SEMT-Pielstick Marine Diesel Engines

Background

SEMT-Pielstick (Societe d’Etudes de Machines Thermiques) was the French medium-speed marine diesel engine design house behind two engine families that powered warships, ferries, and merchant ships across more than half a century. The company designed the PA series and the PC series, licensed both widely, and built almost nothing in volume itself. That design-and-licence model put Pielstick engines into navies and shipyards on six continents while the firm stayed small. MAN B&W Diesel bought the business outright in 2006, and the Pielstick brand was wound down afterward, its product responsibilities folded into what is now MAN Energy Solutions.

The Pielstick story sits at the intersection of three threads in twentieth-century marine engineering. The first is cross-border engineering migration: Gustav Pielstick was a German diesel designer who moved to France in the late 1940s. The second is the national-champion industrial policy of post-war France, which consolidated a fragmented engine industry under one technical organization. The third is the design-house-plus-licensee commercial model, now standard across slow-speed marine engines, where one firm holds the intellectual property and shipyards in Korea, Japan, and China cut the metal.

This article covers the founding, the PA and PC engine families with their type designations, the licensing network, the naval and merchant applications, and the corporate path from independent French design house into MAN. It does not invent power or fuel-consumption figures: where a number appears, it is a published specification or a documented installation, not an estimate. For the broader four-stroke context, see medium-speed four-stroke marine engines and four-stroke marine diesel engine fundamentals.

Gustav Pielstick and the founding

Gustav Pielstick (1890 to 1961) trained as a mechanical engineer in Germany and joined MAN at Augsburg, the firm that had built the first commercial diesel engines under Rudolf Diesel’s patents. Through the 1920s and 1930s Pielstick worked on medium-speed and slow-speed diesel development at Augsburg, and he became MAN’s chief diesel designer. His naval diesel work in that period covered high-power installations, the kind of engineering that later made him the obvious technical lead for a French naval-engine programme.

After the Second World War, France faced a problem. Its marine engine industry was split across several firms, and the country leaned on foreign designs, Swiss and German in particular, for ship propulsion. The Ministry of Industrial Production wanted a domestic medium-speed diesel design capability that would not depend on licences bought from competitors abroad. The answer was to create one technical organization and hire the best available designer to run it.

That organization was SEMT, the Societe d’Etudes de Machines Thermiques, set up in the late 1940s as a design bureau rather than a volume manufacturer. The arrangement brought together French industrial and shipbuilding interests, including Schneider et Cie of Le Creusot and the shipbuilders at Saint-Nazaire, under a single engineering roof. SEMT itself would draw the engines; French and licensed builders would manufacture them.

Pielstick moved to France with a small group of MAN colleagues to take the technical director post. The recruitment was politically sensitive given how close it came to the war, but the strategic priority on rebuilding French engine capability won out. The hyphenated name SEMT-Pielstick recorded the split: SEMT was the corporate entity, Pielstick the technical lead. Over time the engines were branded “Pielstick” alone, and that is the name marine engineers still use for the PA and PC families today.

The design-bureau structure shaped everything that followed. Because SEMT did not need to fill its own large foundry and machine shops, it could sell licences to any builder willing to pay, including builders who would otherwise have been customers of MAN or Sulzer. That structural choice, made at the founding, is the reason Pielstick engines turn up in so many navies that had no other connection to French industry.

There’s a second consequence of the design-bureau model that is easy to miss. A firm that builds its own engines carries the cost of a factory whether orders come in or not, so it has to chase volume to keep the shop busy. A firm that only draws engines and sells licences has almost no fixed manufacturing cost, so it can survive on a thin order book and a stream of royalties. That is why SEMT-Pielstick stayed independent for nearly sixty years while its installed base grew across the world: the business did not need French shipyard volume to pay its way. The licensees carried the capital risk of the foundries and machine shops; SEMT carried the drawings and the brand. When the medium-speed market consolidated in the 1980s and 1990s, the licence income that had kept the bureau alive was exactly the asset that made it worth buying.

The founding-era choice of medium-speed four-stroke architecture, rather than the slow-speed two-stroke route that Burmeister and Wain and Sulzer took for large merchant ships, also fixed Pielstick’s market. A four-stroke medium-speed engine runs faster, fits a smaller hull volume per unit power, and needs a reduction gearbox between the engine and the propeller. That makes it the natural choice for warships, ferries, and offshore craft, and the wrong choice for a large bulk carrier or tanker where a direct-drive slow-speed two-stroke wins on fuel economy. Pielstick never tried to compete in the slow-speed cargo market; the PA and PC families lived in the medium-speed niche from the first prototype to the last delivery.

