: Jun 23, 2016 19:46:03 GMT by superteacher: Baking changed to braking!