The Astute is seen as the most advanced submarine yet

Looming above us is a construction shed 12 stories high. Within it are three nuclear-powered submarines at different stages of construction.

And as a huge, red neon sign reminds the workforce, the first o­ne is now just 32 days away from launch.

But to judge by the scaffolding surrounding it, it's hard to believe it's going to be ready o­n time.

"I'm determined it will be," says operations director Nigel Ward. "However it's a nuclear submarine, and lots of things can go wrong."

Secrets intact

Under all its covers, Astute is a technological phenomenon. Its nuclear reactor means it'll never need refuelling in the whole of its 25 year life.

Dummy missiles are used during the building work

Since it makes its own air and water, it can circumnavigate the globe without needing to surface.

And its weapons systems are so accurate that were it positioned in the English Channel, its cruise missiles could pinpoint targets as far away as North Africa.

Indeed, down in the weapons room it looks like a Tomahawk cruise missile is already waiting to be loaded into o­ne of the torpedo tubes.

"It's o­nly a dummy" says the man who's keeping a close eye o­n us. His job is to stop us photographing anything that might give away some of Astute's secret capabilities.

Reduced requirements

It may be o­ne of the most sophisticated submarines ever built, but the project has been beset with problems. The three submarines are £900m ($450m) over budget and four years behind the original schedule.

Astute facts Cost: £3.5bn for three subs Weight: 7,800 tons Length: 97m Time to build: 6 years 4 months Power: pressurized water reactor, fuelled for life Crew: 98

But a new boss at Barrow, Murray Easton, introduced big changes when he arrived a few years back.

A team of psychologists was brought into the yard to improve management effectiveness, and to create better ways of communication. Even now a psychologist is present at every board meeting.

Another big innovation, learnt from the America submarine-builder Electric Boat, was to build sections of the submarine vertically rather than horizontally. Equipment can be lowered in with the help of gravity, cutting the need for manpower dramatically.

Future missiles

It all leads to a prouder, more committed workforce.

The building project is enormous

"We needed help over Easter," says Nigel Ward, "and over 300 men volunteered to work, even though the weather forecast was good."

Workers are also enthusiastic about what they have built.

"It's a fantastic product," says Andy Ogden as he stands near the conning tower of Astute. "And something the Navy will be extremely proud of when they get their hands o­n it in a year's time."

Three-and-a-half thousand other workers have a vested interest in such customer satisfaction.

Because if all goes according to plan, they'll be rewarded with contracts to build four more Astute submarines, and eventually the submarines that will carry the next generation of Britain's nuclear missiles.