MAN Energy Solutions: Corporate History

MAN Energy Solutions SE designs the two-stroke low-speed marine engines that move most of the world’s deep-sea merchant tonnage. The company is the dominant licensor in that segment through its MAN B&W product line, and it builds and licenses four-stroke medium-speed engines for ships, gensets, and stationary power. It is a wholly owned subsidiary of Volkswagen AG, held directly within the Volkswagen Group rather than under the truck-and-bus holding Traton SE. The head office is in Augsburg, Germany, with the two-stroke engineering centre in Copenhagen, four-stroke work in Augsburg and Saint-Nazaire, and turbomachinery in Zurich and Oberhausen. Most of the physical engines are cut and assembled not by MAN but by licensed shipyard engine works in South Korea, Japan, and China.

This article traces that lineage from Rudolf Diesel’s first compression-ignition engine at Augsburg in the 1890s, through the 1980 absorption of Burmeister & Wain of Copenhagen, the move to electronic control and dual fuel, the 2018 rename, and the present ammonia and methanol roadmap. For the engineering of the cycle itself, see two-stroke marine diesel engine fundamentals. For the sizing maths used below, the companion tools include the G95ME-C9.5 performance calculator and the marine engine model decoder.

Augsburg origins and Rudolf Diesel

The Augsburg-Nuremberg lineage runs back to two separate machine works. Maschinenfabrik Augsburg was founded in 1840 and Maschinenfabrik Nurnberg in 1841. The two merged in 1898 to form Maschinenfabrik Augsburg-Nurnberg AG, the firm long known by its initials MAN. The Augsburg works had already done the thing the company still trades on.

Rudolf Diesel signed a development contract with Maschinenfabrik Augsburg in 1893, the same year his pamphlet on a rational heat engine appeared. The first test engine seized on its first firing attempt in August 1893. Diesel, the Augsburg engineers, and a parallel effort backed by Krupp worked the design through several rebuilds. The single-cylinder prototype ran under its own power and produced useful shaft work in February 1897, and a witnessed efficiency test that year recorded a brake thermal efficiency near 26 percent, far above the steam plant of the day. That number is the reason the compression-ignition engine took over heavy transport at all.

A modern two-stroke does the same energy accounting that Diesel measured in 1897: chemical energy in the fuel, useful work out, the ratio set by how completely the charge burns and how little heat escapes. The metric that captures it is brake thermal efficiency, computed from specific fuel oil consumption.

By the early twentieth century MAN had become one of the large European machinery groups, with diesel engines for stationary plant, locomotives, ships, and trucks, plus printing presses and turbomachinery. The first MAN two-stroke marine main engines went into production in the 1910s, and the firm supplied submarine and naval diesels in the same era. The marine two-stroke business grew across the interwar and postwar decades, but it shared the slow-speed segment with two rivals that mattered: Sulzer of Winterthur and Burmeister & Wain of Copenhagen. The consolidation that made MAN dominant came from buying one of them.

The corporate vehicle that carried the engine business changed names and owners many times. The Augsburg-Nuremberg firm was reorganised after both world wars, and its diesel division traded under several banners through the second half of the twentieth century, including MAN Diesel and, after the B&W absorption, MAN B&W Diesel. The constant across every reorganisation was the design authority for large engines and the Augsburg works, which is why the company can claim a continuous engineering line back to the 1897 prototype without claiming the same legal entity throughout.

Burmeister & Wain and the MAN B&W merger lineage

Burmeister & Wain was the principal Danish marine engine builder, with roots in a Copenhagen workshop of 1843 and a shipyard and engine works that became one of the two or three most-licensed two-stroke houses in the world. B&W built the motor ship Selandia in 1912, one of the first ocean-going diesel-powered cargo vessels, and through the twentieth century its two-stroke designs were copied under licence in yards across Europe and Asia. The full B&W story sits in its own article on Burmeister & Wain history.

The decisive move came in 1980, when MAN acquired the B&W marine diesel engine division to form the MAN B&W Diesel group. That merger folded together two of the three principal slow-speed lineages. It left Sulzer as the one independent slow-speed competitor of scale; Sulzer’s two-stroke business later passed to Wartsila and then in 2015 to WinGD, so the engineering history of Sulzer marine diesel engines is now the WinGD line. A separate Japanese two-stroke line, the Mitsubishi UEC engines, is the third surviving design family, now consolidated inside Japan Engine Corporation.

