It sounded like a rail union ploy. Or an oversight by Transport for London. More likely, though, a message over a station Tannoy.

“One of the drivers is complaining that the wheels aren’t round,” said Charlotte, line controller of the “Pic” (Piccadilly line).

But apparently it’s a thing. If there wasn’t enough to think about when travelling by train – that gap won’t mind itself – now we have to worry about flats.

A mobile train technician informed The Tube: Going Underground (Channel 5) that flats occur when a train skids, perhaps on the wrong kind of leaves, wearing the wheel.

Off to the workshop the train goes for a trim, leaving Charlotte with her 1973 rolling (or not) stock even more depleted as crisis approaches.

Usually it’s swooping camera shots from great heights that make my palms sweat but here it was flashbacks to Bank/Monument station on DLR strike day.

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I went all Curious Incident Of The Dog In The Night-Time, reciting the nerd stats for comfort. 430 escalators on the system. Angel the longest at 60m. Trains travel six times round the world in a day.

Two million passengers a week use Bank’s 10 platforms. 1,000 people per train. Trains stop at a station for 60 seconds.

If you want proper logjam, head to Washington. Tears pricked the eyes to see Barack Obama in 2008 offering hope and promising change.

Within days the banks went into meltdown and so collapsed his agenda.

The excellent documentary Inside Obama’s White House (BBC) laid bare the staggering institutional inertia built into the checks and balances of executive and legislature in the US – White House: irresistible force; Capitol: immovable object.

Much like the Pic, there is light at the end of the tunnel, though. If the President can’t achieve anything, then we need not fear a Trump presidency quite so much as billed.