Why doesn't the sparks from the London underground trains cause explosions???

Question

When the tube moves you get blue sparks (i like sticking my head out between carriages lol) under the train. Whats the difference to those sparks and say a lit cigarette........Didnt a spark from a faulty escalator cause an explosion 10-20 years ago?? So im asking why doesn't the train sparks have the same effect???

Answer 1

Only if all the people farted. at the same time in the tube.  

Answer 2

The London underground being electric does not give off any fumes which will ignite from the sparks hence no explosion is possible.

EDIT: You can't smoke in the stations as it is illegal in the UK to smoke in an enclosed public place, Restaurants, cafes, pubs etc. As the underground is enclosed you can't smoke there.

Answer 3

Just a comment really - you say that you never could smoke down tube stations. Not true, you are obviously fairly young. You were able to smoke down there (and any where else for that matter) many years ago and at that time each platform would have had at least one ciggy vending machine on it. 40 years back if you were a non smoker you were in the minority.

Anyway, regarding the sparks - what would they ignite? Its all concrete down there.

Answer 4

The answers which refer to 'no combustible material' are nonsensical because there is plenty of combustible material in the tunnels. The reason why nothing catches fire from the arcing (the 'blue flashes' you refer to) is because that it so quick, it is not like a smouldering cigarette end. You are correct that such started the King's Cross fire in 1987. After that smoking was banned on all enclosed or underground parts of railway systems. This was prior to the general ban on smoking in enclosed spaces.

Answer 5

Seriously, if there is ever a gas leak or some type of explosive fuel that accumulates down there, the sparks will set off an explosion.

Answer 6

because there has to be a thing to explode or set fire to eg. gunpowder ,wood, chemicals

Answer 7

The escalator fire at Kings Cross in 1987 was caused by a discarded cigarette lighting all of the c**p that was under the escalator & had never been cleaned.

As above, the spark would need to ignite a source of fuel, such as petrol or gas: The underground is run on electricity, so there are no readily combustible fuels to ignite.

Answer 8

The air supports combustion but isn't explosive. Sparks from electric trains actually do sometimes start fires, but that is on the surface rail where there are sometimes dried plants, rubbish, or wooden rail guards near the live rail.

Smoking is banned in all tube stations because unlike a spark which is only for a split second, a discarded cigarette end can smoulder for a long time and ignite combustible waste. That's how the King's Cross fire started.

Incidentally, the worst danger from 'sparkers',. (i.e. electric trains) in Britain came during the war, when Luftwaffe planes were flying overhead and dropping bombs.

The sparks from an electric train at night can light up the surrounding countryside like a flash photo - so much for the 'blackout'.

Answer 9

a fire the same as an explosion requires three things fuel,heat and oxogen an explosion just moves at a much faster rate than a fire so just think about it and you will work it out