The naming convention is the practical legacy of 1980. The two-stroke product line is still branded MAN B&W. The B&W bore-stroke type codes carried straight across. So a buyer today still orders an “S90ME-C” or a “G80ME-GI,” and the letters trace to Copenhagen even though the design authority sits in MAN’s organisation.

The Copenhagen site matters beyond the brand. After 1980 MAN kept the two-stroke research, design, and the Diesel Research Centre test engines in Copenhagen, and that is where the ME electronic platform and the dual-fuel concepts were developed. The four-stroke work stayed in Augsburg and, after later acquisitions, in Saint-Nazaire. So the company runs two distinct engineering cultures under one roof: a Danish-rooted two-stroke house and a German-rooted four-stroke house, each with its own product line, type-code grammar, and licensee relationships. The merger did not blend them; it federated them.

It is worth being precise about what MAN did and did not buy. It bought the marine diesel engine division and its design rights and licensing business, the asset that set the global slow-speed standard. The wider Burmeister & Wain shipyard had a separate and difficult fate through the 1980s and 1990s as Danish merchant shipbuilding contracted. The engine design line is the part that survived inside MAN and that still earns money today.

The two-stroke low-speed business

The two-stroke low-speed engine is MAN’s core asset. These are the crosshead engines that turn the propeller shaft directly at 60 to 250 rpm, with bore sizes from 260 millimetres up to 950 millimetres and outputs from a few thousand kilowatts to roughly 80,000 kW at the top of the container-ship range. They burn heavy fuel oil, marine gas oil, or, in the dual-fuel variants, gas and liquid alternative fuels. The cycle and the scavenging arrangement are covered in two-stroke marine diesel engine fundamentals.

From MC to ME-C electronic control

The mechanically controlled generation carried the MC and MC-C type codes. A camshaft drove the fuel injection pumps and the exhaust valve actuation, with timing fixed by the cam profile. That generation ran the global fleet from the 1980s into the 2000s and is still in service in large numbers.

The change that defined the modern line was electronic control. MAN introduced the ME and ME-C engines in the early 2000s, replacing the camshaft with a hydraulic-electronic system: a high-pressure hydraulic power supply feeds electronically timed fuel injection and exhaust valve actuation, governed by an engine control unit. The first commercial ME engine entered service in 2003. Electronic timing let the engine hold lower specific fuel consumption across a wider load band, hit smoke and NOx limits more precisely, and run “part-load optimised” timing maps for slow steaming. The control architecture and the injection and valve actuation are described in the MAN B&W ME-C electronic control overview.

The difference between ME and ME-C is the size class. The full ME engines are the larger-bore types; the ME-C is the compact version for the mid and small bores, sharing the same control philosophy with a shorter, lighter structure. Within the ME-C the Mark number tracks the development steps: higher firing pressures, revised combustion, and the timing maps that cut fuel as emission tiers tightened. A Mark 9 and a Mark 10.5 of the same bore are different engines in their pressures and their fuel maps even though the type letters match.

The shift to electronics also changed how the engine is operated. A mechanically timed MC engine ran one fixed timing; the ME engine carries selectable maps, including a low-load tuning that holds combustion stable below 25 percent load, the band where slow-steaming container ships spent much of the 2010s. The engine control unit also logs cylinder-by-cylinder data, which is what condition-monitoring and the PrimeServ Assist service read to flag a worn injector or a leaking exhaust valve before it fails.

Engine type codes encode the design. A code like G95ME-C10.5 reads bore-stroke ratio (G for the longest-stroke “green ultra-long-stroke” group), bore in centimetres (95), the control type (ME-C), and a Mark number (10.5). The longer-stroke G and S types were brought out to let a ship turn a larger, slower, more efficient propeller, which cuts fuel per mile. The marine engine model decoder unpacks these strings.