The PC engine family

The PC series was Pielstick’s medium and low-medium-speed line: larger bore, lower speed, built for sustained heavy-fuel running on merchant ships and for main propulsion on warships. The family grew across four decades through a sequence of bore increases and per-cylinder power gains, and the PC2 generation became one of the most-installed medium-speed designs in the world.

PC1 and PC2

The first series was the PC1, with prototypes running in the early 1950s. Early PC1 work used a bore near 400 mm and a twin-crankshaft prototype layout that was dropped before series production. The PC1 proved the architecture but sold in small numbers. It was the PC2, launched in the mid-1960s, that turned the design into a commercial product. The PC2 used a single crankshaft, a 400 mm bore, and both in-line and V cylinder arrangements, with the V layouts dominating at higher cylinder counts. Operating speed sat near 500 to 520 rpm.

The PC2 and its derivatives became the mainstream Pielstick product. The line ran through a series of evolutionary variants that kept the 400 mm bore while raising per-cylinder power and refining the combustion, piston, and turbocharging systems. The PC2.5, launched in the early 1970s, added a substantial power increase over the earlier PC2.2 through a revised two-piece piston and improved cooling, still at 400 mm bore. The PC2.6, introduced in the early 1980s, became the long-running naval variant, holding the 400 mm bore and roughly 500 mm stroke while updating the fuel injection, turbocharging, and control systems.

The brake mean effective pressure is the single figure that tracks this evolution most directly: each PC2 variant raised cylinder output mainly by pushing more air through the engine and burning more fuel per cycle, which shows up as a higher BMEP at a near-constant bore and speed.

Because bore, stroke, and rated speed stayed fixed across the PC2 generations, the mean piston speed barely moved while output climbed. That is the signature of a design family that gains power through charging and combustion refinement rather than through a faster-running or larger engine, and it is why a 1960s PC2.2 and a 1980s PC2.6 share so many parts and so much service know-how.

The intermediate PC2 variants filled in the steps between the launch engine and the naval workhorse. The PC2.2, available from the early 1960s, set the early production standard at 400 mm bore and the 500 to 520 rpm speed band. The PC2.3, from the early 1970s, kept the bore and lifted the cylinder output through combustion and charging changes within the same envelope. The PC2.5 followed with a larger jump in power, and the PC2.6 closed the line as the variant most navies specify today. Each step reused the crankcase, bearings, and much of the running gear of the one before it, which is the whole point of a long-lived design family: an operator who trained fitters on a PC2.2 in 1965 could still use most of that knowledge on a PC2.6 in 1985. The STC suffix on the later naval engines marks the sequential turbocharging system that gives good response and low fuel consumption across the load range a warship actually uses, where most running is at part load rather than at the rated point.

The turbocharging is where the per-cylinder power came from across the PC2 generations. A naturally aspirated diesel is limited by how much air it can draw in on the intake stroke; a turbocharged diesel forces more air in, burns more fuel per cycle, and produces more power from the same swept volume. The PC2 line climbed from its 1960s output to its 1980s output mainly by raising the charge-air pressure and managing the resulting cylinder pressures and temperatures with better pistons, valves, and cooling. The sequential turbocharging on the STC engines added a second stage that cuts in as load rises, so the engine breathes well at low load as well as high, which is the load profile a warship spends most of its life in.

PC3 and PC4

The PC3, launched in the early 1970s, took the bore up to 480 mm in a redesign aimed at higher per-cylinder power. It sold less well than the PC2 derivatives, partly because the market was moving toward the larger-bore approach that the PC4 would soon cover. The PC4, introduced in the late 1970s, scaled the architecture up to a 570 mm bore and sat at the boundary between medium-speed and low-medium-speed running, with rated speeds in the 400 to 500 rpm band. The long-stroke PC4.2B variant, available from the mid-1980s, was among the most powerful medium-speed engines of its day in large V configurations.

Across the PC family the bore range ran from roughly 400 mm on the PC2 to 570 mm on the PC4, with outputs that climbed from a few thousand kilowatts on small in-line PC2 engines to the high-power large-V PC4 machines. The exact rating of any given unit depends on the variant, the cylinder count, and the turbocharging package, so a buyer reads the type plate rather than the family name. The marine engine model decoder at /calculators/engine-model-decoder breaks down how Pielstick type designations encode bore, layout, and cylinder count.

