Freedom-class littoral combat ship


The Freedom class is one of two classes of the littoral combat ship program, built for the United States Navy.
The Freedom class was proposed by a consortium formed by Lockheed Martin as "prime contractor" and by Fincantieri through the subsidiary Marinette Marine as a contender for a fleet of small, multipurpose warships to operate in the littoral zone. Two ships were approved, to compete with the design offered by General Dynamics and Austal for a construction contract of up to fifty-five vessels.
Despite plans in 2004 to only accept two each of the Freedom and Independence variants, in December 2010 the U.S. Navy announced plans to order up to ten additional ships of each class, for a total of twelve ships per class.
In early September 2016, the U.S. Navy announced that the first four vessels of the LCS program, the Freedom class ships Freedom and Fort Worth and two Independence class, would be used as test ships and would not be deployed with the fleet. In February 2020, the Navy announced that it plans to retire those same four ships. On 20 June 2020, the US Navy announced that all four would be taken out of commission in March 2021 and placed in inactive reserve.

Planning and construction

Planning for a class of small, multipurpose warships to operate in the littoral zone began in the early 2000s. The construction contract was awarded to Lockheed Martin's LCS team in May 2004 for two vessels. These would then be compared to two ships built by Austal USA to determine which design would be taken up by the Navy for a production run of up to fifty-five ships.
On 15 April 2003, the Lockheed Martin LCS team unveiled their Sea Blade concept based on the hull form of the motor yacht Destriero.
The keel of the lead ship was laid down in June 2005, by Marinette Marine in Marinette, Wisconsin. She was christened in September 2006, delivered to the Navy in September 2008, and commissioned that November. During INSURV trials, 2,600 discrepancies were discovered, including 21 considered high-priority. Not all of these were rectified before the ship entered service, as moving the ship away from Milwaukee before the winter freeze was considered a higher priority.
Cost overruns during Freedoms construction combined with projected future overruns led the government to issue a "stop-work" in January 2007 and ultimately led to the cancellation of construction of LCS-3 on 13 April 2007. This ship was later reordered.
After much inconsistency on how testing and orders were to proceed, in November 2010, the Navy asked that Congress approve 10 each of the Freedom and Independence variants.

