The Rolls-Royce MT30 marine gas turbine has been selected to power Australia’s new fleet of general-purpose frigates, following the Royal Australian Navy’s decision to adopt an upgraded variant of Japan’s Mogami class, designated the New FFM or 06FFM, as its replacement general-purpose frigate platform.

The propulsion arrangement in the Mogami class is a combined diesel and gas (CODAG) configuration comprising a single MT30 gas turbine and two MAN 12V28/33D STC diesel engines, driving twin shafts equipped with controllable-pitch propellers, to achieve a maximum speed exceeding 30knots. The Mogami class marks the first installation of a CODAG system on any Japan Maritime Self-Defense Force ship. Australia has confirmed the MT30 will continue in that role for its fleet. The first of the frigates is scheduled for delivery to Australia in 2029 and operational service in 2030, with the initial three vessels to be built in Japan by Mitsubishi Heavy Industries before production transitions to Australia.

The MT30 is derived from the Rolls-Royce Trent 800 aero engine, retaining approximately 80% parts commonality with it. The current power rating is 36MW, with a maximum output of 40MW available, and the unit is flat-rated to 38°C ambient. Thermal efficiency is quoted at 40%, with operating efficiency maintained at loads down to 25MW.

The core design is based on a twin-spool arrangement, with a high-pressure ratio gas generator and a four-stage free power turbine. The intermediate pressure compressor has eight stages of variable geometry and the high-pressure compressor contains a further six stages. Designed with 50 to 60% fewer parts than other aero-derivatives, it carries type approval from both ABS and Lloyd’s Register.

The core gas turbine change unit, which would be exchanged at major maintenance intervals, weighs 6,500kg including its power turbine. The total weight of the complete gas turbine module, including its enclosure and ancillaries, is approximately 30,000kg. The Compact Package has a footprint of 8.6m x 2.7m. The engine can be configured for mechanical, electrical or hybrid drive. The MT30 is already selected to power Australia’s Hunter-class frigates.

The engine is designed, assembled and tested at Rolls-Royce’s Bristol facility and is in service with several navies globally, including the UK Royal Navy’s Queen Elizabeth-class aircraft carriers, the US Navy’s Zumwalt-class destroyers (where the MT30 operates as a generator prime mover within an integrated electric propulsion system rather than a direct mechanical drive), and the Republic of Korea Navy’s Daegu and Chungnam-class frigates, the latter employing a combined diesel-electric or gas arrangement with two MT30s per vessel combined with diesel-electric motors.

In addition to the MT30, the upgraded Mogami-class frigates will be equipped with mtu Series 4000 diesel generator sets from Rolls-Royce Power Systems, supplied through licensed partner Daihatsu InfinEarth, providing onboard power generation across ship systems. The Series 4000 covers a power range from 1,125 to 3,250kWe and has accumulated more than 250 million operating hours across its service life.

The selection reinforces Rolls-Royce’s position as a propulsion supplier across Australia’s naval modernisation programme, which also includes the AUKUS nuclear-powered submarine commitment, for which Rolls-Royce Submarines is set to provide reactors.

This article appeared in Technical, TNA May/June 2026.