An explosion in the number of basement extensions in London has left a bizarre legacy: according to property experts there could be up to 1,000 JCBs buried underground. Apparently, after the diggers have finished excavating space for the underwater pool and cinema room, they are simply left underground.

So how can this possibly make financial sense?

The weird legacy was uncovered by the New Statesman, which claims that £5 million worth of machinery has been buried under London streets and gardens in the last 25 years. Developers it spoke to put the number of diggers buried underground at between 500 and 1,000. The Telegraph pointed out that in Kensington and Chelsea alone in the five years to 2013, there were 800 planing applications for basement conversions, so these numbers seem quite realistic.

The problem is that these extensions go so deep that the diggers cannot be driven out of the hole they have created. One option is to get hold of a crane to life the digger out, but when the developers did the maths they decided it didn’t make sense. To get the digger back they would need to hire a crane and get the street closed for the day – both of which are expensive and unpopular. It also used up time and resources that could be otherwise spent moving onto the next multimillion pound project. For a £5,000 digger it was simply not worth the money.

It’s hard to imagine that these diggers have no scrap value. While it may not make sense for a developer to bring the digger out in one piece, you have to wonder whether there isn’t anyone willing to climb into the hole and bring more manageable chunks to the surface for sale as scrap or for parts.

Instead, they remain ready for highly confused archaeologists to dig them up in future years and wonder why we felt the need to bury diggers next to our homes.
Buried under London

However, they’re not the weirdest thing to have been buried under London.

We reported last month on the home in Teddington, south London, which had been snapped up despite the fact that the previous owners had been buried in the back garden.

During the digging for Crossrail, some unusual things have been discovered. These included medieval ice skates found at Liverpool Street and a Victoria chamber pot found in Stepney Green featuring the words ‘when you want to piss, remember they who gave you this’, and flints from the stone age found in North Woolwich.

When the expansion for Kings Cross Station was being built, the old burial ground at St Paul’s Church was dug up, including 1,500 bodies. In one of the coffins they found walrus bones… although inexplicably it wasn’t an entire walrus.

There are all sorts of engineering feats down there too. One of the less well known is the Tower subway. This is a tunnel under the Thames just downstream of Tower Bridge. It was built in 1869 to help people cross the river. However, after the bridge was built a couple of decades later it became redundant, so it was closed off. The tunnel is used today to carry cables and water pipes.

A deep level bomb shelter was built at Goodge Street, and used by Eisenhower in his role as Supreme Commander of the Allied Forces in Europe. The shelter was abandoned in 1956, and is currently used by an archive firm.

Then there are the well-known buried buildings which remain impressive – including a huge number of abandoned tube stations and the Cabinet War Rooms, buried under Whitehall, which were used by Winston Churchill in the most perilous days of the war.