In any marine application where the usage profile requires operation at different speeds for a considerable time, using one engine type is not always the most efficient solution. Vessels that are required to operate at a slow / cruising speed yet be able to accelerate to a higher speed in a short time usually turn to a combined operation configuration of more than one diesel engine or diesel and gas turbine.

Combined operation of diesel and / or gas turbine (CODAG / CODOG) is particularly popular in naval and megayacht applications where high speed can be reached in minutes. Firing up a large diesel from cold requires a warming up period to prevent serious damage, whereas a gas turbine can produce full power within one or two minutes.

Caption: ROK Navy’s PK(X) Fast Attack Craft successfully completed sea trials recently. 
Image credit: GE Marine

GE Marine has recently reported the successful sea trials of two new patrol vessels built by STX Jinhae, South Korea using gas turbines in combination with diesel engines. The vessels concerned are number eight and nine of the Republic of Korea Navy projected fleet of twenty Gumdoksuri Class, Fast Attack Craft. The 570 ton vessels have an LOA of 206 ft (63 m), beam of 29.5 ft (9 m) and draft of 16.4 ft (5 m).

Each of two MTU 16V 1163 TB93 diesels of 7,940 hp (5,920 kW) at 1300 rpm drive propellers.
CODAG operation for high speed operation, is simply achieved using a single boost waterjet connected via a combining gearbox to two GE LM500 gas turbines, each with an output of 5,450 hp (4,050 kW). Maximum speed is in excess of 40 kn and range is 2,000 nautical miles at a cruising speed of 15 kn on diesels.

Caption: GE LM500 has an output power of 5,450 hp (4,050 kW).
Image credit: GE Marine

South Korean conglomerate and shipyard Daewoo Shipbuilding & Marine Engineering (DSME) last month announced their first export order for submarines. The order is for  three modified Type 209 diesel electric submarines for the Indonesian Navy: two boats will be built in South Korea and the third one at the Indonesian shipyard of PT PAL in Surabaya. The total value of the contract is approximately US $1.1 billion and construction is due to commence this month with planned commissioning dates of 2018.

Caption: Republic of Korea Type 209/1200 Class submarine Chang Bogo (SSK 061)
Image credit: PH1 David A. Levy, US Navy

The conventional diesel electric Type 209 submarine is a development of Howaldswerke-Deutsche Werft (HDW), now ThyssenKrupp Marine Systems (TMS), Germany for export and is designed to be produced in local yards. The original Type 209/1100 was developed in the 1960s and has been successively improved through type 209/1200, 209/1300, 209/1400 and 209/1500. Under a technology transfer agreement from 1988, DSME acquired rights allowing it to produce the submarines independently from HDW. Although never ordered by the German Navy, the Type 209 is one of the most popular diesel electric submarine classes with 61 boats in service with the navies of 13 countries.

The Indonesian DSME209 Class submarine is a conventional attack class submarine and is larger than the Korean Navy’s original Chang Bogo Type 209/1200 Class. It has an LOA of 200 ft (61 m) with a 20.7 ft (6.3 m) hull diameter and a surface displacement of 1,400 tons. There is accommodation for a crew of up to 40 man. Eight tubes are provided for delivery of torpedos and other weapon systems including missiles.

The propulsion system comprises four MTU 12V396 SE84 gensets each rated at 700 kW at 1800 rpm. An electric motor driving a single screw propels the boat on the surface at 11 kn, submerged up to 22 kn. Submerged range is 400 nautical miles (740 km) at 4 kn, 8,000 nautical miles snorkeling at 10 kn and 11,000 nautical miles surfaced at 10 kn.

Caption: December 2011 contract signing ceremony between the Indonesian
Ministry of Defence and Daewoo Shipbuilding & Marine Engineering Co.Ltd.
Image credit: Daewoo Shipbuilding & Marine Engineering Co.Ltd.

Delivered to the Republic of Cape Verde last month, the Damen Stan Patrol SPA 5009 is based on their Fast Crew Supplier (FCS) 5009. This vessel features a single ‘Axe Bow’ which delivers high speeds with low fuel consumption. Although more than 60 Damen Sea Axe vessels have already been delivered as Crew Boats and FCS, the Cape Verde order is the first Offshore Patrol Vessel version.

