A modern engineering masterpiece - the nuclear sub that will go 25 years without refuelling
By Loz Blain
May 20, 2007
May 21, 2007 A hulking 100 metres long, the Astute is the largest, most heavily armed, stealthiest and most sophisticated submarine ever built for the Royal Navy. The massive nuclear sub, which will never need refuelling in its 25 year service life, is able to circumnavigate the globe underwater, producing its own fresh water and air for the crew - and its range is only really limited by the need for fresh food supplies. From every angle, it is an engineering masterpiece, spoken of as one of the great engineering achievements of all time and more complex than the space shuttle. Britain's Royal Navy is set to launch this new flagship in less than a month.
The Astute's launch on June 8th at the BAE Systems Shipyard in Barrow-in-Furness is highly anticipated, and with good reason: it's the biggest and most powerful sub the British Royal Navy has ever commissioned. When fully stored it will displace around 7800 tonnes of seawater (around as much as 65 Blue Whales or 1,000 double-decker London buses) - and yet it will operate on a much smaller crew than any previous sub has required.
She will be Britain's most heavily-armed sub by far; 6 weapons tubes and a storage capacity of 38 Spearfish torpedoes and Tomahawk cruise missiles with a massive 2,000km pinpoint strike range. As such she is expected to be used mainly in support of ground operations and intelligence missions.
The world's most advanced sonar system, coupled with a range of visual equipment like thermal imaging cameras, low light video and CCD TV sensors, combine to negate the need for an optical periscope. In the right conditions Astute will be able to lie submerged in the English Channel and detect the QE2 leaving New York harbour.
39,000 acoustic tiles will mask the vessel's sonar signature and help to make her the most stealthy sub the Royal Navy has ever operated. With a radar signature equal to that of a dolphin, it should be able to remain undetected hundreds of metres underwater and thousands of miles away from home.
Astute’s state-of-the-art pressurised water reactor is more complex than a nuclear power station, with more restrictions placed upon it: it must be engineered and operated in the knowledge that almost 100 people live and work in close proximity - the submarine commander sleeps less than 10 metres away from the nuclear core.
Once deployed, Astute is designed not to require refuelling throughout her 25-year service life. It can produce oxygen and water indefinitely, can purify the onboard atmosphere by removing carbon dioxide, hydreogen and carbon monoxide, and it's limited to a patrol length of 90 days at a time only by its ability to carry food for the crew. It compacts and carries its own garbage for disposal on land.
Construction of this mammoth submarine has been fascinating in itself - with more than a million components, a nuclear power source and the necessity to withstand huge pressures, the Astute is being viewed as one of the most challenging engineering projects in history.
Defense contractor BAE Systems, who have taken on the UK£3.5 billion project of producing at least 3 of these class submarines, learned a lot from USA-based submarine constructor Electric Boat. One of the first subs to be designed entirely in a CAD 3-D design environment, no actual prototypes were built in the design stages. Sections of the vessel were built vertically, saving manpower, and the Astute's sophisticated modular design shortened the engine installation time from 2-3 days down to 5 hours.
As is fairly typical with government contracts, it has run well over budget and is currently four years behind the original schedule - but the scheduled launch next month should be a spectacular demonstration of a wonderful engineering achievement.