Taking 14 years to design and build and costing around £1bn ($1.6bn) , the British nuclear submarine Astute is one of the most technologically advanced and controversial machines in the world. Weighing in at 7,000 tonnes, measuring 100 metres (330ft) long and boasting three decks, how do you put such a craft together?
For over a year, the BBC filmed the submarine’s construction inside one of the most secure and secret places in the UK. They met the people working on it, and went inside the construction of the submarine itself, shedding light on the ship’s design, life-support systems and weaponry.
But the story took a dramatic turn. An unforeseen event meant the submarine had to sail into the open sea for the first time during one of the wettest and windiest weekends of the year.
The film is part of the BBC documentary series Voyages of Construction, looking at the technology behind large engineering projects.