I was astonished to read that in London, England, 'hundreds' of backhoe excavators, used to dig beneath existing houses to install capacious, opulent basements (sometimes on many levels), have allegedly been simply buried in place rather than go to the trouble of hauling them out of the ground again. (By the way, such equipment is known in England simply as a 'JCB', after the initials of the company that first made them there - just as we refer to a 'Xerox' when we mean a photocopy. The name of the company has become synonymous with its product.)
The Telegraph reports:
Future archaeologists digging for artefacts in London will blink, baffled, as they try to make sense of the earth-moving machinery buried under a garden in Chelsea. I suspect that even the most canny will never guess the true explanation for such finds: all over the capital’s choicest areas, hundreds of JCB diggers have apparently been buried in their own holes once they have completed their task. Given London’s exorbitant house prices why bother with the expense and hassle of retrieving a used digger worth only £35,000 [about US $59,000] when a new basement will have added hundreds of thousands to your property?
Planning restrictions in posh neighbourhoods such as Chelsea, Belgravia and Notting Hill won’t allow for building upwards. As a house is the average Briton’s number-one asset, home owners are keen to increase their investment by digging as far down as their pockets can afford. They need nerves of steel to carry out their expansion, I should point out. Few things threaten local friendships and networks more than the decision to extend downward. “How far did you go?” was in my teens the question your prying BF asked about your date. Today, it’s asked by neighbours when they see scaffolding go up in front of your house: how far down are you digging?
. . .
Though most home owners have calculated how much a basement extension can add to the value of their house, Henry Pryor, the property-finder we always see on television, warned that many people underestimate how expensive mining the ground for more space can prove. But he also admits that “with property prices breaching £10,000 [just under US $17,000] a square foot, the sums add up”. Thanks to countless archived articles and TV programmes, future archaeologists will be familiar with the homeowning neurosis that characterises 21st-century Londoners. As they dig beyond the JCBs to find spacious, cavernous rooms far, far beneath the ground, future scholars will study their contents for a clue to the life led by an elite as exotic and unrepresentative of their fellow citizens as the rich Pompeiians who boasted running water and heating.
There's more at the link.
I've heard of tunnel boring machines, costing many millions of dollars, being abandoned in place because it would cost more to bore another tunnel to get them out of the ground than it would to leave them there. Their vast expense is effectively written off as part of the project's capital budget. However, I've never heard of the same being done with the small excavators used in domestic home expansion! I'd much rather bring in a crane to haul it out, and recover the almost $60,000 value of the machine (as quoted in the article).
(On the other hand, if you leave it inside the newly constructed or expanded basement, you can at least dig your way out again if anything goes wrong!)