Design

The ship is a semiplaning steel monohull with an aluminum superstructure. It is in length, displaces, and can achieve. The design incorporates a large, reconfigurable seaframe to allow rapidly interchangeable mission modules, a flight deck with integrated helicopter launch, recovery and handling system, and the capability to launch and recover boats from both the stern and side.
The ship uses a Trigon traversing system to move helicopters in and out of the hangar. The ship has two ways to launch and recover various mission packages: a stern ramp and a starboard side door near the waterline. The mission module bay has a three-axis crane for positioning modules or cargo.
The most serious problems with the Freedom class have been with the electrical systems.
The fore deck has a modular weapons zone which can be used for a 57 mm gun turret or missile launcher. A Rolling Airframe Missile launcher is mounted above the hangar for short-range defense against aircraft and cruise missiles, and.50-caliber gun mounts are provided topside. The is designed for operations from Freedom-variant ships.
The core crew is 40 sailors, usually joined by a mission package crew and an aviation detachment for a total crew around 75. Automation allows a reduced crew, which greatly reduces operating costs, but workload can still be "gruelling". During testing of the class lead, two ship's companies rotated on four-month assignments.
Four 750-kilowatt Fincantieri Isotta Fraschini diesel generators provide 3 megawatts of electrical power to power the ship systems.
The Congressional Budget Office estimated that fuel would account for only "8 percent to 18 percent" of the total lifecycle costs for the Freedom class. Senator Jeff Sessions of Alabama called the report into question and suggested that the Independence class, built in his state, would be more fuel efficient and that less frequent refuelings would affect military operations beyond the cost of fuel.
In 2012, a Navy cybersecurity team found major deficiencies in Lockheed's Total Ship Computing Environment, which controls the entire ship to reduce crewing requirements.
Survivability has been a criticism of both the Freedom and Independence classes, rated at level one by the Navy, compared to level two for the guided-missile frigates they were designed to replace. Lockheed claims the Freedom class is actually more survivable than the FFGs because Navy requirements for various survivability levels have changed since the FFGs were assessed, and because the Freedom class hulls are made of high-strength, low-weight steel that was not previously available.
was the first Freedom-class ship to be fitted with cavitation performance waterjets. The jets create partial vacuums in liquid using an improved impeller blade design. Cavitation jets do not increase the ship's top speed, but deliver 10% greater fuel efficiency with less noise and vibration, reduced lifecycle costs, improved maintainability, increased availability, and potentially improved efficiency at lower speeds. In 2014, the Navy announced plans to add these waterjets to every Freedom variant that is produced. The mixed-flow design was changed to an axial design to push water parallel to the shaft of the impeller.
The first ships of both LCS classes were delivered before the designs were mature so that improvements could be built into future ships. Many improvements to the Freedom class came from the problems experienced by Freedom on the ship's first deployment, including power outages, corroded equipment, and a faulty air compressor. To prevent water from being taken into the anchor windlass room, the anchor winch, hydraulic unit, and mooring capstan were replaced with a single electric chain winch on the main deck, and the existing towing chain was replaced with a lighter chain.
Corrosion resistance was also improved by the impressed-current cathodic protection system being modified by adding protections to the water-jet inlet tunnel. Adjustments to the Freedom class, starting with LCS-3, saw the stern transom lengthened and buoyancy tanks added to the stern to increase weight service and enhance stability. Plans were adjusted to see a significantly less complex gas-turbine electric start system added on LCS-5 to reduce costs and lower ship weight.
Starting with LCS-17, the Freedom-class ships will be equipped with the TRS-4D naval radar. The TRS-4D is an AESA radar built by Airbus Defence and Space that is similar to the one on German s, the difference being the Freedom class will have a rotating version instead of a fixed panel, the first AESA rotating radar aboard a U.S. Navy ship. It is a three-dimensional, multifunction naval radar combining mechanical and electronic azimuth scanning that delivers increased sensitivity to detect smaller targets with greater accuracy and faster track generation.

Engine maintenance incidents

, three of four active Freedom-class ships had suffered maintenance incidents involving the engines and/or associated propulsion hardware. Milwaukee broke down in the Atlantic Ocean in December 2015 and had to be towed back to port. Metallic debris was found in the filter system. The cause was traced to a clutch between the gas turbine and diesel engine systems, which failed to disengage as designed while switching from one propulsion system to the other.
Fort Worth suffered a similar breakdown in the Pacific Ocean in January 2016. Improper procedures used aboard ship caused a set of combining gearshardware used to transfer power to the ship's water propulsion systemto be operated with insufficient oil. And in July 2016, Freedom suffered a seawater leak into one of her two main diesel propulsion systems and had to return to San Diego for seawater decontamination.

Transmission design defect

The Freedom class has experienced severe issues with its transmission, specifically, its combining gear, a system described as "generally unreliable", yet one that needs to be engaged for reaching the speeds over. After Little Rock suffered a breakdown of its combining gear early in 2020, Detroit had to limp back to port in Mayport, Florida in October 2020 from a deployment to South America after suffering another breakage of the combining gear.
In January 2021, the Navy halted deliveries of Freedom-class ships due to a design flaw of the ship's combining gear. The Navy, Marinette and the firm that designed the combining gear, Renk AG, were working on an upgrade to address the issue. The Navy announced that, once the upgrade is complete, new deliveries will resume. The Navy predicted it would take months to implement the upgrade to ships already in active service. Commissioning of LCS-21, Minneapolis-St. Paul was thus postponed.
The combining gear problem was later fixed and applied to LCS-19 St. Louis and all follow-on ships. LCS-11, 13, 15 and 17 have all begun undergoing repair work or are scheduled to do so. The cost for fixing the defective combining gear is estimated to be between $8 million and $10 million per ship.