VESSEL REVIEW | UUV trio to expand UK Royal Navy’s minehunting force

US-based defence and technology company Huntington Ingalls Industries (HII) has delivered three unmanned underwater vehicles (UUVs) in a series to the UK Royal Navy for use in mine countermeasures (MCM) missions.

The compact UUVs are the latest examples of a series that HII first supplied to the Royal Navy in 2002. HII said the first two UUVs are still in UK service today.

Each craft has a length of 1.85 metres, a hull diameter of 0.19 metres, and a displacement of 38.6 kilograms. The UUVs were designed as low-logistics craft that can be rapidly deployed from any vessel of opportunity. Each is rated to operate at a depth of 100 metres and can be carried, deployed into, and recovered from the water by two personnel, thus eliminating the need for dedicated launch and recovery systems (LARS).

The craft are capable of operating for up to 10 hours or 67 kilometres at speeds of 4.5 knots thanks to a rechargeable 1.5kWh lithium-ion battery driving a DC brushless motor containing an open three-bladed propeller. A cruciform fin control assembly is manipulated to determine each UUV’s yaw and pitch. The battery can be fully charged in six hours.

MCM missions can be carried out in port and shallow waters as well as in the open ocean. Using a Marine Sonics 900/1800kHz dual frequency side scan sonar with a 160-metre swath, each UUV can survey large areas autonomously to allow human operators to review data away from a minefield to identify and classify mine-like objects with greater safety.

All data gathered by the UUV are stored in a 1TB solid state hard drive. High-quality data acquisition is possible as the sonar can capture clear images even of objects that are only five centimetres wide, hence enabling Royal Navy operators to more easily identify potential mines for avoidance or disposal.

Even with their small size, the UUVs can accommodate various other electronics such as a Garmin GPS, an iXblue inertial navigation system, a Teledyne 300kHz phased array Doppler velocity log, Iridium communications equipment, and conductivity and temperature sensors. Safety features include a leak detector, a ground fault detector, and a health status gauge. A vehicle interface program is utilised for mission programming as well as post-mission analysis, though the craft’s operations will be monitored in real-time during MCM missions.

As with other craft in the same series, the Royal Navy’s newest MCM UUVs can be operated simultaneously by a single control centre on a vessel of opportunity.

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