Caption: Tthe Damen Stan Patrol SPA 5009 (foreground) is based on their Fast Crew Supplier (FCS) 5009
and features a single ‘Axe Bow’ which claims to deliver high speeds with low fuel consumption.
Image credit: Damen Shipyards.

The Sea Axe concept was developed for patrol boats by a team combining Damen Shipyards, Delft Technical University, the US Coast Guard, the Royal Netherlands Navy, and Maritime Research Institute of the Netherlands (MARIN). Rather than bouncing over waves, the Sea Axe design cuts through them, limiting speed degradation due to wind and waves.
The wheelhouse is in weight saving aluminum, however extensive Finite Element analyses showed that steel was the best construction material for the Stan Patrol 5009 hull, enabling it to sail at maximum speed under all circumstances without distressing the crew or the ship itself. There is accommodation for 18 persons in 11 cabins.

The LOA is 50 m, beam 9.4 m and draft 3.5 m. A propulsion system of four main engines driving four shafts via Reintjes WVS 730 reverse reduction gearboxes with four fixed pitch propellers, delivers a maximum speed of 23 knots. Main engines are Caterpllar C32 each delivering 1450 hp (1081 kW) at 2300 rpm giving a total installed power of 4,324 kW. There are two 107kVA gensets producing 230/440V at 50 Hz. According to the builders, the SPA 5009 can be fitted with more powerful engines up to a total power of 12,000 kW to give a speed in the region of 35 kn.

In keeping with its duties, the patrol ship has a launch and recovery ramp built into the stern for a 7.5 m RIB powered by an inboard diesel driving a waterjet. This boat has a crew of six persons and a top speed of about 30 kn.

Caption: The Caterpllar C32 is rated at 1450 hp (1081 kW) at 2300 rpm.
Image credit: Caterpillar Inc

The striking appearance of the remarkable GHOST high-speed attack craft revealed to the public last year by Juliet Marine Systems, Inc., (JMS) of Portsmouth, NH, applies supercavitation technology to offer new capabilities in high speed craft performance.

Caption: GHOST, at rest with hull immersed during recent sea trials.
Image credit: PRNewsFoto/Juliet Marine Systems, Inc.

Although few propulsion details have been released what we do know is that the vessel has a centre hull and two movable sponsons allowing the main hull to run clear of the surface at higher speeds. At rest the sponsons move horizontally outward allowing the center hull to lower and float on the surface: thereby allowing the crew and cargo or passengers to embark / disembark. 
At speed the wings carrying the sponsons move to a position approximately 30 degrees from vertical raising the center hull clear of the water surface.

Despite the scant details of the propulsion system as yet made public, propulsion power is provided by “gas turbines.”  Looking at the material available, there are large grilles on the side of the main hull, suggesting that behind them the gas turbine are located - probably two in number, possibly driving generators.

Caption: GHOST showing the torpedo-like sponsons
Image credit: PRNewsFoto/Juliet Marine Systems, Inc.

The sponsons somewhat resemble the shape used in some SWATH designs but are perfectly round like a torpedo. I’m guessing but probably within the torpedo shaped sponsons are electric motors powering pulling propellers, perhaps counter-rotating. As to the supercavitation technology, the Soviet Union developed a supercavitating torpedo in the 1970's called Shkval (Russian for squall), with a speed in excess of 200 kn. It is rocket powered and ducts some of the exhaust gases to the front of the torpedo so it slides through the water in a gas bubble cloud. JMS however, is not claiming speeds anything like this but in the absence of detail, perhaps ducting the gas turbine’s exhaust gases to the torpedo, is part of the “secret” of GHOST - time will tell!

Caption: Artists impression of GHOST at speed.
Image credit: Juliet Marine Systems, Inc.

   
The Brazilian Navy is to buy three Offshore Patrol Vessels from BAE SYSTEMS, UK with two ships being delivered in 2012 and the third in 2013. The contract includes supply of ancillary support services and a technology transfer agreement allowing licensed production of further vessels in Brazil. The three vessels were originally built for Trinidad and Tobago and became available following contract cancellation. A technology transfer arrangement was made for the 90m OPV with Thailand whereby a ship was built to this design by Bangkok Dock for the Royal Thai Navy.

