VESSEL REVIEW | ITS Trieste – Italian Navy welcomes new large landing ship into service

A new landing helicopter dock (LHD) was recently commissioned into service with the Italian Navy.

Named after the famed seaport city in northeastern Italy, the RINA-classed Trieste is also the largest ship in the Italian Navy with an LOA of 245 metres (804 feet), a beam of 47 metres (150 feet), and a displacement of approximately 38,000 tonnes at full load.

The ship is also notable for having distinct fore and aft island superstructures similar to what is fitted on each of the two Queen Elizabeth-class aircraft carriers of the UK Royal Navy.

Significant amphibious transport capacities

The LHD can carry a fully equipped battalion of 600 troops in addition to a 460-strong crew. The floodable well deck measuring 50 by 15 metres (160 by 49 feet) can house various types of NATO small and medium landing craft (both traditional monohulls and air-cushioned landing craft), fast attack boats, and rigid inflatable boats (RIBs), while the 900-square-metre (9,700-square-foot) garage deck directly above it can accommodate both wheeled vehicles and tracked armoured fighting vehicles such as the Italian Army's Ariete main battle tank.

The RIBs can also be launched and recovered using dedicated side davits. Larger cargo cranes with lifting capacities of 30 tonnes are fitted for loading and unloading of non-vehicle materiel. Space is also available for ammunition storage and tanks carrying potable water and fuel for use by the ship’s embarked vehicles.

Capable of air operations

Trieste also has a 7,400-square-metre (80,000-square-foot) flight deck with dedicated flight control via the aft island; elevators going to and from the hangar deck below for use by a mix of utility and attack helicopters and up to 20 F-35B Lightning II short take-off and vertical landing (STOVL) fighter aircraft; and a 12-degree “ski jump” take-off aid for the F-35s.

The hangar also boasts fire barriers and overhead cranes for moving materiel and performing maintenance on aircraft.

Being able to embark fighter aircraft is deemed only a secondary function of the LHD, as the ship will be used primarily for amphibious operations (and because the purpose-built aircraft carrier Cavour already serves as the Italian Navy’s main means of deploying seaborne fixed-wing air power).

If needed, the LHD can also support unmanned aerial vehicle (UAV) operations and serve as a command and control (C&C) ship within an amphibious task force. This is made possible by a dedicated C4I space that covers 430 square metres (4,600 square feet) and a combat information centre spread across 220 square metres (2,400 square feet).

Among the notable electronics in C4I space are a Leonardo combat management system with 20 multi-function displays.

Versatile propulsion arrangement

The propulsion system adopts a combined diesel or gas or electric (CODOGOL) setup consisting of two Rolls-Royce MT30 gas turbines, two MAN 24,000kW (hp) 20V32/44CR diesel engines, four MAN 9L32/44CR 20,960kW generators, and two GE 2,250kW electric motors driving two five-bladed, controllable-pitch propellers via shaftlines. The propulsion also includes Renk gearboxes and Fincantieri rudders.

The LHD can reach a top speed of 25 knots using the gas turbines, whereas diesel-only and electric-only sailing modes will yield speeds of 18 and 10 knots, respectively. At a cruising range of 16 knots, the ship can sail up to 7,000 nautical miles. The ship can also stay out at sea for a maximum of 30 days.

To enhance survivability, the propulsion machinery is split across separate compartments.

Large size permitting humanitarian response capability

The LHD may also be employed for secondary peacetime missions such as humanitarian assistance and disaster relief (HADR), search and rescue (SAR), and medical support.

To perform these roles, the vessel is equipped with facilities for supplying potable water and electrical power as well as a 770-square-metre (8,300-square-foot) NATO Role 2E hospital. This space boasts surgical, intensive care and isolation facilities, recovery rooms, a dental office, and radiology rooms.

Should additional space be needed to house patients, container modules with beds can be fitted on board.

For self-defence, the LHD is fitted with Leonardo equipment consisting of three 76mm naval guns, three remotely controlled 25mm autocannon with EO/IR sensors for employment against missiles and hostile boats, and underwater and aerial decoy launchers. The only guided weapons are a battery of 32 Aster surface-to-air missiles.

Leonardo also supplied the ship’s obstacle avoidance and torpedo detection sonars.