17 miles of construction deep below ground... It's a bunker! When the EU project finally and inevitably collapses, taking the economy of Western Europe with it, the corrupt, incompetent and eye-poppingly expensive politicians and bureaucrats are going to need a hidey-hole.
But what about the pipes and cables?
We saw them as Professor Brian Cox tootled along through the circular cavern, didn't we? D:Ream on. What we saw was a CGI loop, entirely familiar to computer games players. Beneath this illusory overlay is footage of working, sleeping and recreational facilities, water filters, air recycling machinery, food stores and all the rest. Like Slartibartfast on his planet-constructing world of Magarathea, the Euro elite will be able to sleep through the coming recession and return in time to impose fresh taxes and regulations.
Meanwhile, the border-straddling tunnel is a convenient way for them to pop across to Switzerland and check their bank accounts.