The Navy is weeks away from announcing the final design for two reduced-weight sonar systems that the Littoral Combat Ship (LCS) will deploy to hunt submarines, the service’s program manager told Defense Daily in a Jan. 29 interview.

The service in 2015 awarded contracts to Raytheon [RTN], Advanced Acoustic Concepts and L-3 Communications [LLL] to drive down the weight of two core systems from the LCS’ anti-submarine warfare (ASW) mission module—the variable depth sonar and a passive multifunction towed array sonar—to 105 metric tons. The companies have submitted their weight-reduction proposals, and the Navy is “very close” to exercising one or multiple contract options for the final design, said Capt. Casey Moton, the service’s program manager for the LCS mission modules.

The Littoral Combat Ship USS Freedom (LCS-1). Photo: U.S. Navy
The Littoral Combat Ship USS Freedom (LCS-1). Photo: U.S. Navy

“We’re probably very near exercising that contract option, and then we’ll then move forward with that weight reduction,” he said. “We’re getting ready to go talk to Pentagon leadership to get approval. So I hope it’s anywhere from a few weeks to a month.”

Once contracts are awarded, the ASW module will move into its engineering and manufacturing development (EMD) phase. Industry is slated to deliver the EDM-version of the ASW mission module in 2017.

The award will have implications not only for the LCS—which was designed as a modular vessel that would be outfitted with various mission packages allowing it to fight surface ships, destroy mines, or hunt submarines—but for the multi-mission frigate version of the LCS. Under the current program of record, all 20 frigates will be permanently equipped with the sonars. The Navy is still in the process of determining how many ASW packages it will buy, leaving its total purchase of the variable depth sonar (VDS) and towed array sonar still up in the air.

“It’s a big decision,” Moton said.

The Navy plans to award contract options for reduced-weight handling systems that will be used to launch, recover and tow the VDS and towed array sonar. Some of the modifications proposed by the contractors include changes to the cable winch or hydraulic system that would decrease size and weight or increase commonality, he said. Companies also looked at the possibility of moving from hydraulic to electric systems, which are lighter.  

In addition to the handling systems, the service will award a contract option for the variable depth sonar, Moton said. The towed array sonar sensor will be furnished by the government.

The VDS in particular will offer the service a significant step-up in detection capability because, as a continuous active sonar, it constantly sends out sound, making it easier to track the movements of enemy submarines based on the echoes it receives.

Another benefit is that it can be dropped under the “thermocline layer,” an area where subs can evade detection because the abrupt change in water temperature helps to obscure soundwaves. “That’s a big advantage that our current combatants don’t have,” he said.

Throughout the interview, Moton stressed that the Navy was only interested in mature technologies for the VDS and the handling systems. Contractors were required to have a pre-existing VDS and had to prove “that they had a level of maturity, that there had been some testing already done.”

The LCS program office also employed a new contracting method called Rapid Technology Insertion, which sped up the acquisition process by standardizing much of the contracting paperwork, Moton said.

“It takes a lot of work and a lot of documentation to prepare a contract package,” he said. “The clauses, the way the contract items are structured, all of these details that you have to do for a company to bid, that was all standard [in RTI]. We basically are able to come in with a very tailored technical document…and then all the rest of that stuff that usually takes a while to take while, that contracting piece, it’s already done.”

While the service is making headway in developing the EDM version of the ASW mission module, it suffered a setback late last year when Congress cut funding that would have allowed it to test an earlier version of the package known as the Advanced Development Model (ADM). The Navy in 2016 planned to conduct a second at-sea test of the ADM package, which consists of full weight VDS and towed array sonar.

The service first demonstrated the ADM off the coast of California in 2014, during tests aboard the USS Freedom (LCS-1) that the Pentagon’s director of operational test and evaluation (DOT&E) criticized as being highly scripted. “It was highly scripted,” Moton said, but “even their reports say that is appropriate for this stage of testing, and we were able to exhibit detection of submarines at these very high ranges.”

A second round of demonstrations off the coast of Hawaii would have permitted the Navy to test the systems in a different operating environment and against a more realistic set of targets, he said. It would have also provided another opportunity for the crew to practice using the sonars.

“Did I want to do all those things? Yes,” he said. “We won’t be able to do that, but we are going to figure out how to overcome that. It does not set the program back on schedule.”

The Navy plans to proceed with some testing of the ASW package this year. It will demonstrate modifications to the Freedom-variant’s doors that allow it to deploy the sonar at high speeds. Further land-based tests of the ADM are also under consideration, although they would be more limited in scale, he said.