London's property bubble has got people energetically expanding their property, digging out sub-basements — and the insane bubblenomics of London housebuilding are such that it's cheaper to just bury the digger and abandon it than to retrieve it. London's accumulating a substrate of entombed earthmoving machinery.
A new solution emerged: simply bury the digger in its own hole. Given the exceptional profits of London property development, why bother with the expense and hassle of retrieving a used digger – worth only £5,000 or £6,000 – from the back of a house that would soon be sold for several million? The time and money expended on rescuing a digger were better spent moving on to the next big deal.
The new method, now considered standard operating practice, is to cover the digger with "hardcore", a mixture of sand and gravel. Then a layer of concrete is simply poured over the top. Digger? What digger? The digger has literally dug its own grave – just as the boring machines that excavated the Channel Tunnel were abandoned beneath the passage they had just created.
How many of these once perfectly functioning and possibly still serviceable diggers are petrified underneath central London, like those Romans preserved cowering in the corners of houses in Pompeii? Estimates vary. One property developer I asked reckoned at least 1,000; another put the figure at more like 500. In some of London's newest luxury conversions, "sub-basements" are being tucked beneath the existing basement conversions. But developers are stumbling on a new kind of obstacle as they burrow deeper still: abandoned diggers from the last round of improvements.
The bizarre secret of London's buried diggers [Ed Smith/New Statesman]
(Image: Big machine at work, Adelle Roux, CC-BY-SA)