A 1967 carriage, planted
Sidings
Thirty-one years on the Bakerloo line, then nine hundred pounds at the yard gate. It has not moved since.
What it is
Nobody set out to build a glasshouse.
Carriage 4308 was bought to be cut up for parts. It sat through one wet spring with the doors open and came back in June covered in enough volunteer growth that cutting it up stopped being the obvious thing to do.
Why a carriage
Glass on both flanks, steel underneath.
Sun comes in from either side for most of the day, and the steel floor holds what it collects until about ten at night. The door seals do the rest: humidity sits near seventy per cent with no vent motor anywhere in it.
What grows
Ninety-one species, fed off the roof.
Rain runs off the curved roof into two tanks slung under the bogies and is pumped back along the old luggage rail. Between April and October nothing in here is watered from the mains. Hart's tongue and lady fern took the shaded end on their own; the jasmine, the monstera and the plumbago were planted.
The rules
Twenty people inside at once.
Above that the humidity drops far enough to matter to the ferns, so entry is timed and the slots are short. There is no cafe, no shop, and nowhere to sit apart from the original moquette, which you are welcome to sit on.
The far door
It takes about twenty minutes to walk the length of it.
Most people take longer. The far door is left open onto the embankment, which is where the volunteer growth came from in the first place and where a good deal of it is still arriving.