Reading a Pielstick type designation follows a consistent grammar. A label like 16PC2.5 V400 says the engine has 16 cylinders, belongs to the PC2.5 variant, sits in a V arrangement, and has a 400 mm bore. A label like 12PA6 V280 says 12 cylinders, PA6 variant, V arrangement, 280 mm bore. The cylinder count drives the total power for a given variant, so the same PC2.5 design appears as small in-line engines for gensets and large 16-cylinder and 18-cylinder V engines for main propulsion. That is how one design covers a power range of several times from bottom to top: the engineering is in the cylinder, and the ship buyer picks how many cylinders the application needs. The PC4 sat at the top of the medium-speed market by power, and its long-stroke variants pushed the per-cylinder output to the limit of what a 570 mm-bore four-stroke could deliver at the time.

The PC3’s commercial fate is worth a note because it shows how a sound engine can still miss the market. The 480 mm bore was a real step up in capability over the 400 mm PC2, but it landed in a window where buyers who wanted more power than a PC2 increasingly wanted the larger jump that the PC4 would soon offer, while buyers happy with PC2-class power had no reason to move. The PC3 ended up between two stronger sellers and never built the volume of either. Pielstick learned the lesson, and the later development effort concentrated on extending the PC2 line through the PC2.5 and PC2.6 and on the high-power PC4, rather than on filling the gap the PC3 had tried to occupy.

The PA engine family

The PA series was Pielstick’s smaller-bore, higher-speed line, sitting at the fast end of the medium-speed range and into high-speed territory. Smaller bore and higher rotational speed gave the PA engines a high specific output for their size, which is what naval architects want for frigates and fast craft where deck space and weight matter more than fuel economy. The PA series ran from the 1960s onward.

The family covered several bore sizes. The smaller PA4 used a bore around 185 mm; the larger PA6 used a bore near 280 mm. The PA6 was the one that mattered most for warships. It came in a sequence of developed variants, including the PA6 V280 and the PA6 STC, that raised output and efficiency over the production run. The PA6 became the dominant medium-speed prime mover on French frigates and turned up on European and export warships, smaller commercial vessels, and offshore craft. Rated speeds for the PA line ran higher than the PC engines, into the four-figure rpm range on the smaller variants.

The two families divided the market cleanly. The PC engines, with their larger bore and lower speed, suited heavy-fuel merchant running and warship main propulsion where fuel cost over a long service life mattered. The PA engines, smaller and faster, suited warships and fast craft that needed power in a tight envelope and ran on distillate fuel. For where these sit against other builders, see medium-speed four-stroke marine engines and the broader marine diesel engine overview.

The PA6 deserves separate treatment because it carried the French Navy’s frigate propulsion for decades and set the pattern for high-speed naval diesel design in Europe. At a 280 mm bore and rated speeds well above the PC engines, the PA6 traded fuel economy for power density: a frigate does not steam economically across an ocean the way a bulk carrier does, so it can afford a thirstier engine in exchange for a smaller, lighter installation that leaves more hull volume for weapons, sensors, and fuel. The developed PA6 variants, including the V280 and the STC versions, raised output and improved part-load economy over the production run without changing the basic bore. Naval staffs valued the PA6 for the same reasons the PC2 worked on warships: proven reliability, the licence option for domestic build, and shock resistance in militarized form, but with the higher specific output that a frigate’s machinery space demands.

The smaller PA4, at roughly 185 mm bore, served the bottom of the range: auxiliary gensets, small craft, and applications where a compact high-speed engine fitted better than a larger medium-speed unit. Between the PA4 and PA6, Pielstick covered the high-speed and fast-medium-speed band that the PC engines were too large and slow to serve, so the two families together spanned from small genset power to the high-power main propulsion of an amphibious transport dock. Few engine designers of the period held that full a range under one set of drawings.

The licensing model

The licensing network was the engine of Pielstick’s reach. Because SEMT was a design bureau that did not need to defend its own large factory, it sold manufacturing licences to builders around the world. Those licensees cast and machined the engines under Pielstick drawings, paid royalties, and sold into their own home markets. The result was an installed base far larger than French production alone could have built.