The largest engines sit on the biggest container ships. The G95ME-C is the 950-millimetre-bore type used on ultra-large container vessels; in its longest-stroke marks it turns at roughly 80 rpm at full power, which lets the ship swing a propeller four metres or more larger in diameter than a comparable older engine and recover several percent of fuel at the same speed. A fourteen-cylinder G95ME-C is among the most powerful diesel prime movers ever built. The shaft power and fuel-rate accounting for the type is what the calculator works through.

The S90ME-C is the mid-large type for very large crude carriers, Suezmax and Aframax tankers, and capesize bulk carriers, at 900-millimetre bore. The S group sits one notch shorter in stroke than the G group; MAN’s progression from the K and S types into the longer-stroke G types over the 2000s and 2010s tracked the industry’s move to slow steaming, where a longer stroke and a slower, larger propeller pay back the most. A common feeder-container and handy-bulk choice is the 700-millimetre-bore G70ME-C, which pairs the long stroke with a smaller propeller envelope for handysize and supramax tonnage. Both follow the same per-cylinder power and fuel accounting as the G95, scaled by bore, stroke, and cylinder count, so the per-type calculators differ only in their default rating field.

The naming history is worth a line because owners still read it daily. The pre-electronic mechanically timed engines ran as K, S, and L bore-stroke groups with the MC and MC-C control suffix. The K group was the short-stroke high-speed-shaft type, the L group the long-stroke type of its day, and the S group the super-long-stroke type. When the longer “green ultra-long-stroke” G group arrived around 2010, it pushed the stroke-bore ratio past 4:1 on the largest types, which is why a modern G-type propeller turns so slowly.

Dual-fuel: ME-GI, ME-GA, ME-LGI, and ME-LGIM

The dual-fuel two-strokes are the line’s response to gas and to alternative fuels. The naming runs by injected fuel and injection concept.

The ME-GI is the high-pressure gas-injection engine, first ordered in 2012 and in service from 2015. It injects natural gas at roughly 300 bar near top dead centre and keeps the diesel combustion cycle, so it holds the efficiency of the base engine and shows low methane slip because the gas burns by diffusion rather than premixed. A pilot quantity of liquid fuel ignites the charge. The ME-GI runs on LNG with a marine gas oil or HFO pilot. A 600-millimetre-bore gas-injection type for medium tonnage is the S60ME-GI.

A large-bore gas-injection example for very large gas carriers and large container ships is the G80ME-GI, an 800-millimetre-bore type whose dual-fuel rating field matches the diesel-only G80ME-C closely, since the high-pressure concept keeps the base cycle. That parity is the selling point of the ME-GI: an owner buying gas capability does not give up the efficiency of the engine they would otherwise have bought.

The ME-GA, by contrast, is a low-pressure Otto-cycle gas engine that MAN brought to market later for the LNG-carrier trade, where the lower gas-supply pressure suits the cargo handling and reliquefaction arrangements. It accepts a higher methane-slip penalty than the ME-GI in exchange for a simpler, lower-pressure gas train. The two gas concepts coexist because the trade-off between methane slip and gas-supply cost lands differently for a container ship and an LNG carrier.

The liquid alternative fuels run under the ME-LGI family, where LGI stands for liquid gas injection. ME-LGIM is the methanol engine, which injects methanol at high pressure with a pilot of conventional fuel; the first ME-LGIM engines went into MR product tankers for Waterfront Shipping from 2016, and methanol has since spread to container newbuilds after the large 2021 ordering wave. The chemistry and class handling of methanol as a marine fuel sit in the methanol marine engines overview. The ME-LGIP variant burns LPG and was first ordered for very large gas carriers, with engines running from 2020, which let a VLGC burn its own cargo as fuel. An ethane-burning variant, ME-GIE, serves ethane carriers in the same way.

The common thread across the ME-GI, ME-LGIM, and ME-LGIP is that they keep the diesel-cycle combustion and add a second fuel system rather than converting the base engine to a premixed gas engine. That choice is why MAN’s dual-fuel two-strokes hold close to the efficiency and the low slip of the diesel-only engine and why a single platform can be offered across LNG, methanol, LPG, ethane, and ammonia by changing the fuel-supply system and the injector rather than the whole engine. The cost is a high-pressure fuel-supply system, which is more demanding to build and maintain than the low-pressure train of an Otto-cycle gas engine.

