Just two weeks ago, the brand new HMS Queen Elizabeth aircraft carrier was handed over to the Royal Navy. It’s the biggest ship the navy has ever had and has a flight deck the size of three football pitches. For £3.1 billion, you might it expect it not to leak. But it turns out it is taking on 200 litres of water an hour. That is not a huge amount, say its new owners, but it is certainly embarrassing for the navy.