The Air Anti-Submarine Warfare Systems program office at the Naval Air Systems Command is evaluating the feasibility of using a compact rapid-attack weapon (CRAW), developed originally for ship torpedo defense, as an antisubmarine-warfare (ASW) weapon for the conventional-hull Freedom (LCS-1) and the trimaran Independence (LCS-2) variants of the littoral combat ship (LCS).
The Naval Sea Systems Command, Program Executive Office (PEO) for Littoral Combat Ships, and the Office of Naval Research (ONR), as well as industry officials have participated in the discussions.
The Navy’s larger surface combatants—Ticonderoga-class cruisers and Arleigh Burke–class destroyers—employ torpedoes and the vertical-launch antisubmarine (VLA) rocket for the ASW mission. The LCSs, however, have no capability to launch an ASW weapon from the ship’s deck.
PEO LCS is developing dedicated mission modules for surface, antisubmarine, and mine warfare that, when fielded, will be loaded and offloaded depending on the ship’s mission. The modules consist of the mission systems—weapons and sensors—and support equipment.
When integrated with the mission personnel and either the MH-60R (surface and ASW) or MH-60S (mine-warfare) helicopters, the modules are referred to as mission packages.
Module development, managed by systems integrator Northrop Grumman, is independent of the ship-construction program.
The modules will go through an extended series of testing and decision milestones on board both the Freedom and Independence variants. In April, the surface-warfare module successfully completed initial operational test and evaluation (IOT&E) on board the Freedom variant Fort Worth (LCS-3). The surface module is scheduled for IOT&E on board the trimaran Coronado (LCS-4) next year. The mine-warfare package has gone through developmental testing on board the Independence (LCS-2).
The ASW module, which has gone through several modifications and is farthest from delivery to the Navy, currently includes two MQ-8B Fire Scout vertical-takeoff unmanned aerial vehicles configured with an electro-optical/infrared sensor. Replacing the two MQ-8Bs with a single MQ-8C, which is a heavier Fire Scout but can employ ASW sensor capability, is being assessed. The ASW module also includes the MH-60R helicopter fitted with an airborne low-frequency sonar and armed with the Mk-54 lightweight torpedo.
However, Naval Air Systems Command officials now are exploring the potential for replacing the 600-pound Mk-54 with the 200-pound CRAW on the helicopter, and arming the MQ-8C version of the Fire Scout with one or possibly two CRAWs.
Analysis thus far indicates that while the lighter CRAW would have a shorter range than the Mk-54, the MH-60R, if armed with two CRAWs, could carry more fuel and thereby operate at greater range and endurance than if it carried a single Mk-54.
Replacing the Mk-54 with the lighter CRAW also would reduce the weight of the ASW mission package, which is strictly limited, and consequently would mean less total ship weight.
Because the helicopter cannot operate continuously, reliance on the Mk-54 as the sole ASW weapon would eliminate the LCS’s capability to engage a detected submarine when the helo is not available. The two Fire Scouts, armed with CRAWs, could be deployed in addition to the MH-60R, increasing the time that the LCS would have an ASW weapon airborne.
The CRAW, like the Mk-54, is equipped with a guidance-and-control system, including an active acoustic sensor for terminal guidance that enables it to home on a submarine target.
A shift to the CRAW, officials note, could result in reduced ASW capability. The Mk-54 detonation creates a powerful shock wave and a bubble that damages or destroys the submarine. The smaller CRAW is fitted with a shaped bolt charge that punches a hole in the submarine hull, generating less explosive power than the Mk-54 and requiring the weapon to strike the target at a specific angle for the charge to be effective.
The CRAW also is powered by a lithium battery that, without adequate safeguards, could pose a danger while stowed on board ship.
Pennsylvania State University’s Advanced Research Laboratory developed CRAW as part of a future naval capability funded by the ONR for the shipboard torpedo-defense mission; the weapon has been test-launched from a helicopter.
Naval Sea Systems Command’s Defensive Undersea Systems Program Office has studied CRAW as a potential torpedo-defense solution. However, CRAW is not a Navy program of record, and no funding has been approved to transition the system from ONR to production. A decision to pursue CRAW as an ASW solution for LCS also would require development of a concept of operations.