Defence correspondent David Bowden has an exclusive peak at how construction of the HMS Queen Elizabeth is progressing.
They will be the largest warships ever built for the Royal Navy, each weighing 65,000 tonnes and with their length equal to 28 London buses.
Now the hull of one of these two mammoth aircraft carriers, HMS Queen Elizabeth, will be in one piece for the first time as construction continues in Scotland.
Sky News was given exclusive access to the site Rosyth just outside Edinburgh as the latest phase of the £5.5bn project was being completed.
HMS Queen Elizabeth is the first of two new aircraft carriers being put together there.
The carrier, which is three times the size of any Royal Navy ship now in service, has been built in modules at shipyards across the country.
Its final assembly is using the heaviest lift crane in the UK, itself built specially for the project by the Chinese and nicknamed Goliath.