ACHILLES CLASS | AIRCRAFT CARRIER
Length: 349 meters
Width: 86.3 meters
Draft: 14 meters
Displacement: 114,674 tons
The Achilles class Nuclear powered Aircraft Carrier (CVN) was a program started by Belfrasian shipwrights in the 1980s to replace the ageing Carriers then in service with the Belfrasian Navy.
The first Achilles class Carrier was launched in 1996 after almost twelve years of designing and development. It remains the largest Carrier built and launched by the Belfrasian Navy and definitely one of the most powerful it's produced.
The first ship, the Aleksandr Achilles was proven to be a triumph in disguise. The unusually long design time meant that the majority of design faults had been corrected, bar one minor problem with the propeller shafts that was fixed in 2004. In 2007, eleven years after the Aleksandr Achilles' launch, the Carrier began mass production in the Belfrasian Navy.
The Achilles class CVN contains and perfects many traits of the old Nimitz class Aircraft Carriers. The bulbous nose has been refined and the stabilisation system redesigned entirely to include a two-piece rib system and two stabilisation fins. The aft of the vessel has been streamlined, bringing the propellers behind the main bulk of the ship so reduce its wake profile and sonar image and a redundant rudder amidships provides the ship with turning capability if the main rudder is knocked out.
Watertight compartments, insulation, routing, back-up control systems and a blast and fragmentation retaining superstructure provides a high level of survivability against missile attacks and fire hazards. An unintended benefit from the level of protection each compartment contains is that in the event of a chemical or biological attack the compartments can be made airtight with a limited life-span oxygen replenishment system to help improve survivability until rescue.
The hull has a dual layered composition with large heavy steel plates, measuring several inches thick as well as multiple layers of Kevlar that spans the majority of the hull and thickens around the base of the tower to protect the reactors and other vital components. The Achilles is also equipped with a double-bottom for added protection against both torpedoes or unintentional incidents. In the event of an Electro Magnetic Pulse (or EMP) the ships vital areas, namely the reactor and the CIC, are protected with electro-absorbing mesh woven into the walls and the adjoining doors. This, when tested, allows the ship to remain remotely functional after a strike and is able to power its CATOBAR systems to continue in a lessened combat role.
As part of its recent updates, the hull design has been slightly reinforced against ice and cold climates to allow operation in arctic conditions. It should be noted that the Achilles is without an icebreaking bow and needs an Icebreaker should it wade into frozen seas.
The majority of systems used aboard the Achilles is either modified from an existing system or designed for the sole purpose of being used aboard this Carrier.
The ship is equipped with a Belfrasian modified version of SEWACO (SEnsor, Weapon control And COmmand system) for use with its VLS cells and CIWS weapon systems to better allow them to work together in protecting the ship and proving the ability to route and assign targets to the necessary weapon system to limit the amount of input needed at the multi-function consoles on the Tower.
The tower has whats called an 'Integrated bridge and navigation system' installed, which consists of multi-function consoles capable of displaying functions such as Sensor references, electrical chart display and information systems (or ECDIS) as well as their designated purpose. Should a console be damaged, a neighbouring console can access that ones functions and preform them to a limited degree until a new console can be fitted. Each ship usually carries five to ten spare consoles that are assembled over the hardpoint.
The tower of the Achilles class is open designed, meaning the top deck with bow and aft viewing windows are essentially one large room. This integrated bridge is host to an integrated navigation system that encompasses the steering and control equipment ring-laser based Marine Inertial Navigation System (MINS), two data distribution units and a complete set of navigational sensors and meteorological equipment. This deck, and the decks below, are linked with a redundant Ethernet system that interconnects the multi-function consoles and sensors for internal use.
The communications system is coupled with a high capacity digital communications switchboard, which interconnects the voice and data communications channels. The system helps provide internal room-to-room communications or an open conference line for ship wide broadcasts. External communications accesses various radio or short-wave channels and land based networks. Standard external communications include Link 11, Link 16, Link 22, Joint Tactical Information Distribution System (JTIDS) and JSAT tactical data links, allowing interoperability with the fleet or any allied forces. In addition internet and intranet ports are available in each quarters and are available to closed-circuit consoles to ensure the onboard secure system isn't compromised by internet connection. The Achilles' default internet connection is rated at 20 mbps download. In extreme weather situations or in the event of damage the quality may reduce to 11 mbps for safety measures.
The majority of systems aboard the Achilles are 'open designed', meaning that they are programmed to run on the same operating system. This, along with the hard connections between all of the on-board systems means that duties from each console can be rerouted to a secondary console if the first is damaged or put out of action by other means. Managing all this are two consoles on the bridge. In addition to this, the data lines are shielded and armoured and have in-built rerouting drives if data lines are severed in battle. In the event that the Tower is destroyed, functions like engine control and CATOBAR systems can be rerouted directly to the engine room and the flightmasters booth on the port side of the flightdeck.
The Achilles is riddled with sensors, cameras, air and watertight doors and one of the most advanced damage control systems onboard a Belfrasian designed ship. The ADCS combines these to reduce response time in life and ship threatening events and reduce the number of crewmembers needed for an efficient damage control. Depending where the damage or what kind it is, the ships ADCS can deploy a foam spray to quell fires. The interior of the ship is remarkably modular with each compartment being self contained. These compartments can be manually or automatically sealed off from the rest of the ship or, if its below the waterline, flooded with seawater. This flooding action is intended to aid in fighting fires or in the event of an imminent explosion to dampen the blast by using the water to absorb the concussion effect and the water pressure reinforcing the walls against the explosion itself.