Fairbanks Morse in the United States built Pielstick PC engines under licence, and that arrangement put Pielstick designs into US Navy and US-flag service. Fairbanks Morse remains an active US engine builder today and has no dedicated node on this site; that gap is flagged below. In Japan, Kawasaki Heavy Industries and other Japanese builders held Pielstick licences for Japanese vessels. Mitsubishi Heavy Industries built Pielstick designs under licence in Japan as well. German, Italian, Chinese, Korean, and Indian builders took licences too, including Fincantieri Grandi Motori Trieste in Italy for Italian naval and commercial work, and Indian builders for Indian Navy programmes.

The licence model had a second effect beyond reach. It made Pielstick designs attractive to navies that wanted domestic production rather than imported engines. A government buying frigates could license the engine, build it in a home yard, and keep the industrial work and the spares supply inside its own borders. That political-industrial logic, not just engineering merit, explains a good part of the PC and PA naval installed base. The same design-house-plus-licensee split is now the norm in slow-speed two-stroke engines, where MAN Energy Solutions and WinGD hold the designs and Asian yards do the manufacturing. See marine engine makers for how that pattern spread across the industry.

Naval applications

Naval propulsion was Pielstick’s most important market by value, and the PA and PC families split the naval work between them along the same lines as the commercial market: PC engines for larger ships and main propulsion, PA engines for frigates and fast craft.

The French Marine Nationale was the home customer and ran Pielstick engines on surface combatants for decades. The La Fayette-class frigates use PA6-series engines in a combined-diesel-and-diesel arrangement, with multiple 12-cylinder V280 STC units per ship driving the shafts. French frigates, corvettes, and patrol vessels across several generations carried PA6 main propulsion, and the engine became the standard medium-speed prime mover for the French fleet.

The largest single Pielstick naval program in the United States is the San Antonio-class amphibious transport dock, the LPD-17 class, which uses four 16-cylinder PC2.5 STC engines per ship. That installation, built around Fairbanks Morse licensed production, is one of the most extensive Pielstick naval fits anywhere. US auxiliary and support ships carried Pielstick engines as well, through the same Fairbanks Morse licence.

Beyond France and the United States, Pielstick PC and PA engines powered warships in many navies, including export frigates and corvettes built in European yards with Pielstick engines for buyers in the Middle East, North Africa, South Asia, and Latin America. Saudi and Moroccan frigate programs used Pielstick propulsion, and Indian, Italian, and other fleets ran licensed or supplied Pielstick engines across multiple ship classes. The breadth of the naval installed base is one of the largest among medium-speed marine engine builders.

The combined-diesel-and-diesel arrangement on the La Fayette frigates is worth explaining because it is the standard way navies use medium-speed diesels on a surface combatant. Two engines drive each shaft through a gearbox; one engine runs the shaft for economical cruising, and both engines couple in for higher speed. That lets a frigate cruise efficiently on half its installed power and still reach its top speed when both engines are online, without the fuel penalty of running large engines lightly loaded all the time. The PA6 V280 STC’s part-load economy made it well suited to this duty, since a frigate spends far more hours cruising on one engine per shaft than sprinting on both. The same logic, scaled up, put four PC2.5 STC engines into each San Antonio-class LPD, where the amphibious mission calls for sustained moderate-speed running rather than the high-speed dash a destroyer needs.

Several engineering traits made Pielstick attractive for warships. The 400 mm-bore PC engines offered high power density, useful output per cubic meter of machinery space, which is at a premium on a warship. The designs were proven through decades of merchant service before navies adopted them, so reliability was demonstrated rather than promised. The multi-fuel capability let warships run on the distillate or residual fuels available in a given theater. The licence availability, covered above, let navies build at home. And militarized variants demonstrated resistance to underwater-explosion shock, a requirement no merchant engine has to meet.

Medium-speed diesels sit in a specific niche against the alternatives. Against marine gas turbines, they offer better part-load fuel economy at lower acquisition cost, at the price of more machinery weight and volume. Against slow-speed two-strokes, they offer better power density at the smaller scales that warships and fast ferries need, at the price of higher rated speed and more frequent maintenance. Naval architects still specify medium-speed diesels for amphibious, auxiliary, and lower-speed combatant roles for those reasons. For the entirely different propulsion logic of nuclear-powered warships, see naval nuclear propulsion overview.

Merchant and offshore applications

The merchant side of the Pielstick business ran on the PC engines and, for auxiliary power, the PA engines. Cross-Channel and Mediterranean ferries through the 1960s, 1970s, and 1980s carried Pielstick PC main propulsion in large numbers; the high power density that suited warships also suited ferries that needed to fit machinery into a vehicle-deck hull. Mid-sized cargo vessels, offshore supply ships, and some specialty cruise ships used PC engines for main propulsion.