The economics of the fuel choice come down to grams of CO2 per kilowatt-hour at the engine, before any well-to-wake accounting; that tank-to-wake figure is set by the carbon content of the fuel and the engine’s specific fuel consumption, and it is the number the IMO carbon-intensity rules score.

The four-stroke medium-speed business

The four-stroke business comes from MAN’s own pre-merger engine line, not from B&W. These are trunk-piston engines running at 450 to 1,000 rpm for ship propulsion through a reduction gear, for diesel-electric power, for auxiliary gensets, and for stationary plant. The general engineering of the class is in medium-speed four-stroke marine engines.

The type code gives bore and stroke in centimetres. The current and recent line includes the 21/31, the 27/38, the 32/40, the 32/44CR, the 35/44, the 48/60, and the largest, the 51/60. The L or V prefix marks in-line or vee configuration; cylinder counts run from six in-line to eighteen in vee. The 32/44CR introduced common-rail injection to the medium-speed range, which is why the calculator and the rating maths treat it as its own type.

The 48/60 is the large medium-speed workhorse for diesel-electric propulsion on cruise ships, large ferries, and offshore vessels, and for stationary power. Its history and ratings sit in MAN 48/60 medium-speed engine. The common-rail 48/60CR uses the same per-cylinder rating accounting as the smaller types, scaled to its larger bore, and the 48/60CR performance calculator gives an indicative figure for a given cylinder count.

The dual-fuel four-strokes carry the DF suffix. The 51/60DF and 35/44DF run a lean-burn Otto gas cycle with a micro-pilot of liquid fuel, used for LNG-carrier and LNG-fuelled propulsion and gensets. Unlike the two-stroke ME-GI, the four-stroke DF engines are premixed Otto-cycle gas engines, so they accept lower gas-supply pressure but carry a higher methane-slip penalty at part load. That difference, high-pressure diffusion on the two-stroke versus low-pressure premixed on the four-stroke, is the same trade-off that separates the ME-GI from the ME-GA, and it is why the two engine classes suit different ship types.

The smaller end of the family, the 21/31 and the 32/40, serves auxiliary and genset duty across the merchant fleet, where a ship may carry three or four identical gensets for electrical load and redundancy. The common-rail 32/44CR has its own profile in MAN L32/44CR medium-speed engine; its common-rail injection holds injection pressure independent of engine speed, which improves part-load combustion and smoke. A separate high-speed line, the MAN 175D introduced in 2016, runs above 1,800 rpm for ferries, tugs, patrol craft, and yachts, and competes in a class MAN had largely left to others before; the D suffix marks the high-speed family rather than a bore-stroke code.

The four-stroke business also carries the stationary and power-plant work, which is a large part of MAN Energy Solutions outside shipping. The same 48/60 and 51/60 engines that drive ships also run as prime movers in diesel and dual-fuel power stations, often in island grids and in places where a gas turbine is the wrong size. That dual market is why the four-stroke line survived the marine downturns better than a pure ship-engine business would: when newbuild ship orders fell, the stationary and genset demand held part of the volume.

The licensing and licensee model

The defining feature of the two-stroke business is that MAN does not build most of its own engines. It licenses the designs to engine works owned by major shipbuilding groups, which manufacture, assemble, test, and deliver the engines to ships. MAN’s two-stroke revenue is principally licence fees, the supply of certain components, design and development, and global service, rather than direct manufacturing margin on each engine.

The licensee network concentrates in the three big shipbuilding nations. In South Korea, HHI-EMD, the Hyundai Heavy Industries Engine and Machinery Division, is the single largest producer of MAN B&W two-strokes by volume, and Hanwha Engine, the former Doosan Engine, is the other Korean licensee of scale. In Japan, Mitsui E&S DU and Kawasaki Heavy Industries build MAN B&W designs under licence, and Japan Engine Corporation builds MAN B&W types alongside its own UEC two-stroke line under cross-licence arrangements. In China, China State Shipbuilding Corporation’s marine power works build MAN B&W engines for the large domestic newbuild programme.

