Dirty Great Machines

Documentary series revealing the demon diggers burrowing below our cities. In London, a tunnel boring machine faces immense challenges as it takes on Britain's deepest-ever tunnel. Meanwhile in Mexico, a giant mechanical worm makes the earth move just metres beneath the city's soaring skyscrapers.

We meet the largest land-based machines ever built - bucket wheel excavators. Their mission is to peel back the surface of the earth with each turn of their colossal parts but when you are battling mother earth, the fight is far from easy.

We climb aboard monster maritime machines that go where others fear to float. Man's desire for natural resources is insatiable, whether it is to power our homes, fuel our cars or build our skyscrapers, but with reserves on land running dry, we are now looking to the oceans to satisfy the needs of 21st-century living. This programme showcases the cutting-edge machines at the forefront of this assault.

Meet the machines that are making mincemeat of the hardest rocks on the planet. Almost two miles underground in the Kidd mine in Canada, the mighty ITH drill is chewing through rock, to enable the extraction of copper and zinc. In Finland, the Jumbo Tunneller is boring through granite to excavate a new metro tunnel to improve Helsinki's commuter services.