Caption: One of the three BAE SYSTEMS 90m OPVs sold to Brazil.
Image credit: BAE SYSTEMS

The 90 meter Offshore Patrol Vessel is designed to perform Economic Exclusion Zone management roles, including the provision of maritime security to coastal areas and disaster relief operations. The 90 meter patrol ship design is based on the smaller 80 meter River Class patrol vessels presently in service with the Royal Navy.

The LOA is 295 ft (90 m), beam is 44 ft (13.5 m) and  displacement is 1,800 tons. The ship is  operated with a crew of 36 and accommodation for up to 70 persons is provided.

A conventional propulsion layout is used comprising twin high speed MAN 16V28/33D diesels rated at 7,350 kW at 1,000 rpm driving Wärtsilä propellers. During sea trials, the ship achieved a speed of 25.4 kt and completed turning circles in 3.5 ship lengths and a stopping distance of 3.7 ship lengths. Range is 5,500 miles and endurance 35 days.

Caption: During sea trials turning circles of 3.5 ship lengths were achieved.
Image credit: BAE SYSTEMS

LCAC 91 Achieves Navy's Fastest Maritime Surface Craft Speed on Algal Fuel Blend

From Naval Sea Systems Command Public Affairs

PANAMA CITY, Fla. (NNS) -- The Navy successfully concluded its final alternative fuel demonstration for the year today with the Dec. 7-9 operational tests of the 50/50 algae-derived, hydro-processed algal oil and petroleum F-76 blend in a landing craft air cushion (LCAC) amphibious transport vehicle.

The tests also marked the fastest speed achieved to date by a U.S. Navy surface craft using alternative fuel blends, as LCAC 91 reached 50 knots, Dec. 7. The fastest speed demonstrated on the 50/50 algal blend in previous tests was 44.5 knots by the Riverine Command Boat (experimental) (RCB-X) in October 2010 at Naval Base Norfolk, Va.

"Our Navy is working to be resilient to any potential energy future. Pursuing sustainable resources, such as alternative fuels that are drop-in replacements, assures our performance and mobility while protecting us from the volatility of the fossil fuel market. This demonstration is another Wright Brothers-moment for the Navy. We have shown that we can achieve more than 50 knots on the water and Mach 1.7 in the air - all on biofuel blends," said Rear Adm. Philip Cullom, director, Chief of Naval Operations Energy and Environmental Readiness Division.

LCACs move elements of a Marine Air/Ground Task Force - weapons systems, equipment, cargo, and personnel - from ship to shore and over the beach. The vehicles have four gas turbine engines, and two generators that traditionally run on NATO F76 or NATO F44. They have a 7,000 gallon fuel capacity, an average range of 200 nautical miles, and can carry up to 150,000 pounds.

"For the test, the craft was operated out in the Gulf of Mexico using two different fuel configurations so we could compare the craft's operations as powered by each fuel type," said Naval Sea Systems Command's Navy Fuels Engineering Manager Richard Leung. "After draining the diesel, LCAC 91 received approximately 5,000 gallons of the 50/50 algal blend. We assessed the engine performance capabilities on the biofuel blend, and collected data on engine torque, acceleration rates, craft speed, fuel flow rates, propeller pitch, compressor discharge pressure, and inlet and exhaust gas temperatures"

Mechanical engineers bore scoped the engines and collected the technical data. LCAC operators then provided input on how the craft performed and operated.

"We are going to compare how the engines performed during the test both on the straight diesel and on the 50/50 mix. Results from the comparison will help us assess the performance of the fuel," said mechanical engineer Ben Canilang, NSWC Carderock's Naval Ship Systems Engineering Station, Philadelphia, Pa.

"To see what type of numbers came out, we connected a laptop with a harness that read into our digital and analogue data collectors," said mechanical engineer Peter Diamond. "The type of analysis is simply comparing numbers. We'll plug in a stream of numbers and compare results from each of the tests."

"The test run on the 50/50 alternative fuel mix was very successful," said Scott Feenstra, mission director, Landing Craft Air Cushion, NSWC Panama City Division. "LCAC 91 performed without issue. The operators were able to use high power; and reported that the craft handled beautifully and without problems."

Meeting the secretary of the Navy's call for a drop-in fuel replacement, no changes were required to the LCAC or fueling equipment infrastructures for the test. Alternative fuel efforts also support the secretary's overall energy strategy to increase energy security and safeguard the environment; as well as his goals to demonstrate a 'green' strike group by 2012, and deploy a strike group composed completely of alternatively powered ships, "The Great Green Fleet," by 2016.


