Duane Fotheringham, President of Mission Technologies’ Unmanned Systems business, HII

Interview: Duane Fotheringham, President of Mission Technologies’ Unmanned Systems business, HII

HII recently debuted the REMUS 620 Unmanned Underwater Vehicle (UUV). MTR caught up with Duane Fotheringham for furthers insights on the soft and hardware behind the new development.

By Greg Trauthwein

Image courtesy HII

Last month HII’s Mission Technologies division introduced a new medium-class unmanned underwater vehicle (UUV) dubbed REMUS 620 building on the legacy and the design philosophy of the REMUS 300, which was recently selected by the U.S. Navy as the program of record for the Lionfish Small UUV. Significant is the REMUS 620 has a battery life of up to 110 hours and a range of 275 nautical miles.

“The design approach for the energy system to be modular and dedicated to a single hull section was a key factor in enabling this improvement,” said Duane Fotheringham, president of Mission Technologies’ Unmanned Systems business group. “This allows additional energy sections to be added to the vehicle dependent upon mission needs and will facilitate alternative energy systems in the future.”

“Retaining a forward strategic advantage requires the ability to deliver a multitude of effects from under the sea,” said Fotheringham. “The REMUS 620 is the first medium UUV designed to accurately deliver this range of advanced above-and-below water effects at long range.”

According to Fotheringham, performance improvements were realized through a combination of factors, including: optimized mechanical packaging and structural designs which reduce piece part counts; optimized electrical architecture that reduces wiring; core electronics technology that facilitates dedicated energy modules, allowing us to engineer the maximum energy capacity/unit length ratio; incorporating the latest lithium-ion cell technology; and increasing main propulsion system efficiency.

Built to support current and next-generation naval and special operations forces operations, REMUS 620 features a modular, open architecture design to facilitate seamless payload integration and HII’s Odyssey suite of autonomy solutions for intelligent, robotic platforms.

REMUS 620 is the same size and weight of the first and only full-rate production medium UUVs: the MK 18 Mod 2, Littoral Battleship Sensing-Autonomous Undersea Vehicle (LBS-AUV) and LBS-Razorback systems operated by the U.S. Navy’s Mine Countermeasure Squadrons, U.S. Naval Oceanographic Office and Submarine Forces, respectively.

Multiple REMUS 620s operating collaboratively can be deployed from submarines, small manned or unmanned boats, amphibious ships, surface combatants and helicopters. REMUS 620 can also be used as a platform to launch and operate other unmanned vehicles or payloads from beneath the sea.

REMUS 620 is equipped with multiple batteries capable of 110 hours and a range of 275 nautical miles per mission. The energy modules are swappable, allowing for quick turnaround and incorporation of alternative energy sources as they become available.

The design approach for the energy system to be modular and dedicated to a single hull section was a key factor in enabling this improvement. This allows additional energy sections to be added to the vehicle dependent upon mission needs and will facilitate alternative energy systems in the future Duane Fotheringham,
president of Mission Technologies’
Unmanned Systems business group, HII

Clear Vision via SAS

REMUS 620 standard synthetic aperture sonar (SAS) payload can be replaced or enhanced for multi-mission capabilities, including intelligence, surveillance and reconnaissance, and cyber and electronic warfare operations. HII selected the Kraken Aquapix MINSAS-60 and MINSAS-120 as the standard imagery sonar options due to the Kraken’s combination of performance and versatility to suit a wide range of customer needs at a commercially competitive price, Fotheringham said. “This sensor provides high resolution interferometric Synthetic Aperture Sonar (SAS) and Bathymetry imagery along with optional real time data processing and Ultra High Definition (UHD) resolution.”

While special ops force operations are a key target, Fotheringham said commercial customers make up a key part of its customer base. “These customers are typically interested in environmental data collection, and/or acoustic and optical imagery, which the REMUS 620 supports,” said Fotheringham. “In addition to those applications, one of the key goals of the REMUS 620 is to allow any customer to explore new applications where a medium class UUV can be used to address evolving mission needs.”

With multiple geopolitical hotspots and the rapid rise in interest of seabed security, Fotheringham said that SAS “is rapidly becoming the sensor of choice for Mine Counter Measures due to its ability to maintain constant resolution over the entire swath.”

He said this allows more of the sonars footprint to be used where high resolution is required, such as Automatic Target Recognition, allowing the operators to make their track spacing wider which significantly increases Area Coverage Rate. Onboard real-time SAS processing provides the data required for an embedded ATR to identify contacts during the survey, allowing the vehicle to change its planning mid-mission to resurvey areas that require additional passes.

For seabed security, Fotheringham said “SAS provides the ability for AUVs to routinely survey critical subsea infrastructures such as channels, pipelines, and cables with very high-resolution data quickly enabling operators to identify any changes to the seafloor or new contacts which were not present during a previous survey.”

The SAS tech has value for the scientific community too, as with respect to environmental sensing, “it is an ideal tool for bottom type and habitat classification. Wide swaths allow for rapid surveys to delineate bottom types while increased resolution can actually identify areas that need to be protected such as critical nesting habitats and deepwater corals.”

In addition to this primary SAS payload, the REMUS 620 also offers a variety of different environmental sensor options which can be included in the vehicle configuration along with the SAS.

Control & Command

The Odyssey Mission Management software is an all-in-one UxV management suite in the form of an intuitive web-based user interface, said Fotheringham. “It allows an operator to plan, execute, monitor, and re-task the UxVs efficiently from a single console. Odyssey Mission Management uses an open architecture approach with well-defined Application Programming Interfaces (APIs), allowing a wide range of UxVs to be developed and deployed quickly.”

For example, the software allows the operator to plan a mission where a group of USVs and UUVs would collaboratively work to clear a water way. The operator could task the USVs to deploy the UUVs then begin conducting patrol of the area. Once deployed, the UUVs would be tasked to collaboratively search the waterway for hazards. During mission execution, the operator could re-task a single USV to rendezvous with a UUV for charging and data offload. Once the charging and data offload is complete, the USV and UUV would resume their original mission.

Ready for Residency

According to Fotheringham, HII has gained valuable experience working with REMUS 600 customers on subsea residency, such as the National Science Foundation Ocean Observatory Initiative (OOI) in which a REMUS 600 was designed for multiple months of sustained undersea operation.

“Some of the key considerations include ensuring the corrosion resistance features (primarily coatings and materials selection), energy charging, and data download capability support the mission requirements,” said Fotheringham. “The REMUS 620 provides a versatile platform that can be easily tailored to support a variety of missions, including ‘Subsea Residency.’ The increased endurance capability combined with a 12-hour charge time in the three energy module configuration provides a great foundation for this type of application to maximize vehicle operation while limiting recharge time.”


While much focus naturally is on the new vehicle, bigger picture these technologies are designed to seamlessly work in tandem, with the REMUS 620 capable of launching UAVs, too. “The specific launch sequence for deploying a UAV from a REMUS 620 will be dependent upon the UAV technology being used and any mission constraints,” said Fotheringham. “HII has demonstrated delivery of containerized UAV’s from the REMUS 600 platform in a submerged state although some UAVs may be better launched while the REMUS is at the surface.”

In addition to UAV payloads, the REMUS 620 can easily accommodate Intelligence, Surveillance and Reconnaissance (ISR) payloads and/or Electronic Warfare (EW) payloads which could be packaged in a wet or dry configuration as needed to best suit the payload technology. The limit of the REMUS 620 to carry and deliver payloads is only constrained by practical size, weight, and power constraints on this class of UUV. An optional hardware development kit will be available for REMUS 620 customers interested in developing unique payloads, including deployable or launched payloads.

December 2022