1972 Bakerloo line stock is not long for this world. We travel from Elephant and Castle to Harrow and Wealdstone, enjoying every last minute of these sassy old trains.
The air literally smacks of change at Elephant and Castle. The thick scent of Tarmac floats across what was recently a roundabout, and is currently a gooey puzzle for pedestrians to figure out.
And while the Elephant's facelift continues apace, there's another one going on beneath its skin.
TfL is already in the midst of refurbishing its 1972 stock Bakerloo line trains. The geometric moquette — smudged and ingrained with decades of dirt — will all be fresh and re-patterned by the end of this year.
Starting this summer, the hardy fleet gets a generous lick of paint, and by 2020 there'll be new interior body panel vinyl filming, while all those fat, round ventilation fans in the ceiling will have been replaced.
But it's all false comfort for these middle-aged troopers. TfL has already set a date for their funeral.
From the mid-2020s the Bakerloo trains will be usurped by the sleeker, more spacious (by 25%) models we're now used to being weaned onto. These will be the first air-cooled trains on the deep-level sections of the tube, and they'll probably be a darn sight more comfortable than what we've got now.
Retire, the 1972 stock must, but as commuters and Londoners we should lap up every last second of it; savour it like a fine, fusty vintage.
The Bakerloo line trains are now the oldest on the network. Though introduced in 1972, the stock was rushed off the production line, and is therefore near identical to the 1967 Victoria line trains, which said farewell in 2011.
You've got to hand it to the designers for sticking with the colour scheme. Everything about the Bakerloo line conjures a tobacco stained Basil Rathbone slouching in a worn Chesterfield and sipping a mug of Bisto. That's continued in the trains themselves — the shiny brown poles; the air vent knobs that look like chocolates; the seats topped with an icing of faux leather; those rust-coloured vertical armrests that defy all logic.
It's not just the colour that's deliciously outmoded.
When the trains are phased out, we'll also lose those seats that face into each other, and are so close together that your knees knock against those of the person opposite you. These wall-less compartments might be far from ideal, but they're a last vestige of golden train travel.
Coming into Baker Street we notice the roundel in the window that chides 'No Smoking'. OK, it's a pointless caveat these day, but we do wonder if the new trains shouldn't have 'No Vaping' signs for sheer nostalgia.
Another little anachronism we spot: the maps of the central London tube system are sized especially to fit into the very specific frames of this stock:
We're at Piccadilly Circus now — a station which gamely incorporates the Bakerloo line's gravy tones with a palette of red, green and fawn.
You can hardly say it succeeds, but still, this is the favourite Bakerloo station of self-confessed tube geek Simon Smiler. He loves the combination of the station's unusual platform layout and the crossover at one end of the station, offering unique trainspotting views.
Like us, Simon has a nostalgia for the rickety old Bakerloo trains: "The 1972 tube stock was introduced just when I started travelling to school by Underground," he says, "I liked them because they had a sleek space-age styling and made all the right noises."
Not so much anymore. Squeaking and shrieking its way north west, our first train gives in at Queen's Park: "That's enough, that's enough," it seems to pant, as we change onto a second, equally fossilised carriage.
If we're mad to get excited about a 50-minute odyssey across London, we're not alone. Simon took a valedictory ride on the last lot of stock:
"The 1938 trains used on the Bakerloo line included one 'standard stock' trailer. These dated from the 1920s or early 1930s.
"Knowing that they were about to be withdrawn and despite not even being a teenager at the time I made a point of riding in them."
The 30s stock Simon talks about has a smart, suburban sitting room feel about it — and can now be admired (and sat in) at London Transport Museum's Acton depot. But there's something special about the design of the current Bakerloo trains that makes them so easy on the eye.
Everywhere you look there are curves: the circular lights that flank the interior doors. The edge and tops of the seats. The strip lights that stay on, even in the broad daylight of Wembley, as if they're made by Volvo. And did we mention those strange seat dividers no one has ever understood?
This stock might be bedraggled but it's still got 60s/70s sass all these years on. Never again will we see a tube train that's so comfortable in its own wrinkled skin.
Soon enough, the 1972 stock will be shacked up in the depot alongside its 1930s predecessor. As the final fortunate few who still get to ride these trains for real we should take every opportunity to do so — from the Elephant to Harrow and back again. Pack a picnic and make a day of it.
In 10 or 20 years time, when you're in the museum depot with your kids, grandkids and great grandkids, they'll probably laugh when you point out the rattling old tin cans you had to make do with. Secretly though, they'll be jealous they never got a go on one.