Watch video: http://www.youtube.com/watch?v=0TiX2VMiwJo&feature=plcp&context=C26ff4UDOEgsToPDskLI1bKQu-WZOdEY0mx1dg-_>

Navy to Demonstrate Biofuel Use During Exercise
By Karen Parrish
American Forces Press Service

WASHINGTON, Dec. 5, 2011 - The U.S. Navy will employ a biofuel blend to power aircraft and most vessels participating in a maritime exercise that's slated to be conducted near Hawaii next summer, senior officials told reporters today.

Navy Secretary Ray Mabus and U.S. Department of Agriculture Secretary Tom Vilsack held a conference call with reporters this morning to discuss a contract the Defense Logistics Agency announced last week for 450,000 gallons of biofuel that will power a Navy carrier group during a maritime exercise next summer.

The contract is the largest government purchase of biofuel in history, and provides $12 million to suppliers Solazyme and Dynamic Fuels LLC, a joint venture of Tyson Foods, Inc. and Syntroleum Corporation.

Solazyme's biofuel is algae-based, Mabus explained, while Dynamic's is made from used cooking oil and non-food-grade animal fats.

So-called drop-in fuels can work without engine modifications, and Mabus noted the Navy has already certified that its ship and aircraft engines will perform on the new fuels.

He said the fuel "met all our criteria -- that it be a drop-in biofuel, that come from nonfood sources, and that it not increase the carbon footprint."

The fuels will be combined in a 50-50 blend with petroleum-based diesel and aviation fuel to power the U.S. ships and aircraft taking part in the Rim of the Pacific or RIMPAC exercise, the world's largest international maritime exercise, scheduled to take place off Hawaii next summer, the Navy secretary added.

The carrier that anchors the strike group is nuclear-powered, Mabus noted, but all other Navy craft involved in the exercise will use biofuel.

"We think that this represents a major step in energy independence for the United States in making the United States Navy a better war-fighting operation," Mabus said, "and in reducing our dependence on unstable sources of foreign energy, as well as reducing the budget shocks that come with buying fuel from either potentially or actually unstable place on earth."

Use of fossil fuels "is a very real threat to our national security, and to the U.S. Navy's ability to protect America and to project power overseas," Mabus added.

While the DLA purchase is a small fraction of the Navy's annual fuel consumption of 1.26 billion gallons, supporting the nation's fledgling biofuel industry will ultimately make the Navy "better war fighters," the Navy secretary said.

The Navy plans to follow the RIMPAC demonstration with a 2016 multi-month carrier group deployment using 50 percent biofuel for surface ships and aircraft, Mabus said.

The Navy has throughout history led new developments in fuel, he noted: from sail to coal in the 1800s, from coal to oil in the early 1900s to nuclear power in the 1950s.

"We're going to lead once again by helping establish a market for biofuels now," Mabus said.
Biofuel use lessens America's dependence on foreign oil and fossil fuels, he said, and increases the nation's ability to compete in the global energy market.

"This is not only going to help the Navy ... [and] our national security, but it's going to help the farmers and agriculture in the United States," Mabus said.

Vilsack said the biofuel purchase is a turning point in the partnership that includes the U.S. Department of Transportation, the Navy and the Energy Department under President Barack Obama's "Blueprint for a Secure Energy Future," which tasked the three to advance a domestic industry capable of producing "drop-in" biofuel substitutes for diesel and jet fuel.

More than 300 facilities in the United States are now producing ethanol and biodiesel, he noted.

Agriculture officials have this year helped finance loans for two refineries that will produce biofuel from nonfood feed stocks, Vilsack said, and they expect to announce additional projects next year.

Vilsack noted that Agricultural Research Service and National Forest Service scientists have been working with industry to identify and develop additional nonfood, "feed stocks" for biofuels, and the Forest Service announced $118 million in grants for feedstock development.

Agriculture Department officials are also researching supply chain management to ensure biofuel products can efficiently reach the Navy market and other emerging markets, including the nation's commercial air carriers, he added.

"Today's announcement, I think, underscores the fact that the future for the Navy ... [and] this country lies in energy security, and basically controlling our own destiny by producing our own fuels in a creative and innovative way," Vilsack said.

