Eight Legend Class National Security Cutters (NSCs) are being built under the Deepwater Programme of the US Coast Guard (USCG). Built by Northrop Grumman Ship Systems, NSC is the largest and most technically advanced class of cutter in the USCG fleet. The NSCs will replace the aging 378' High Endurance Hamilton class cutters in service since the 1960s.
NSCs can be deployed in homeland security, law enforcement, maritime safety, environmental protection and national defence missions.
Legend Class cutter programme
In June 2002, the USCG signed a $17bn contract with Integrated Coast Guard Systems (ICGS, a joint venture of Northrop Grumman and Lockheed Martin) for the Deepwater Programme. The programme includes delivery of 91 (eight NSC, 25 OPC and 58 FRC) new cutters, 35 fixed-wing aircraft, 34 helicopters, 76 UAVs, 93 upgraded helicopters and 49 upgraded cutters over a 20 year schedule.
In July 2005, the programme was expanded to 25 years due to post-9/11 mission requirements. As a result, the contract value increased to $25bn.
Construction
Construction began in September 2004 and keel for the lead ship in class, USCGC Bertholf (WMSL 750), was laid at Ingalls Shipyard in March 2005. The ship was launched in September 2006 and commissioned in August 2008.
"The NSC-type is the largest combat ship in the USCG fleet."
The second NSC, Waesche (WMSL 751), was laid down in September 2006, launched in July 2008 and commissioned in May 2010.
USCGC Stratton (WMSL-752), was laid down in July 2009, delivered in September 2011 and commissioned in March 2012.
USCGC Hamilton (WMSL 753) was laid down in September 2012 and launched in August 2013. The ship is expected to be delivered in the fourth quarter of 2014. The fifth ship in class, Joshua James (WMSL 754), is also under construction for the delivery in the second quarter of 2015.
Construction of the sixth vessel, NSC Munro (WMSL 755), began in October 2013. A long-lead material contract was placed in June 2013 for the seventh NSC.
National Security Cutter design
The NSC-type is the largest combat ship in the USCG fleet. After reviewing the NSC design during 2002-2004, the USCG raised questions about the ship structure that could preclude the service life of the cutter. Consequently, engineering changes were implemented and structural components were enhanced in collaboration with the US Navy and naval engineering experts to achieve the desired 30-year service life.
NSC has an overall length of 127.4m, a beam of 16.4m and a draft of 6.8m. The full load displacement is 4,400t. The ship can accommodate a crew of 110.
Features
Designed to deliver better sea keeping capabilities, the NSC is equipped with facilities to launch and recover improved small boats, helicopters and unmanned aerial vehicles at higher sea states. The cutter has a higher sustained transit speed than current vessels, along with a greater endurance and range.
"In June 2002, the USCG signed a $17bn contract with Integrated Coast Guard Systems."
The onboard C4 intelligence, survival and reconnaissance (ISR) system provides real-time situational awareness and enhances interoperability between naval units. The cutters feature NBC detection and defence systems to repel chemical, biological or radiological attacks.
Two cutter boats (a long range interceptor and/or a short range prosecutor) can be stored in the aft launch and recovery area.
Armament
The main gun fitted forward is an MK110 57mm gun. It can fire at a rate of up to 220 rounds per minute for a range of nine miles. Close-in air defence capability is provided with a 20mm Close-In Weapon System (CIWS).
Sensors / radars
The NSC is equipped with X&S band surface search radar, EADS 3D air search radar, SPQ-9B fire control radar and Mk46 electro-optical / infrared sensor.
Aircraft
The 50ft x 80ft flight deck can support the operations of a range of manned and unmanned rotary wing aircraft. It can accommodate an MH-65C or MH-60T and two vertical launch unmanned aerial vehicles, or other combinations. It is also provided with a hangar for aircraft storage.
Countermeasures
The SLQ-32 electronic warfare system protects the cutters from anti-ship missiles in an open sea environment. The MK 53 NULKA anti-ship missile self defence system integrates decoys / launchers, a decoy launch processor (DLP) and processor power supply (PPS). It can deceive new generation radar homing anti-ship missiles by launching autonomous decoys.
Propulsion
The NSC is powered by a combined diesel and gas turbine (CODAG) propulsion system integrating a GE LM2500 gas turbine and two MTU 20V1163 diesel engines.
Two diesel engines and a gas turbine deliver a total power output of 49,875shp to the ship. The propulsion system provides a top speed of 28kt, a range of 12,000nm and an endurance of 60 days.