The Independence class is a class of littoral combat ships built for the United States Navy.
The hull design evolved from a project at Austal to design a 40 knot cruise ship. That hull design evolved into the high-speed trimaran ferry Benchijigua Express and the Independence class was then proposed by General Dynamics and Austal as a contender for USN plans to build a fleet of small, multipurpose warships to operate in the littoral zone. Two ships were approved, to compete with Lockheed Martin's Freedom class design for a construction contract of up to 55 vessels.
As of 2010, the lead ship is active, while a second ship, Coronado, is under construction. Despite initial plans to only accept one of the Independence and Freedom classes, the USN has requested that Congress order ten additional ships of each class, for a total 12 ships per class. In February 2012, Secretary of the Navy Ray Mabus announced that the fifth Independence-class littoral combat ship will be named USS Gabrielle Giffords, and the sixth USS Omaha.The Independence class design began life at Austal as a platform for a high speed cruise ship. The principal requirements of that project were speed, stability and passenger comfort and Austal's team determined that the trimaran hull form offered significant passenger comfort and stability advantages over both a catamaran and a monohull. The high speed cruise ship project evolved into Austal's commercial high-speed trimaran ferry Benchijigua Express. The ships are 127.4 m (418 ft) long, with a beam of 31.6 m (104 ft), and a draft of 13 ft (3.96 m). Their displacement is rated at 2,176 tons light, 2,784 tons full, and 608 tons deadweight.
The standard ship's company is 40-strong, although this can increase depending on the ship's role with mission-specific personnel. The habitability area is located under the bridge where bunks for ships personnel are situated. The helm is controlled by joysticks instead of traditional steering wheels.
Although the trimaran hull increases the total surface area, it is still able to reach sustainable speeds of about 50 knots (93 km/h; 58 mph), with a range of 10,000 nautical miles (19,000 km; 12,000 mi). Austal claims that the design will use a third less fuel than the competing Freedom-class, but the Congressional Budget Office found that fuel would account for 18 percent or less of the total lifetime cost of Freedom.
Modular mission capability
The Independence class carries a default armament for self-defense, and command and control. However unlike traditional fighting ships with fixed armament such as guns and missiles, tailored mission modules can be configured for one mission package at a time. Modules may consist of manned aircraft, unmanned vehicles, off-board sensors, or mission-manning detachments.
The interior volume and payload is greater than some destroyers and is sufficient to serve as a high-speed transport and maneuver platform. The mission bay is 15,200 square feet (1,410 m2), and takes up most of the deck below the hangar and flight deck. With 11,000 cubic metres (390,000 cu ft) of payload volume, it was designed with enough payload and volume to carry out one mission with a separate mission module in reserve, allowing the ship to do multiple missions without having to be refitted.
One Mobicon Flexible Container Handling System is carried on each ship in order to move mission containers.
In addition to cargo or container-sized mission modules, the bay can carry four lanes of multiple Strykers, armored Humvees, and their associated troops. An elevator allows air transport of packages the size of a 20-foot-long (6.1 m) shipping container that can be moved into the mission bay while at sea. A side access ramp allows for vehicle roll-on/roll-off loading to a dock and allows the ship to transport the Expeditionary Fighting Vehicle.
Armament and sensors
The Raytheon SeaRAM missile defense system is installed on the hangar roof. The SeaRAM combines the sensors of the Phalanx 1B close-in weapon system with an 11-missile launcher for the Rolling Airframe Missile (RAM), creating an autonomous system.
The Independence class ships also has an integrated LOS Mast, Sea Giraffe 3D Radar and SeaStar Safire FLIR. Northrop Grumman has demonstrated sensor fusion of on and off-board systems in the Integrated Combat Management System (ICMS) used on the LCS. Side and forward surfaces are angled for reduced radar profile. In addition, H-60 series helicopters provide airlift, rescue, anti-submarine, radar picket and anti-ship capabilities with torpedoes and missiles.
The flight deck, 1,030 m2 (11,100 sq ft), can support the operation of two SH-60 Seahawk helicopters, multiple unmanned aerial vehicles, or one CH-53 Sea Stallion helicopter. The trimaran hull will allow flight operations up to sea state 5. The Fleet-class USV is designed for opertions from Independence class ships.
The vessels have an Interior Communications Center that can be curtained off from the rest of bridge instead of the heavily protected Combat Information Center found on Navy warships.
Control system
The control system for this class is provided by General Dynamics, while Lockheed provides their own control system for their variant of the LCS.
Corrosion management
After the lead ship of the class has suffered from aggressive disintegration at the molecular level, Austal has made changes to the remaining ships in the class. Coronado will have "new anti-corrosion surface treatments", and Jackson will have "an array of tested corrosion-management tools and processes".| General characteristics | |
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| Type: | Littoral combat ship |
| Displacement: | 2,176 tons light, 2,784 tons full, 608 tons deadweight |
| Length: | 127.4 m (418 ft) |
| Beam: | 31.6 m (104 ft) |
| Draft: | 13 ft (3.96 m) |
| Propulsion: | 2× MTU Friedrichshafen 20V 8000 Series diesel engines, 2x General Electric LM2500 gas turbines, 2x American VULKAN light weight multiple-section carbon fiber propulsion shaftlines, 4x Wärtsilä waterjets, retractable bow-mounted azimuth thruster, 4× diesel generators |
| Speed: | 44 knots (51 mph; 81 km/h) |
| Range: | 4,300 nm at 18 knots |
| Capacity: | 210 metric tons (206 long tons, 231 short tons) |
| Complement: | 40 core crew (8 officers, 32 enlisted) plus up to 35 mission crew |
| Sensors and processing systems: |
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| Electronic warfare and decoys: |
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| Armament: |
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