PA engines served as auxiliary gensets on cargo ships and tankers, and as main engines on smaller and faster commercial craft and offshore vessels. The split mirrored the naval one: the larger, slower PC for heavy-fuel main propulsion, the smaller, faster PA for auxiliary duty and high-speed roles. Industrial installations, including power for offshore platforms and drilling units, used Pielstick engines as well.

Fuel economy is where the merchant operator lived, and the specific fuel oil consumption is the figure that decides the voyage cost. Brake thermal efficiency is just the same information stated as a fraction of the fuel’s energy that reaches the crankshaft, which is why operators and surveyors convert between the two.

The published SFOC of a marine diesel is quoted at reference air and seawater conditions, and the real figure drifts with charge-air temperature, ambient conditions, fuel quality, and engine condition. A warship or ferry running in the tropics sees a higher SFOC than the test-bed number, which matters for endurance and bunker planning.

Corporate path into MAN

Pielstick’s corporate history runs from the post-war French design bureau, through ownership inside the Alsthom industrial group, into joint German ownership, and finally into MAN. SEMT-Pielstick became part of the Alsthom group and then GEC Alsthom after the 1989 merger of the French and British heavy-engineering interests, which inherited the engine business through that corporate restructuring.

In 1988 the engine business was acquired from the Alsthom side by MAN and MTU Friedrichshafen as joint partners, a structure that reflected the German marine-engine industry’s shared interest in adding the Pielstick designs to its portfolio. MAN raised its stake later, leaving MTU with a residual minority holding. In 2006 MAN B&W Diesel bought out MTU’s remaining stake, making SEMT-Pielstick a wholly owned MAN subsidiary. That 2006 acquisition ended more than half a century of independent corporate identity and put the PA and PC product responsibilities inside MAN.

After 2006 the Pielstick brand was wound down. MAN consolidated its product line, kept Pielstick as a service portfolio for the large installed base, and directed new orders toward its own four-stroke designs rather than continuing volume production of Pielstick-branded engines. New naval and merchant orders went to the MAN four-stroke programme, while the PA and PC fleets stayed in service supported through MAN’s aftermarket organization.

The corporate parent kept changing names around the Pielstick service line. MAN Diesel and MAN Turbo merged into MAN Diesel and Turbo in 2010, which became MAN Energy Solutions in 2018. Through each rebrand the SEMT-Pielstick service portfolio survived as a branded line for legacy support. The pattern is the one that took Sulzer, Burmeister and Wain as an independent, and other twentieth-century engine brands into larger competitors, and it left MAN Energy Solutions holding the dominant share of the world medium-speed and slow-speed engine designs. For that corporate lineage, see MAN Energy Solutions corporate history. The MaK medium-speed line followed a parallel route into the same broad consolidation; see MaK Maschinenbau Kiel marine engines.

Service and support today

Pielstick PA and PC engines remain in active service worldwide, and the spares-and-service business is sustainable on the size of the installed base alone. MAN Energy Solutions supports the engines through its SEMT-Pielstick service portfolio, maintaining the original technical documentation and supplying parts. Licensees in regions with large Pielstick fleets, including Indian builders for Indian Navy work, support locally built and operated engines. Authorized service specialists cover regions with significant fleets.

New-build production of Pielstick-branded engines has largely stopped, with one practical exception: PC-series engines are still made to order for specific naval clients where a navy’s existing fleet standardization makes a new Pielstick unit cheaper to support than a switch to a different engine. For most new orders, though, the buyer takes a current MAN four-stroke design rather than a Pielstick.

Emissions and regulatory context

Pielstick engines in service must meet the same emission rules as any marine diesel of their vintage and operating area. The governing instrument is MARPOL Annex VI, which sets nitrogen-oxide limits under Regulation 13 in tiers keyed to the keel-laying date of the ship, and sulfur limits under Regulation 14. An engine built before the relevant tier date is held to the tier in force when its ship was laid down, so older Pielstick installations sit at Tier I or Tier II rather than the Tier III limits that apply to recent newbuildings operating in designated emission control areas.

Carbon-dioxide output is fixed by the fuel burned, because the carbon in the fuel oxidizes to CO2 regardless of engine design, so the CO2 per kilowatt-hour follows directly from the SFOC and the fuel’s carbon factor.

