I feel I'm probably teasing you all a bit by not saying much
I'd slightly rejigged the start of my route to include the well-known trick of waiting at Farringdon for the correct sequence of trains to come up on the board. But actually, when I got to Farringdon and quickly popped out to get some water for the trip, I got back on the platform and saw that the train in was the first of the exact sequence i needed! Hastily jumping on and just about getting my stopwatch out in time, I started on my way and of course all my changes were very easy going up there. When I headed underground at Liverpool Street the connections just got scarily good. I got to Bank and on my way down to the drain there were people coming up the travelator so I pegged it down and just made a train, which makes it the first time i've not had to wait for one there!
So with that whole rubbish section of the network out of the way, it was fast and furious to get the other 6 lines done. After getting lost at Embankment last time, I'd popped by there on my way to the start to make sure I'd know where I was going, and once there this time I had only a 1 minute wait for a District line even though according to the service status at the time there severe delays on this line!
The rest of my connections were simply unbelievable, I only waited for one train at Oxford Circus and the rest of the time they were either already in or just coming. So with the watch ticking towards that 40 minute mark I arrived at the Picadilly platforms of Picadilly Circus, but having an eastbound train close its doors on me, I thought the 40 minute time was beaten. Just then, in comes a Westbound and as i got on and watched the seconds go by I just hoped the driver would get a move on! He/she obviously did, and that final leg to Green Park only took 69 seconds!
Anyway, in such a short challenge i've probably given away a lot of my route in there, but if anyone wants to see my timings i'd be happy to show them