This model is why a single design office in Copenhagen can set the global standard for slow-speed propulsion. A type approved by MAN is then built to the same drawings in a dozen plants, which keeps spare-part interchangeability across the fleet and concentrates the design and emissions-certification burden in one place. It also means MAN’s market share is measured in licensed output, not its own factory output, and the licensees compete on price and delivery for the same approved designs.

The arrangement also shapes how a newbuild is bought. A shipowner orders a ship from a yard; the yard’s engine works builds the main engine to the MAN B&W type the owner specified, under licence; MAN earns a fee per engine plus the supply of certain proprietary components, and provides the project guide, the type approval, and the after-sales support. The same logic applies on the four-stroke side, though MAN builds a larger share of its own four-strokes directly than it does two-strokes. The split is partly historical: the two-stroke business grew up as a B&W licensing house, while the four-stroke business grew up as a MAN manufacturing line.

The aftermarket runs through the PrimeServ service network, with roughly 100 service stations worldwide supplying original-equipment parts, condition monitoring under the PrimeServ Assist banner, and overhaul services. For an engine type that may run 25 years, the parts and qualified-technician footprint is a large part of what locks an owner to the design. The retrofit business, covered below, runs through the same network, which is why MAN can offer a Tier III or an EPL upgrade on an engine a licensee built two decades earlier. A full directory of two-stroke and four-stroke OEMs and their licensees is held in the marine engine makers reference (article pending), which sits above this page in the cluster.

Turbochargers

MAN designs and builds its own marine turbochargers, which is unusual; most engine houses buy turbochargers from ABB Turbo Systems, now Accelleron, or from Mitsubishi Heavy Industries. The MAN axial-flow TCA series serves the large two-stroke engines, and the radial TCR series serves the smaller two-strokes and the four-strokes. Building the turbocharger in-house lets MAN match the compressor and turbine maps to a specific engine rating rather than fitting a stock unit, which matters most on the Tier III and EPL-limited builds where the air supply has to track a de-rated operating point.

Matching the turbocharger to the engine sets the air supply, and the air mass and its temperature move the fuel consumption and the achievable rating. Scavenge-air temperature is one of the practical knobs on a running engine: a colder, denser charge raises the air mass per stroke and lets the engine make rated power at a slightly lower fuel rate, which is why a fouled or undersized air cooler shows up first as a fuel-consumption penalty in the daily reports. The scavenge-air SFOC sensitivity calculator gives a first-order figure for that effect. For two-stroke engines MAN has also offered turbocharger cut-out, where one of several turbochargers is isolated at low load so the remaining units run at better efficiency, a measure that pairs with slow steaming on multi-turbocharger engines.

Ownership: from MAN AG to the Volkswagen Group

MAN AG traded as a public German industrial company through the twentieth century. Volkswagen AG built up its stake through the 2000s and reached majority control in 2011. The large-engine and turbomachinery business, then called MAN Diesel & Turbo, became a Volkswagen subsidiary.

The corporate reshape came in 2018 on two tracks. Volkswagen grouped its commercial-vehicle businesses, MAN Truck & Bus, Scania, and later Navistar, into the truck holding that listed as Traton SE in 2019. The MAN Truck & Bus business moved into Traton. The large-engine and turbomachinery business did not. It stayed under Volkswagen AG directly and was renamed MAN Energy Solutions in 2018, with the new name chosen to mark the move from a pure diesel-and-turbo supplier toward power-conversion and energy-transition products: methanol and ammonia engines, large heat pumps, electrolysers, and grid-scale energy storage. So the marine engine company and the truck company share the MAN name and a common ancestor but sit in different parts of the Volkswagen Group, and neither owns the other.

The rename was more than branding. MAN Diesel & Turbo had been organised around two product worlds, marine and power-plant engines plus turbomachinery. MAN Energy Solutions added a third axis, the decarbonisation businesses, and reorganised its public message around the energy transition rather than around diesel. The marine engine line did not change overnight, but the priority order did: the dual-fuel and alternative-fuel two-strokes moved from a niche offering to the headline product, and the company began to describe itself as a supplier of the technology that lets shipping and industry cut carbon, not just as the world’s largest builder of ship engines.

