VESSEL REVIEW | Apalachicola – US Navy fast transport fitted with autonomous navigation systems

The US Navy recently took delivery of the future USNS Apalachicola, the thirteenth Spearhead-class expeditionary fast transport (EPF) ordered from Austal USA.

The second US Navy ship named after the city of Apalachicola in Florida, the EPF is also the first Spearhead-class ship with capabilities for V-22 Osprey flight operations and enhanced medical support, though the ship retains the standard Spearhead-class' flight deck designed for conventional utility and heavy lift helicopters.

As with other EPFs, Apalachicola has a length of 337 feet (103 metres), a beam of 93.5 feet (28.5 metres), and a draught of 12.5 feet (3.83 metres). The vessel is designed to operate in shallow waterways and is capable of a wide range of activities including the high-speed transportation of troops, military vehicles such as main battle tanks, and equipment totalling 600 tons (544 tonnes) up to 1,200 nautical miles.

The EPF has an off-load ramp that allows vehicles to quickly drive on and off the ship. The ramp is suitable for the types of austere piers and quay walls common in developing countries. The shallow draught also enhances littoral operations and port access, making the vessel ideal for supporting military and humanitarian operations at small or damaged ports.

Power is provided by four MTU 20V8000 M71L diesel engines connected to ZF 60000NR2H gearboxes. This configuration delivers a maximum speed of 43 knots, though operational sailings at full load will typically not exceed 35 knots.

EPFs have a core crew of 21 people, with airline style seating for more than 312 embarked forces and fixed berthing for 146.

One of the highlights of Apalachicola's development was the use of the vessel itself in performing a series of planned test events assessing autonomous capabilities integrated into the shipboard configuration – thus demonstrating that a large ship can become a self-driving platform – between June and August 2022. Known as Unmanned Logistics Prototype trials, each test event increased the perception capabilities and complexity of behaviours demonstrated by the installed autonomous systems. Test evolutions included point-to-point autonomous navigation, vessel handling, transfer of vessel control between manned and unmanned modes, and even autonomous station keeping, where Apalachicola was able to match the course and speed of another vessel that was also participating in the trials.

Apalachicola is being operated by the navy via the Military Sealift Command (MSC). Although it is a non-combatant ship like other MSC vessels, the EPF is nonetheless fitted with four mounts for Browning M2 12.7mm machine guns to provide limited self-defence capability against small surface and airborne threats.