Giant gas platform sunk: Time-lapse footage
5 August 2013 Last updated at 19:35 BST
A gas platform the size of a football pitch has been sent plunging to the bottom of the ocean, 200km (125 miles) off the coast of Norway.
It will house a giant compressor claimed to be the world's biggest offshore machine.
The Statoil equipment has been designed to pump some $30bn (£20bn) worth of gas from a depleted gas field.
Time-lapse footage shows the platform disappearing beneath the waves. Roger Harrabin reports.