The ownership detail matters for anyone tracing liability or warranty up the chain. The legal parent is Volkswagen AG, the engine company is MAN Energy Solutions SE, and the entity is distinct from MAN SE, the historical listed holding, and from Traton SE. Confusing the marine engine company with the truck company, or with the old MAN SE holding, is a common error in trade reporting; they are related by history and name but are separate businesses today.

Decarbonisation roadmap

MAN’s public roadmap aligns the two-stroke line to the IMO greenhouse-gas trajectory by offering engines that burn carbon-light or carbon-free fuels. The two lead fuels are methanol and ammonia.

Methanol came first in service, through the ME-LGIM described above, because methanol is a liquid at ambient conditions and the high-pressure injection concept was provable on the running MR-tanker fleet from 2016. The container-ship sector then placed large methanol newbuild orders from 2021 onward, which pulled ME-LGIM into the large-bore range. The fuel handling and combustion are covered in the methanol marine engines overview.

Ammonia is the harder fuel and the bigger prize, because it carries no carbon. MAN’s ammonia two-stroke is the ME-LGIA, a high-pressure liquid-injection engine that ignites ammonia with a pilot of conventional fuel and is designed to limit unburned ammonia and the nitrous-oxide slip that would otherwise undo the climate benefit. The first ammonia-engine orders were placed in the early 2020s, with the technology and the safety case described in the ammonia marine engines overview. Ammonia is toxic and needs a different gas-train and safety design than methanol or LNG, which is why the engine and the ship systems are being type-approved together with the class societies rather than retrofitted casually.

Two slip problems make ammonia harder than methanol. Unburned ammonia in the exhaust is toxic and needs an after-treatment catalyst to clean up, and nitrous oxide, which forms in small amounts in ammonia combustion, is a greenhouse gas roughly 270 times as potent as CO2 per unit mass, so even a low N2O slip can erode the carbon saving. MAN’s high-pressure diffusion-combustion concept is chosen partly to hold both slips low, since premixed ammonia combustion tends to produce more of both. The engine is one part of the answer; the ship’s ammonia storage, the double-walled piping, and the gas-detection and purge systems are the rest, and class societies treat the whole arrangement as a single safety case.

The roadmap is sequenced by fuel readiness, not by preference. Methanol leads because it is a manageable liquid and the engine was provable on a small tanker fleet; ammonia follows as the carbon-free target once the toxicity and slip controls are demonstrated; LNG and the ME-GI sit alongside as the lower-carbon bridge already running in large numbers. MAN markets all of them on one two-stroke platform, which is the commercial point of keeping the diesel-cycle base engine common across fuels.

The reason fuel and speed dominate the emissions arithmetic is the cube law: the power a hull needs rises with roughly the cube of speed, so a small speed cut yields a large fuel cut, and the engine is sized and de-rated around that curve.

Aftersales, retrofit, and EEXI compliance

The installed base is the other half of the decarbonisation problem, because most of the engines that will run through the 2030s already exist. MAN’s retrofit programmes target both NOx and the energy-efficiency rules.

For NOx Tier III, which MARPOL Annex VI Regulation 13 sets for ships built from 2016 operating in designated emission control areas, MAN offers two routes. Exhaust gas recirculation routes part of the exhaust back into the scavenge air to cut peak combustion temperature and so cut NOx formation in the cylinder; the two-stroke EGR arrangement is covered in EGR retrofit on two-stroke engines. Selective catalytic reduction injects urea into the exhaust upstream of a catalyst to reduce NOx to nitrogen and water, the route described in SCR retrofit on two-stroke engines. The choice of system and the layout for new and existing engines is the subject of Tier III compliant two-stroke engines.

For energy efficiency, the relevant levers are engine power limitation and shaft power limitation, the EPL and ShaPoLi measures used to meet the Energy Efficiency Existing Ship Index that took effect for existing ships in 2023. An owner caps the engine’s maximum continuous rating, which lowers the attained index at the cost of available power, and MAN supplies the limiter hardware and the documentation the class survey needs. The index itself and the limiter mechanics sit in what is EEXI, and the design-stage index for newbuildings is in what is EEDI. MAN’s role in a retrofit is to certify that the limited engine still runs safely at the capped rating and to supply the verified power curve the surveyor signs against.

