Marine Machinery Catalogue

Wärtsilä

The Wärtsilä 46DF is a dual-fuel, four-stroke, medium-speed marine engine, one of the best-known engines in the class of machinery that can run either on natural gas or on conventional liquid marine fuels. The DF in its name stands for dual fuel, and this flexibility is the engine's defining feature: it can operate in gas mode, burning natural gas as its main fuel with a small pilot injection of liquid fuel to ignite the charge, or switch to running entirely on marine diesel oil or heavy fuel oil, and it can transfer between the modes while running. In gas mode the engine works on the lean-burn Otto principle, mixing gas with a large excess of air and igniting it with the pilot fuel, which gives very low emissions of sulphur oxides, nitrogen oxides and particulates compared with a conventional oil-burning engine, helping ships meet the requirements of emission control areas and the global sulphur cap. This makes dual-fuel engines like the 46DF a leading choice for LNG carriers, which have gas available from cargo boil-off, and for cruise ships, ferries and other vessels adopting LNG as a cleaner fuel. As a medium-speed engine it runs faster than the low-speed two-stroke engines used for direct propulsion of large ships, and it is applied both as a main engine, often driving through a gearbox or as part of a diesel-electric power plant, and as a generating set. In a diesel-electric or dual-fuel-electric arrangement several such engines drive alternators feeding a common electrical system that powers propulsion motors and the ship's services, giving flexibility and redundancy. The 46DF represents the shift in marine propulsion toward cleaner-burning gas and dual-fuel machinery, and toward integrated electric power systems, as the industry works to reduce the environmental impact of ships while retaining the security of being able to fall back on liquid fuel.

MAN B&W

The MAN B&W 6G80ME-C10.5 is a large, low-speed, two-stroke crosshead marine diesel engine of the type used for the main propulsion of large ocean-going ships. It belongs to MAN Energy Solutions' ME series of electronically controlled engines, and the naming conveys a good deal about it: the 6 is the number of cylinders, the G marks it as one of the ultra-long-stroke Green series designed for high efficiency at lower speeds, the 80 is the cylinder bore in centimetres, and ME denotes electronic control of the engine. Low-speed two-stroke engines like this are the dominant form of main propulsion for large container ships, bulk carriers and tankers because they are highly efficient, can burn heavy fuel oil, and turn slowly enough (typically well under a hundred revolutions per minute) to drive a large, efficient fixed-pitch propeller directly, without any reduction gearbox. Their great stroke relative to bore, the hallmark of the G series, suits the slow propeller speeds that improve overall propulsive efficiency and fuel economy on long deep-sea voyages. The ME designation marks the shift from the older mechanically camshaft-controlled engines to electronic control. In an ME engine the timing of fuel injection and of the exhaust valve is governed by a computer system and hydraulically actuated, rather than fixed by a camshaft, which allows the engine to be optimised across its whole load range, improves fuel consumption and emissions, eases starting and manoeuvring, and provides monitoring and diagnostics. As a crosshead engine it separates the combustion space from the crankcase with a diaphragm and stuffing box, allowing the use of cylinder oil suited to heavy fuel above and clean system oil below. Engines of this size and type are the beating heart of a large merchant ship, and their reliability, efficiency and careful maintenance are central to the economics and safe operation of the vessel.

MAN B&W

The MAN B&W 7S65ME-C8.6 is a low-speed, two-stroke crosshead diesel engine built for the main propulsion of medium and large merchant ships such as tankers and bulk carriers. Like the rest of MAN Energy Solutions' celebrated ME series, its designation is descriptive: the 7 is the number of cylinders, the S marks it as a super-long-stroke engine, the 65 is the cylinder bore in centimetres, and ME signifies that the engine is electronically controlled. The super-long-stroke S design reflects the industry's drive for fuel efficiency. By combining a long piston stroke with a moderate bore, these engines run at low revolutions and develop high torque, which lets them turn a large, slow, efficient propeller directly on the shaft with no reduction gearbox. Slow propeller speeds improve propulsive efficiency, and the engines are optimised to burn heavy fuel oil economically over the long passages typical of the trades they serve, which is why two-stroke crosshead engines of this kind power the great majority of large ocean-going ships. The electronic control that defines the ME series replaces the traditional camshaft with a computer-controlled, hydraulically actuated system that governs fuel injection and exhaust valve operation. This allows injection timing and profile to be adjusted continuously for the best fuel economy and emissions across the load range, gives smoother slow-speed running for manoeuvring, and provides extensive monitoring. As a crosshead engine it has a diaphragm separating the cylinders from the crankcase, permitting separate cylinder and system lubrication suited to heavy fuel operation, and it is built to run continuously for long periods with planned maintenance of its running gear, injection equipment and turbocharging. Engines such as the 7S65ME-C are typical of the modern main engine: large, efficient, electronically managed and designed for the reliability that a deep-sea ship depends on for years of service.

