So maybe it was smoke that I smelt - or even both smoke and then creosote. I saw that other passengers on the train also smelt whatever it was. This included several ladies who held their noses and created facial expressions that suggested that they were most displeased.
I was not displeased, as I do not mind the smell of creosote somewhere where it would be appropriate - such as wooden railway sleepers, wooden fences, etc.
At about 2am there was a trespass incident where the individual concerned set fire to some equipment in one of the tunnels and was then unable to be found, rumour has it that he hid on top of one of the cable runs that go over the track. There were engineers trains on their way to Leytonstone and the last few eastbound trains behind them.
The fire wasn't put out until 7am meaning the engineering works hadn't started yet and really needed to get going so the possession was taken and work started. The possession started from Bow substation trapping a train at Stratford and also at Leyton. There was also at least one more train trapped at Mile End which had to do a wrong directional move back to Bethnal Green.
And some of the work was cancelled to make sure they were able to hand over on time for Monday morning.