The Achilles' flight deck is large, more so then the Nimitz. This enables its five Catapults, three on the bow and two on the outboard side opposite the Island to be spaced out more and provide a larger area for aircraft manoeuvres or other duties aboard the flight deck to be carried out with little harassment. The flight deck also is host to an 'optional shunt' line along the reactors coolant vein. In arctic conditions, the optional shunt is activated and the hot coolant fluid passes underneath the flight deck. Both cooling the fluid down from the temperatures and warming up the flight deck. This, and standard anti-ice treatments, are available for combating ice in peacetime or wartime scenarios. It is, however, recommended that in a combat situation only anti-ice treatments are used as the risks that come from a ruptured coolant line if the ship is hit are far to great.
The Catapults aboard the Achilles are Electromagnetic Aircraft Launch Systems (EMALS) which were designed for use aboard the Gerald R. Ford class Supercarrier. The choice to use EMALS was based on several facts and advantages. EMALS controls a launch more accurately at greatly velocities without excess weight or construction room needed to generate the steam. A standard steam-based Catapult system requires some 614kg of steam to achieve 95 Megajoules in a launch, whereas the EMALs system doesn't require the steam and achieves a vastly superior 122 Megajoules in a launch. EMALs, in addition, requires less maintenance and manpower and takes up less room and weight then the standard Steam Catapults.
The three catapults on the bow of the Achilles are arranged similar to the Nimitz, but with more space between the two and a third that runs down the length between them from slightly further back. This means that three fighters can be attached to their catapults but the first at the rear cannot launch before the first two. The two on the outboard part of the flightdeck are arranged similar to that on a Nimitz, with the furthest one having the second cross in front of it, meaning that they cannot launch simultaneously.
Operations below in the Hanger deck are simplified, a machine shop at the rear of the deck provides repair capabilities to engines or other small parts and a secure ordnance area sits below the Hanger deck with a small service elevator to bring them up onto the Hanger deck. Aviation fuel is stored in tanks at the centre of the ship and are pumped up to the Hanger deck in eight positions for refuelling or defuelling planes.
Propulsion for the Achilles consists of two KE-4 Nuclear reactors and four steam turbines, one to each of the vessels four propellers. Each shaft is capable of generating 65,039 horsepower, resulting in a combined 260,158.285 horsepower between the four turbines to give the ship a speed of 31.4 knots
The two KE-4 reactors sit in a two-reactor complex to reduce size. They differ from their Nimitz cousins in that they're a smaller, more efficient design then the Nimitz AW-4 which could only produce 104mw each. The KE-4, which sits in a two-reactor complex, generates just over 312 megawatts each to result in a 623mw output to generate both the 194mw needed to propell the shafts and the power to run ship-based systems. Controls for both the reactor and the engine can be accessed from the Engine room or the Island using the multi function controls and a passcode.
The Achilles' four propellers are assisted by a main rudder and a redundant rudder. The main rudder, which is fixed between the four, operates as a rudder normally would. If the main rudder is taken out or disabled the smaller rudder activates in its place. While turning is greatly reduced, the vessel is still able to maintain some form of control. The houses of the Propellers and the rudders are shielded as to prevent ice blockages if operating in arctic conditions. The natural position of the propulsion system also helps to protect it from ice formations under the water as its streamlined with the main ships body.
The Achilles makes use of the AN/SPY-3 radar system for multiple functions, such as horizon search and precision tracking for searching and destroying enemy aircraft. Other then that, it utilises the Mk. 2 Type 7087 Air Search Radar for airspace control, and a modified version of the AN/SPQ-9B for target acquisition for both the SSM ordnance and to help guide CIWS mounted AA missiles toward their target. The Achilles uses the AN/SPN-45 to aid aircraft in landing with AN/SPN-41, SPN-43C and SPN-46 for air traffic control and landing aid.
Search radars aboard the Achilles encompasses the AN/SPS-49(V)5 and AN/SPS-48E, which is a 2-D and 3-d air search radar respectively. Guidance or simple horizon-search radar involves Mk. 105 radars, a modified version of the Mk. 95 seen on the Nimitz and the Mk. 91 NSSM Guidance system for the AA ordnance in the vertical launchers.
The Achilles class carrier is different to the Nimitz in that it possesses a potent surface attack capability outside that of its air group. The Achilles has a Vertical Launch System (VLS) complex built on the Island with 24 aft of the Island and 32 forward of the Island for a total capable deployment of 56 missiles including the Tomahawk, ESSM, the RIM-161 or other missile system capable of fitting inside the VLS cells. Missile reloading of light ordnance like the Tomahawk can be done at sea from the vessels magazine although heavier ordnance reloading would require a munitions ship or the carrier to be docked. The use of vertical-launch modified ASROCs was also intended to provide the Carrier with some light ASW capabilities, although the UDAV-1 system would be primarily used with defeating incoming ordnance.
Defence against underwater attack comes in the form of the Udav-1 anti-submarine system. Each Achilles is equipped with two aft-mounted Udav-1s on both port and starboard sides of the vessel. The rocket system is theoretically capable of attacking nearby submarines but is intended to provide a multi layer defense against torpedoes and frogmen. Each system has a total of 60 missiles inc. reloads, resulting in 120 anti-submarine and torpedo kill weapons onboard each Achilles.
The system consists of an ammunition loading device, fire controls and ground support equipment for crew manning each of the weapon systems. In addition, hardlinks between the launchers and the Island exist so they can be operated from the safety of the control deck and the control station at the Udav itself. Aside from that, the Udav-1 consists of the following;