Navy Secretary and USDA Secretary Announce Largest Government Purchase of Biofuel

From Secretary of the Navy Public Affairs

WASHINGTON (NNS) -- Secretary of the Navy Ray Mabus and U.S. Department of Agriculture Secretary Tom Vilsack announced the Defense Logistics Agency (DLA) signed a contract to purchase 450,000 gallons of advanced drop-in biofuel, the single largest purchase of biofuel in government history, Dec. 5.

While the Navy fleet alone uses more than 1.26 billion gallons of fuel each year, this biofuel purchase is significant because it accelerates the development and demonstration of a homegrown fuel source that can reduce America's, and the military's, dependence on foreign oil.

The Defense Department will purchase biofuel made from a blend of non-food waste (used cooking oil) from the Louisiana-based Dynamic Fuels, LLC, a joint-venture of Tyson Foods, Inc., and Syntroleum Corporation, and algae, produced by Solazyme. The fuel will be used in the U.S. Navy's demonstration of a Green Strike Group in the summer of 2012 during the Rim of the Pacific Exercise (RIMPAC), the world's largest international maritime exercise.

As part of his energy security goals, outlined in March 2011 in the "Blueprint for a Secure Energy Future," President Obama directed the Departments of Agriculture, Energy and Navy to work together to advance a domestic industry capable of producing "drop-in" biofuel substitutes for diesel and jet fuel.

Responding to that challenge, in August 2011, the Secretaries of Agriculture, Energy and Navy announced an intention to invest up to $510 million during the next three years in partnership with the private sector to produce advanced drop-in biofuel to power military and commercial transportation. While that investment awaits Congressional action, today's announcement uses the existing authority - leveraging Defense Department procurement - to support this energy security goal.

"The Navy has always led the nation in transforming the way we use energy, not because it is popular, but because it makes us better war fighters," said Mabus. "This unprecedented fuel purchase demonstrates the Obama Administration's commitment to seeking energy security and energy independence by diversifying our energy supply."

"In March, the President challenged me, Secretary Mabus, and Secretary Steven Chu to work with the private sector to cultivate a competitively-priced-and domestically produced-drop-in biofuel industry that can power not just fighter jets, but also trucks and commercial airliners," said Vilsack, "Today's announcement continues our efforts to meet that challenge. This is not work we can afford to put off for another day."

The biofuel will be mixed with aviation gas or marine diesel fuel for use in the Green Strike Group demonstration. It is a drop-in fuel, which means that no modifications to the engines are required to burn the fuel. Its cultivation did not interfere with food supply and burning the fuel does not increase the net carbon footprint. In preparation for this demonstration, the Navy recently completed testing of all aircraft, including F/A-18 and all six blue Angels and the V-22 Osprey, and has successfully tested the RCB-X (riverine command boat), training patrol craft, self defense test ship, and conducted full-scale gas turbine engine testing.

DLA will pay half the price for the Green Strike Group biofuel than it paid for biofuel for testing in 2009. Increased demand will likely continue this trend toward more cost-effective biofuel. Renewable jet fuel produced by Dynamic Fuels has already been used in regularly scheduled commercial airline flights by KLM Royal Dutch Airlines, Finnair, Thomson Airways, and Alaska Airlines.

"This contract clearly demonstrates that we're building momentum for the continued commercialization of advanced renewable fuels production here in the U.S.," said Andy Rojeski, a management committee member for Dynamic Fuels, a joint venture between Tyson Foods, Inc. and Syntroleum Corporation. "We believe the federal government's commitment to procure more energy from renewable sources will help make our high performance, environmentally friendly fuel more cost competitive, potentially creating more jobs in the biofuels industry."

"This historic contract is a major step forward for America's energy security and the advanced biofuel industry in our country. Solazyme has delivered more than 360,000 liters of 100 percent algal derived renewable diesel to the U.S. Navy for their fuel certification program to date. The United States leads the world in advanced biofuel technology, and the Departments of Agriculture, Energy and the Navy have been instrumental in coming together to spur commercialization and grow our lead," said Jonathan Wolfson, CEO, Solazyme. "We are honored to be working with the U.S. Navy and DLA-Energy in driving forward the Navy's effort under Secretary Ray Mabus to source 50 percent of its energy from renewable sources by 2020. And we are proud to be teaming up with Dynamic Fuels on this contract."

