Sunday, September 11, 2011

Queen Elizabeth Class Aircraft Carrier

Queen Elizabeth Class Aircraft Carrier

The Queen Elizabeth class aircraft carriers (formerly the CV Future or CVF project) are a two-ship class of aircraft carrier being built for the Royal Navy. HMS Queen Elizabeth is expected to enter service in 2020 and HMS Prince of Wales is expected to initially be kept in a state of "extended readiness" after completion. HMS Queen Elizabeth will be built to a CATOBAR configuration. The construction of HMS Prince of Wales was assured by the 2010 Strategic Defence and Security Review, although its role in the immediate aftermath of its commission remains uncertain. The vessels will displace about 65,600 tonnes, be 284 metres (932 ft) long and have a tailored air group of up to 40 aircraft. They will thus be by far the largest warships ever to be constructed for the Royal Navy.

The contract for the vessels was announced on 25 July 2007 by then Secretary of State for Defence Des Browne, ending several years of delay over cost issues and British naval shipbuilding restructuring. The cost was initially estimated to be £3.9 billion. The contracts were officially signed one year later on 3 July 2008 after the creation of BVT Surface Fleet through the merger of BAE Systems Surface Fleet Solutions and VT Group's VT Shipbuilding which was a requirement of the UK Government.

Queen Elizabeth Class
Builders: BAE Systems Surface Ships
Thales Group
Babcock Marine
Operators: Royal Navy
Preceded by: Invincible class
In service: 2020 and 2023
Building: 2
Planned: HMS Queen Elizabeth
HMS Prince of Wales
Completed: 0
General characteristics
Displacement: 65,600 t (64,600 long tons)
Length: 284 m (932 ft)
Beam: 39 m (128 ft) (waterline)
73 m (240 ft) overall
Draught: 11 m (36 ft)
Decks: 16,000 m2 (170,000 sq ft)
Speed: +25 knots (46 km/h; 29 mph)
Range: 10,000 nautical miles (19,000 km; 12,000 mi)
Capacity: 1,450
Complement: 600
Sensors and
processing systems:
  • Thales S1850M Long range radar
  • Ultra Electronics Series 2500 Electro Optical System (EOS) and Glide Path Camera (GPC)
Armament: Phalanx CIWS
30mm guns and mini-guns to counter asymmetric threats.
Aircraft carried:

Tailored air group of up to 40 aircraft:

  • F-35 Lightning II
  • Chinook
  • Apache
  • Merlin
  • Lynx Wildcat
  • Maritime Airborne Surveillance Capability (MASC) - Airborne Early Warning aircraft
Aviation facilities: one large flight deck, a Hangar below deck and two sizable aircraft lifts.

Queen Elizabeth Class Design

The vessels will displace approximately 65,600 tonnes each, over three times the displacement of the current Invincible class. They will be the largest warships ever built in the UK and the most capable aircraft carriers outside of the U.S. Navy. Nothing of the scale has been proposed for the Royal Navy since the cancelled 1960s CVA-01 programme. Giving evidence to the House of Commons Defence Committee, the First Sea Lord Admiral Sir Alan West explained that interoperability with the United States Navy was a factor in deciding of the size of the carriers as the firepower of the carrier's airwing:

for a deep strike package, we have done ...quite detailed calculations and we have come out with the figure of 36 joint strike fighters ...that is the thing that has made us arrive at that size of deck and that size of ship, to enable that to happen.

I have talked with the CNO (Chief of Naval Operations) in America. He is very keen for us to get these because he sees us slotting in with his carrier groups. He really wants us to have these, but he wants us to have the same sort of clout as one of their carriers.

The design features two small island structures, one devoted to ship navigation, and the other to air operations. This allows optimal placement of bridges for both tasks: navigation calls for a bridge placed forward (as on the Charles De Gaulle), while air operations are made easier with a bridge placed aft (as seen on the US Gerald R. Ford class aircraft carrier). Two deck lifts will be used, both on the starboard side.

Carrier air group

The vessels are expected to be capable of carrying 40 aircraft, including 36 F-35 Lightning IIs as well as helicopters. In context, one carrier's air wing is almost three times the size of the Tornado GR.1 force deployed in Operation Desert Fox and the same number as the Tornado GR.4/Harrier GR.7 offensive fleet which participated in Operation Telic. Both of these land based deployments required the agreement of a local friendly nation. It was anticipated that the carriers would operate the Harrier GR9s until around 2018, as the RN will not have a complete F-35 group until then.

The Airborne Surveillance and Control (ASaC) component began as "Future Organic Airborne Early Warning" (FOAEW), with contracts being placed with BAE/Northrop Grumman and Thales in April 2001. In April 2002 BAE and Northrop Grumman received a follow-on study contract for Phase II of the project by then renamed Maritime Airborne Surveillance & Control (MASC).

