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Video Above: Columbia-class Submarine 

By Kris Osborn - President & Editor-In-Chief, Warrior Maven

Helicopters, drones, destroyers and submarines will soon be armed with a new, high-speed, explosive Very Lightweight Torpedo weapon designed to destroy enemy submarines, ships and other targets of interest.

The new weapon, slated to enter production within the next several years, represents a series of collaborative efforts between U.S. Navy weapons developers, academic researchers at Penn State University and industry partners from Northrop Grumman. 

Existing heavyweight torpedoes have been receiving numerous electronics, explosives and guidance systems in recent years through a series of upgrades, yet this Navy Very Lightweight Torpedo effort is the first Torpedo solicitation the Navy has put out since the 1980s.

Very Lightweight Torpedo 

“We have a prototype. We learned a lot by building that prototype and then consulting with the Navy with where we saw the risks and the opportunity. We are also working on reducing the cost overall by trying to cut 50-percent of the current cost of some subcomponents,” David Portner, Senior Northrop Grumman program manager, told Warrior in an interview.

Very Lightweight Torpedo

Very Lightweight Torpedo

The Very Lightweight Torpedo program emerged from a previous effort to engineer and test a first-of-its-kind Torpedo defense system designed to track, intercept and destroy attacking enemy torpedoes. Interestingly, Northrop engineers adjusted the software to enable an offensive capability for the weapon, which still retains the ability to be programmed for Torpedo defense as well.

“It is a software-enabled hardware which has not lost its anti-torpedo software system so it could easily fill both roles,” Portner explained.

Given the smaller, more compact size of a weapon that is 6ft in diameter and 9ft long, the VLTs are designed to fit into the 6-inch countermeasure launchers on current submarines. 

They are not launched out of normal 21-inch tubes. Interestingly, the weapons can be launched by surface ships from 12 and ½-inch torpedo tubes on cruisers and destroyers and even fired from drones and helicopters. The smaller form factor for the torpedo opens up a range of new tactical possibilities for torpedo attack as it can fire from more platforms and be carried in larger numbers. The larger Mk 54 torpedo is simply too large and too heavy for many of these applications.

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MK-54 Torpedo

MK-54 torpedo being launched from an Arleigh Burke-class destroyer (photo courtesy U.S. Navy)

“The weapon has been demonstrated to be dropped from air and opens up the anti-submarine platforms. Submarines would be the initial platforms for the weapon, yet once it demonstrates its effectiveness the Navy will employ it on all the other platforms it can use it on,” Portner said.
As a smaller, 6ft-by-9ft torpedo, the Very Lightweight Torpedo introduces a new sphere of tactical applications and launch points for Navy commanders to consider, as they can be carried in larger numbers, dropped from the air, fired from small submarine launch tubes or even by forward operating undersea drones. Work on the weapon has involved Navy, academic and industry partner collaboration for many years now. Northrop Grumman has built prototoypes.

“The actual size is designed to fit into the 6-inch countermeasure launchers on current submarines, and not launched out of normal 21 inch tubes,” David Portner, Senior Northrop Grumman program manager, told Warrior in an interview. 
While many of the guidance and energetics or warhead specifics are not likely available for security reasons, however broadly speaking it is likely the weapon is engineered to attack sophisticated maneuvering targets equipped with torpedo countermeasures. 

Northrop Grumman Very Lightweight Torpedo

Northrop Grumman Very Lightweight Torpedo (VLWT)

The scope of this challenge is explained in an interesting essay by Korea Science titled “Effectiveness Analysis for a Lightweight Torpedo Considering Evasive Maneuvering and TACM of a Target.” The abstract for the paper outlines the scope of advanced threats as it pertains to essentially countering or overcoming “countermeasures” employed by advanced submarines. TACM, which stands for Torpedo Acoustic Counter Measure is described in the abstract as consisting of “floating-type decoys, self-propelled decoys and jammers.” Along with simple “evasive maneuvering,” advanced submarines likely employ these kinds of countermeasures.

This means that academic, Navy and Northrop Grumman developers of VLT guidance technology have likely been focused on engineering targeting technologies and sensors able to “discriminate” actual submarines from decoys. Guidance systems and undersea torpedo trajectory are also likely to be “hardened” against jamming and other kinds of intrusions and interference to enable them to achieve a complete “hit” on a target. Surface ships also have “jammers” and various kinds of defenses the VLT would need to be engineered to overcome.

Development of the weapon has been a collaborative process between Northrop Grumman’s efforts to leverage its own internal research and development funds and while seeking guidance and input from Navy engineers and weapons experts about requirements and desired performance parameters. Portner said Northrop Grumman built its prototype based upon drawings from the Navy in 2017, and has continued dialogue with the service to recommend adjustments and respond to emerging Navy requirements.

“We’ve been investing in this since 2013. About 2018 the Navy sent out a design documentation for industry to evaluate. We used that to build a risk reduction prototype to basically determine what the supply base health is and where there might be challenges to production.”

Successful construction of the weapon will require extensive and well coordinated integration of different technological spheres to include warhead design, propulsion, guidance technology and energetics or explosive characteristics of the weapon.
“It is a smaller warhead with different functional capability than your standard bulk charge warhead. We are developing a cross-country and cross-sector solution which brings in the expertise to address transitioning this to production. Our Defense System has expertise in warhead production and warhead design. 

Our Mission Systems has expertise in warhead production and warhead design and the capability for electronics. Our air systems sector would be focused on integration with Fire Scout and air platforms once it reaches that level,” Portner explained.
Following plans to release a formal Request for Production (RFP), the Navy is expected to select a contractor in early 2022 and then award a three-year deal to transition into Low Rate Initial Production.

 Kris Osborn is the defense editor for the National Interest. Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Master’s Degree in Comparative Literature from Columbia University.

Kris Osborn, Warrior Maven President

Kris Osborn, Warrior Maven President