The two limiter routes differ in how they are sealed and overridden. EPL caps the engine through the engine control system, with a sealed limit the crew cannot raise in normal operation; ShaPoLi caps the shaft power through a power meter on the shaft and a limiter on the propulsion command. Both must allow a documented override for safety, where a master can call full power in heavy weather or to avoid a casualty, with the override logged. The reason this matters to MAN is that the certified power curve and the override logic are part of the engine documentation, not just the ship’s; the maker has to confirm the engine behaves correctly at the limited rating and through the override.

EPL also interacts with the engine’s tuning. A two-stroke optimised for a high original rating may run inefficiently at a hard cap well below it, so MAN offers part-load and low-load tuning packages alongside the limiter, so the de-rated engine sits near a good point on its fuel map rather than at a penalised one. That tuning work is the same electronic-control capability that the ME platform brought in the 2000s, now turned to a regulatory purpose. An owner choosing between EPL, ShaPoLi, and a deeper de-rate is trading available power, fuel efficiency at the new operating point, and the cost of the retrofit, and MAN’s project work is to put numbers against each option for a specific ship.

The carbon-intensity rules add a running dimension on top of the one-time EEXI cap. The operational carbon intensity an owner must report each year depends on the fuel burned over the voyages actually sailed, which loops back to the speed-power cube law and the fuel choice. A ship that meets its EEXI on paper through an EPL cap still has to keep its annual operating intensity inside the tightening trajectory, which is why slow steaming, hull cleaning, and fuel switching matter alongside the engine hardware. The engine maker supplies the efficient hardware; the operator supplies the operating profile that turns it into a reported number.

Limitations

A few practitioner caveats apply to anything in this article.

Type codes change with Mark numbers and emission tiers, and a single bore-stroke type covers many ratings. The “G95ME-C” sold in 2015 is not identical to one sold in 2024; the Mark number, the timing maps, and the Tier III hardware differ. Always read the engine’s own project guide and shop-test record for a specific build, not a generic type description.

Output figures are rating-band dependent. A two-stroke is specified by its layout field, the set of MCR points the type can be optimised to, not by one number. The “roughly 80,000 kW” top end quoted here is the order-of-magnitude ceiling of the largest container-ship engines, not a fixed maximum; the actual contract MCR for a ship is chosen inside the layout diagram. Use the per-type calculators for an indicative figure and the project guide for a contractual one.

Licensee shares shift. The statement that one builder is “largest” reflects multi-year volume, not a fixed ranking; Korean, Japanese, and Chinese output moves with the newbuild order book and with consolidation among the shipbuilding groups. Treat the licensee list as the set of approved builders, not a league table.

Dual-fuel performance depends on the fuel and the duty. Methane slip, ammonia slip, and nitrous-oxide formation are sensitive to load, to the injection concept (ME-GI versus ME-GA, for instance), and to the after-treatment fitted. A single “low slip” claim does not carry across the whole load range; the figures that matter are the ones from the type-approval test at the relevant operating points.

The formula cards on this page are sizing and screening tools. They give first-order figures for power, fuel rate, and emissions and are not a substitute for the maker’s project guide, the shop test, or the classification society’s verified documentation when a contract or a survey depends on the number.

See also

• Two-stroke marine diesel engine fundamentals
• MAN B&W ME-C electronic control overview
• Burmeister & Wain: 1843 to 1980 history
• Medium-speed four-stroke marine engines
• MAN 48/60 medium-speed engine
• MAN L32/44CR medium-speed engine
• MAN 32/40 medium-speed engine
• MAN L21/31 medium-speed engine
• HHI-EMD: Hyundai Engine and Machinery Division
• Hanwha Engine corporate history
• Mitsui E&S DU marine engines
• Kawasaki Heavy Industries marine engines
• Mitsubishi UEC two-stroke engines
• Sulzer marine diesel engines: foundational history
• WinGD corporate history
• Methanol marine engines overview
• Ammonia marine engines overview
• SCR retrofit on two-stroke engines
• EGR retrofit on two-stroke engines
• Tier III compliant two-stroke engines
• What is EEXI
• What is EEDI
• Marine engine model decoder