HMS Audacious is the fourth Astute-class

Astute class submarine

The Astute-class is the latest class of nuclear-powered fleet submarines in service with the Royal Navy. The class sets a new standard for the Royal Navy in terms of weapons load, communication facilities and stealth. The boats are being constructed by BAE Systems Submarine Solutions at...

 nuclear-powered fleet submarine

Submarine

A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

 of the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

. Long lead items for its construction were ordered on 28 August 2006 although the actual order was not placed until 21 May 2007. It is currently under construction.

Some aspects of A-04 will be different from Boats 1-3. Changes include the External Communication System (ECS) which will be upgraded.

Nuclear power

Audacious's nuclear reactor will not need to be refuelled during the boat's 25 year service. Since the submarine can replenish her air supply and purify water underway and while submerged, she will be able to circumnavigate the planet without resurfacing. The submarine's main limitation will be from the three months supply of food carried for the 98 officers and ratings.

Stealth

The Astute class SSN

SSN

SSN may refer to:*Scoil an Spioraid Naoimh, a primary school in Cork City Ireland*Secure Service Network, a network behind a firewall or IPS containing systems which can be accessed from both the internal and external networks, but cannot reach the internal network*Streaming Sports Network, an...

s are designed as the most stealthy Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 submarines in history. Using advanced stealth technology Astute "makes less noise than a baby dolphin, making her as good as undetectable by enemy ships."

Weapons

Audacious will carry a mix of 38 weapons in six 21-inch (533 mm) torpedo tubes;

• BGM-109 Tomahawk
  BGM-109 Tomahawk
  The Tomahawk is a long-range, all-weather, subsonic cruise missile. Introduced by General Dynamics in the 1970s, it was designed as a medium- to long-range, low-altitude missile that could be launched from a surface platform. It has been improved several times and, by way of corporate divestitures...
  
   Block IV cruise missiles. Range of 1350 nautical miles (2,500.2 km).
• Spearfish torpedo
  Spearfish torpedo
  The Spearfish torpedo is the heavy torpedo used by the submarines of the Royal Navy. It can be guided by wire or by autonomous active or passive sonar, and provides both anti-submarine warfare and anti-surface ship warfare capability.It replaces the unreliable Tigerfish torpedo, which was...
  
  es.

External links

• Navy Matters - Astute Class