For more news, visit www.navy.mil.

Russia plans to have ten new nuclear powered attack submarines by year 2020, the first now delayed until the end of 2012; in the meantime the Navy has to make the best they can of it with an ageing fleet. A case in point –  the Russian nuclear submarine SSN Voronezh  (K-119) –  an Oscar ll class veteran ‘cold war’ warrior launched in 1988 came out of the Zvezdochka Ship Repair Centre last week after entering dock (no less than five years’ ago) for ‘emergency’ repairs to the main steam turbine engine and a change of uranium fuel in her two reactors. According to Russian Navy News Service the warship has now been repaired and refitted so that her service life with Russia’s Northern Fleet will be extended for another three years. One more cold war nuclear submarine veteran has already replaced Voronezh in the repair dock.

Russian Nuclear Submarine SSN Voronezh: Photo courtesy of JSC Zvezdkochka Repair Centre

Analysts consider that defense shipbuilding capability has deteriorated to the extent that the Russian Navy may be left with few modern operational warships by the end of the decade unless urgently needed funding is provided. Overhaul and repair of a fleet well past it’s ‘sell-by date’ carries on, while two state-of-the-art Mistral (L9013) amphibious assault ship/helicopter carriers are on order from France to plug another gap in the capabilities of the surface fleet.

Russian Navy Order for Mistral Class Amphibious Assault Ship/Helicopter Carriers

Reportedly the first tranche of advance cash was recently paid by Moscow to French defense shipbuilder DCNS under a $1.2-billion contract for the construction of the first two Mistral class ships and construction is already underway. The contract, which includes the transfer of advanced naval technology, specifies delivery in 2014 and the second assault ship a year later.

According to Russian news source Ria Novosti the hulls of the third and fourth ships of the class will be built in Russia, the United Shipbuilding Corporation and the Baltiisky Zavod shipyard having signed a 2.5 billion ruble ($80 million) contract to this effect on Friday last.

Mistral Amphibious Assault Landing Ship at Toulon: Photo credit – FaceMePLS – Twitter (CCL)

Propulsion system of France’s Mistral-class is diesel-electric (two currently in service with the French Navy are propelled by azimuth thrusters) with four Wärtsilä  (3 x 16V32 and 1 x 18V200) marine diesel engines powering the two electric motors to give a 19 knot service speed.

Sources indicate these ships can carry 16 medium or 35 light helicopters and the Russian version of the Mistral class is expected to have eight Ka-52K and eight Ka-29 helicopters as well as 70 armoured vehicles for amphibious operations, carried to the shore by 4 landing craft launched from the stern. It is not yet clear what armaments the new Russian versions will have.

The South Korean Navy is augmenting their amphibious forces capability with the addition of four larger landing ships. This new class designated LST-2 has an LOA of 127 m and displacement of 4,500 t. The present largest LSTs are three Alligator Class LSTs with LOA of 370 ft (113 m).

Caption: ROK’s Biro Bong is one of three Alligator Class LSTs with LOA 370 ft (113 m) which will be
augmented with the addition of four LST-2s. An air cushion landing craft is in the foreground.
Image credit: U.S. Navy photo by Mass Communication Specialist Chief Ty Swartz

The first in class vessel is under construction at the Hanjin Heavy Industries shipyard and is due for delivery in 2013 with subsequent deliveries following to 2016.

Propulsion configuration details show an unusual CODAD (combined operation diesel and diesel) with a TISO (twin input, single output) gearbox arrangement whereby the power from two MAN 12V28/33D STC engines are merged by a gearbox  with a single output shaft. There are two shafts propelling the ship with CP propellers. Each engine is rated at 5,460 kW at 1,000 rpm giving a total power of 21.8 MW. There is a 10 per cent overload on this rating for one hour in six hours. The engines will be installed in the ship with special elastic mountings to improve shock resistance and reduce noise and vibration .

The STC type suffix indicates sequential turbocharging providing higher torque over a wide rpm range. In addition, STC gives improved acceleration and lowers fuel consumption,
The engines are to be manufactured in Korea by MAN Diesel & Turbo licensee STX.

Caption: MAN Diesel & Turbo’s high speed diesel engine type MAN 12V28/33D
is rated at 5,460 kW at 1,000 rpm.
Image Credit: MAN Diesel & Turbo SE.