The Lockheed Martin F-35 Lightning II is a family of single-seat, single-engine, fifth generation multirole fighters under development to perform ground attack, reconnaissance, and air defense missions with stealth capability. The F-35C carrier variant features larger wings with foldable wingtip sections, larger wing and tail control surfaces for improved low-speed control, stronger landing gear for the stresses of carrier arrested landings, a twin-wheel nose gear, and a stronger tailhook for use with carrier arrestor cables. The F-35 has been designed to have a low radar cross section primarily due to stealthy materials used in construction, including fiber mat.

The ships were originally intended to carry the Short Take Off Vertical Landing (STOVL) variant of the F-35 Lightning II, known as the F-35B. However, on 19 October 2010, David Cameron announced that the UK would change their order to the carrier variant (F-35C) and that the carrier design would be modified to use a catapult launch and arrestor recovery (CATOBAR) system to allow for the launch and recovery of these aircraft. The F-35C variant is cheaper and has a greater range and the ability to carry a larger and more diverse payload than the F-35B.The CATOBAR configuration will also enable the UK's defence partners such as the United States and France to operate aircraft from the carriers in joint mission situations.

An improved version of the Westland Super Lynx military helicopter, the Lynx Wildcat, entering service with the Royal Navy in 2015, will doubtless make up a significant number of the helicopters aboard both Queen Elizabeth Class Carriers. It will have room for seven passengers, a top speed of 187mph and a range of 520nmi. It will be armed with forward firing CRV7 rockets and machine guns, pintle mounted machine gun (eg FN MAG or Browning M2), Air-to-Surface Missile system: Thales Lightweight Multi-Role Missile (LMM), possibly Hellfire and Torpedoes and depth charges.

The Merlin is a medium-lift helicopter that performs a wide variety of functions for the Royal Navy. It performs exceptionally in an Anti-Submarine role. A chin FLIR is fitted to some variants. The AW101 (excluding the ASM MK1) is equipped with chaff and flare dispensers, directed infrared countermeasures (infrared jammers), ESM (electronic support measures, in the form of RF heads), and a laser detection and warning system. It has two hard points for weapon carriers, on which the HM Mk1 model can carry four Sting Ray torpedoes or Mk 11 Mod 3 depth charges, though at present cannot use the Sea Skua missile. The Mk1, Mk3 and 3a variants can mount General Purpose Machine Guns (GPMGs) in up to 5 locations in the main cabin pointing out of door and window apertures.

Royal Navy Merlins have seen action in the Caribbean, on counter-narcotics and hurricane support duties. They have also been active in Iraq, providing support to British and coalition troops on the ground, as well as maritime security duties in the North Persian Gulf.

Powerplant

The MoD decided not to use nuclear propulsion due to its high costs. The carrier's propulsion system will be integrated full electric propulsion (IFEP). Electric power is generated at 11,000 volts by two Rolls-Royce Marine Trent MT30 36 MW (48,000 hp) gas turbine generator units and four Wärtsilä Diesel Generator sets (two 9 MW (12,000 hp) and two 11 MW (15,000 hp) sets). This power is used for both the electric propulsion system and the ship's domestic system. The electric power is used to drive four, Converteam, Advanced Induction Motors, two per shaft and situated in three separate compartments to improve survivability in the event of action damage or flooding. Each 20 MW (27,000 hp) motor is driven by a Converteam VDM 25000 pulse width modulated converter which produces a variable frequency output allowing the shaft speed to be controlled across the full operating range. The propulsion power management system is integrated fully with the ship's platform management system provided by L-3 Communications. This unique propulsion system eliminates the need for large gearboxes, is compact and by minimizing the number of running generating sets for a given speed is very fuel efficient.

The design places one gas turbine generator unit under each island in the starboard sponson. This relatively high placement removes the requirement for air downtakes/exhausts deep into the ship. Conversely, the Diesel Generator sets are mounted low down in the ship, the weight of these units contributing to the stability of the ship. The unrefuelled range of the carrier will be 10,000 nmi (19,000 km).

The power and propulsion system is being designed and built in a Sub Alliance arrangement which brings together leading companies in their specific fields to provide the most cost effective mechanism for delivery of the integrated system for the QEC programme. This innovative arrangement is led by Thales UK as members of the Aircraft Carrier Alliance and partnered by Converteam UK, Rolls-Royce and L-3 Communications.

Systems

Many of the systems remain unspecified, but most of the designs that have been released so far show a BAE Systems Insyte/Thales S1850M long range radar on the forward island structure. However, it was announced on 4 August 2008 that they would also be fitted with BAE Systems Insyte Artisan 3D Radars as a medium range radar fitted to the aft island. Aster missiles may be installed for self-defence, but this has never been officially specified.


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