Class societies survey these engines under their machinery rules; DNV, Lloyd’s Register, ABS, and Bureau Veritas all maintain the rule sets that govern medium-speed diesel installation, survey, and certification. The emission certification, the NOx Technical Code engine file, and the periodic class surveys are what keep a 1980s PC2.6 or PA6 legally in service today.

Engineering legacy

The PC2’s 400 mm bore at 500 to 520 rpm became a reference point for medium-speed engines through the 1970s, 1980s, and 1990s. Competing designs from other builders clustered in the bore range that the PC2 helped establish, and the medium-speed market settled around the size and speed band that Pielstick had proven commercially viable.

The licensing model was the deeper legacy. Pielstick showed that a design house could separate the intellectual property from the manufacturing and still build a large installed base, capturing royalty income without the capital cost of a global factory network. That model is now standard in slow-speed two-stroke engines and common in medium-speed, where the design owner sells licences to builders in Korea, Japan, and China. The structure that let a small French bureau put engines into dozens of navies is the structure that now governs most of the world’s large marine engine production.

The naval legacy is concrete. The US Navy’s choice of the PC2.5 STC for the San Antonio-class LPD, and the French Marine Nationale’s long use of the PA6 on its frigates, demonstrated the medium-speed diesel’s place in modern naval propulsion against gas turbines and two-strokes. The propulsion power a displacement hull needs rises roughly with the cube of its speed, so a frigate that wants a few extra knots needs a large jump in installed power; that cube relationship is why navies fit multiple medium-speed diesels in a combined arrangement rather than one engine sized for top speed, and it is the same relationship a ship operator uses to estimate how fuel burn changes with speed. The /calculators/engine-cube-law-fuel tool works that relationship for a given hull and speed pair.

The medium-speed diesel also held its naval position because of what it does at part load. A gas turbine is efficient near its rated power and wasteful when throttled back, while a medium-speed diesel keeps a usable fuel economy across most of its load range. A warship spends the bulk of its sea time at cruise, well below full power, so the diesel’s part-load behavior matters more than its peak. That single fact, more than any other, kept Pielstick engines in frigates, amphibious ships, and auxiliaries long after gas turbines took over the high-speed combatant role, and it is why the PA6 and PC2 fleets are still in service decades after their ships were laid down.

The SEMT-Pielstick design archives are held within MAN Energy Solutions’ corporate records, with some material in French maritime engineering archives. The engineering knowledge did not vanish with the brand: it fed the medium-speed expertise inside the company that bought it, and the PA and PC running gear still informs how MAN supports and re-rates the legacy fleet.

Limitations

This article reports type designations, bore sizes, speed bands, and documented installations from published specifications and the successor manufacturer’s records. It does not state per-cylinder power or fuel-consumption figures for specific variants, because those numbers depend on the exact turbocharging package, cylinder count, and rating point of each unit, and quoting a single figure for a family that ran for decades would mislead more than it informs. Read the engine type plate and the manufacturer’s project guide for the rating of any given installation.

The corporate dates given here describe the main ownership transfers: joint MAN and MTU acquisition in 1988, MAN’s later stake increase, and the 2006 buyout that made SEMT-Pielstick a wholly owned MAN subsidiary. Intermediate holding-company restructurings inside the Alsthom and GEC Alsthom group are summarized rather than itemized. The naval installations listed are documented public fits; this is not a complete fleet list, and individual ships within a class can carry different engine marks after refits and re-engining.

The emission discussion states the MARPOL Annex VI framework and the principle that NOx tiers attach to a ship’s keel-laying date. It does not certify any specific engine to any specific tier; that determination belongs to the engine’s NOx Technical Code file and its flag and class records. Operators and surveyors should work from the actual certificate, not from the general rule, for any compliance decision.

Related calculators

• BMEP Calculator
• Mean Piston Speed Calculator
• Brake Thermal Efficiency from SFOC
• SFOC Sensitivity to Air Temperature
• CO2 Emission per kWh
• Marine Engine Model Decoder
• Yard: Chantiers de l’Atlantique

See also

• MAN Energy Solutions: Corporate History
• MaK Maschinenbau Kiel Marine Engines
• Medium-Speed Four-Stroke Marine Engines
• Four-Stroke Marine Diesel Engine Fundamentals
• Marine Diesel Engine
• Naval Nuclear Propulsion Overview
• Marine Engine Makers