Each of these places had a staircase built allowing people to run down ot the tube line in the event of an emergency. (I you travel the line you can glimpse it in its siding)

A train sits on a siding on permanent standby in Central London, so that if a nuclear strike etc is imminent, everyone can be picked up swiftly. The Jubilee was also designed to be the fastest subway train on the line with the then fastest engine units.

The Line was built as an express line so it will not have to stop for other trains. Indeed, the longest stretch of underground track between two stations lies on this line at St Johns Wood.

Once it has left, central London, the train will sprint to the other end of the track to RAF Northwood which has the UK's central command bunker, the primary DUMB for the UK