Rolls-Royce MT30: Powering Through the Water1 April 2008
The MT30 marine turbine gas engine has come a long way since its launch. Specially tailored for commercial and naval applications, Al Elliott looks at the design and technology used in developing the MT30 – the world's most powerful marine engine – and how it has fared on the open seas.
The MT30 marine turbine gas engine – Rolls-Royce's very own monster of the sea. When it came onto the market back in 2004 it simply blew the competition out of the water. Raising the benchmark for sheer power, propulsion and dynamic ability, the MT30 delivered an impressive, market leading, power-to-weight ratio that has since made it the master of the sea.
ABS and DNV certified to deliver 36MW flat rated up to 38°C and 40MW at 15°C, it offers excellent performance options for high-power shipboard applications, either in mechanical or electrical generator set applications.
The MT30 was engineered to meet the needs of both high-powered naval ships and commercial vessels. Target naval applications include frigates, destroyers and aircraft carriers.
Since it first rolled off the production line in 2004, the MT30 has been chosen for use in a number of high spec naval applications. In particular, a good relationship has been developed with the US Navy.
In July 2005, the MT30 completed the arduous American Bureau of Shipping (ABS) testing programme required by the US Navy. Carried out on a specially built testbed in Bristol, the programme ran for 1,500 hours and 198 cycles – including running on full power in ambient temperatures of over 38°C.
US NAVY LITTORAL COMBAT SHIP
The Littoral Combat Ship (LCS) had a power requirement that would support operational flexibility, speed and manoeuvrability – and the MT30 fitted the bill. Capable of sustained speeds over 40kt, the fast agile monohull is powered by two MT30 turbines in a combined diesel and gas turbine arrangement that drives four Rolls-Royce Kamewa water jets.
The LCS is an entirely new class of surface warship, designed for close-to-shore threats in coastal waters. Flexible in its deployment, it is fast and manoeuvrable and used for a wide range of mission criteria, including mine warfare, anti-submarine warfare and humanitarian relief.
The first of its class, Freedom was launched in 2006 and commissioned in 2007. Work began on the second in early 2007. All in all, the entire LCS programme is expected to reach a total of 57 warships.
In 2005, under contract to Northrop Grumman, test runs were begun on the DD(X) destroyer programme (since renamed as the DDG-1000 Zumwalt Class Destroyer).
Based at the Philadelphia land-based test site, the MT30 drives the integrated power system engineering development model for the programme – providing risk mitigation for the main propulsion systems.
The destroyer programme returned to the MT30 in 2007, when the US Navy purchased four generator sets for what is claimed as their most advanced surface combatant ship yet.
Commenting on the deal, Patrick J Marolda, Rolls-Royce president – naval said "this decision represents an unequivocal vote of confidence in Rolls-Royce and our ability to deliver power solutions to the US Navy and the global market."
Delivery of the generator sets begin in 2009, with the first ship delivery planned for 2012.
GAS TURBINE ENGINE FOR MARINE MARKET
As a new product coming into the naval sector, the MT30 gas turbine was the latest in the line to benefit from the heritage of the Rolls-Royce Trent family.
Building on the phenomenally successful Trent 800 aero-engine – which achieved a 44% share of Boeing's 777 programme – the MT30 answered the prayers of naval and commercial shipping operators looking for both more speed and durability.
Where two engines went before, now came one – a single MT30 being in the position to replace two conventional boost turbines. For propulsion system designers this translated to greater flexibility, reduced operational overheads and higher power and efficiency.
AERODERIVATIVE TECHNOLOGY FOR MARINE PROPULSION
Derived from Rolls-Royce's core aero engine technology, the MT30 is a twin-spool, high-pressure ratio gas generator, with an eight stage variable geometry intermediate pressure compressor and a six stage high pressure compressor.
It shares many of the technology features of the Trent engine, utilising the latest blade-cooling technologies and advanced 3D design of components such as the blades and vanes used in the compression system.
One advantage that the MT30 had right from the outset was the 80% commonality it shares with the Trent aero engine – its proven and reliable cousin from the aerospace sector. By adapting its use for the marine sector – while at the same time reducing the number of components by 60% – Rolls Royce were able to meet the growing demand for higher power propulsion solutions without reinventing the wheel.
MT30 GAS TURBINE FEATURES
The gas turbine itself is of a modular construction comprised of a robust, four-stage power turbine derived from the Trent 800 and Industrial Trent models. Measuring just under 4.5m in length, the total housing of the entire generator set comes in at a very compact 8.6m long.
The total module weight – when packaged as a skid-mounted generator set – is around 77,000kg, giving an impressive power-to-weight ratio.
Due to its compact size and comparative light weight, the MT30 offers great flexibility to the ship design process. Its modular nature is ideal for new build projects and also supports fast turnaround maintenance programmes.
Other features include full authority digital control, through fully integrated alarm, monitoring and control functions including overspeed protection. The system can be operated through a local touch screen providing control of the turbine and support systems.
The engine enclosure is optimised for system accessibility and maintenance and permits top or front removal of turbine change units. It also has its own integral fire protection system.
FLYING INTO THE FUTURE – CVF AIRCRAFT CARRIER
The MT30 is the down-select power solution for the Royal Navy's Future Aircraft Carrier (CVF). At a total estimated cost of £3.9bn, two CVF Carriers – HMS Queen Elizabeth and HMS Prince Of Wales – are due to enter service in 2014 and 2016 respectively.
The carriers are designed for operating 34 to 40 STOVL (short take-off and vertical landing) aircraft with the capability to accommodate catapult and arrester gear. Successors to the Invincible Class, they will be the biggest and most powerful surface warships ever constructed for the Royal Navy.
Propulsion is delivered by integrated full electric power from four gas turbines. Initially, a lesser power model, the Rolls-Royce WR-21, was being looked at.
As the CVF design developed, so the power requirements increased. The MT30, with its 36MW capability compared to 25MW, has since been looked at as being in the position to deliver the required power solution.
2007 was a big year for Rolls-Royce's marine sector. The success of the MT30 has been a contributory factor – particularly in the naval market – underpinned by continued business with the US Navy in the form of the DDG 1000 Zumwalt Class Destroyer.
With its marine order book doubled in size from 2006 to a massive £4.7bn, and growth into the ever important South East Asian merchant shipbuilding sector, 2008 looks set to be even bigger – for both Roll's Royce marine and the MT30.