Workers at BAE systems in Portsmouth today cut the first steel for the second stage of Portsmouth's involvement in building the Navy's new aircraft carrier HMS Queen Elizabeth.
A steel cutting ceremony at the Company's facility marked the official start of production on the stern section, referred to as Lower Block 05.
Portsmouth naval base commodore Rob Thompson pressed the button shortly after 11am.
Weighing over 1,000 tonnes on completion by April 2012, this section will house switchboards, air treatment units and the vessel's steering gear, as well as some accommodation areas.
The latest milestone in the Queen Elizabeth Class aircraft carrier programme follows the start of production on the forward section of the hull, Lower Block 02, which began in February of last year.
Steven Carroll, Queen Elizabeth Class Project Director at BAE Systems' Surface Ships division, said: 'Cutting steel on the second section of the hull here in Portsmouth in less than 12 months highlights the tremendous progress we are making on the programme to deliver the nation's flagships.
'The sheer scale of the hull as it takes shape in six shipyards across the country is a reminder that this is truly a once in a generation engineering project and we are all extremely proud to be a part of it.'
Work is underway at six shipyards across the UK, employing 8,000 people and thousands more across the supply chain.
Around 1,000 workers in Portsmouth are involved in the project.
In June, BAE Systems workers at the Naval Base will begin building island structures for the two ships and the pole mast, whilst integration and testing of the ships' complex mission system is underway at the firm's Maritime Integration and Support Centre on Portsdown Hill. Another team of BAE Systems engineers is testing the advanced communications systems for the ships.
HMS Queen Elizabeth – due to enter service by 2020 – was originally due to be completed by 2016 but this was changed in the government's Strategic Defence and Security Review last October.
Work on the second carrier, HMS Prince of Wales, is expected to start later this year. Initially, one of the carriers will be mothballed when they are handed over to the navy.