MAN B&W

The MAN B&W G90ME-GI is a large low-speed, two-stroke crosshead marine engine that adds high-pressure gas injection to the electronically controlled ME platform, making it a dual-fuel main engine for the largest ships. Its designation is informative: the G marks the ultra-long-stroke Green series designed for efficiency at low propeller speeds, the 90 is the cylinder bore in centimetres, ME denotes electronic control, and GI stands for gas injection, the technology that allows the engine to run on natural gas as well as on conventional liquid fuel. Unlike the lean-burn Otto approach used by many medium-speed dual-fuel engines, the ME-GI engine injects gas at high pressure directly into the cylinder and burns it on the diesel principle, with a pilot injection of liquid fuel for ignition. This preserves the high efficiency and strong performance of the two-stroke diesel while allowing the ship to burn cleaner gas, and it largely avoids the methane slip associated with some gas engines. The engine can operate on gas or switch to liquid fuel such as heavy fuel oil or marine diesel oil, giving operators fuel flexibility and the ability to meet emission limits by running on gas in controlled areas. Engines of this size and type propel the largest merchant ships, including very large LNG-fuelled container vessels, and the GI variant is particularly suited to LNG carriers and other ships that can carry gas as fuel. As with all ME-series engines, electronic control of fuel injection and exhaust-valve timing optimises performance across the load range, improves manoeuvring and provides monitoring, while the crosshead construction allows separate cylinder and system lubrication for heavy-fuel operation. The G90ME-GI illustrates how the traditional low-speed diesel is being adapted to lower-carbon fuels, combining the efficiency and reliability of the two-stroke engine with the cleaner combustion of gas as the industry moves toward its emissions goals.

Wärtsilä

The Wärtsilä RT-flex96C is a very large, low-speed, two-stroke crosshead marine diesel engine, one of the most powerful engines ever built and long associated with the propulsion of the largest container ships. Descended from the Sulzer RTA line of low-speed engines, it has a cylinder bore of 96 centimetres and is offered with a range of cylinder numbers, so that in its largest configurations it develops enormous power to drive the biggest ships at commercial speed on a single direct-drive propeller. The flex in its name refers to the common-rail electronic control system that distinguishes it from earlier camshaft-driven engines. In an RT-flex engine, fuel is supplied from a high-pressure common rail and injected under electronic control, and the exhaust valves are likewise electronically actuated, doing away with the traditional camshaft, fuel pumps and mechanical drives. This allows the timing and rate of fuel injection to be varied freely and optimised across the whole operating range, giving better fuel economy, cleaner combustion and low, smokeless running even at very low speeds, along with flexible manoeuvring and comprehensive monitoring. As a low-speed two-stroke crosshead engine it turns slowly enough to drive a large, efficient fixed-pitch propeller directly, without a reduction gearbox, and it is designed to burn heavy fuel oil economically on long deep-sea voyages, which is why engines of this class dominate the propulsion of large merchant ships. Its crosshead construction separates the combustion space from the crankcase, allowing separate cylinder and system lubrication suited to heavy fuel. Engines like the RT-flex96C, and their successors in the WinGD X-generation, represent the pinnacle of merchant-ship propulsion engineering: immense, efficient, electronically managed machines built to run reliably for years, and their performance and fuel consumption are decisive factors in the economics of operating the world's largest cargo ships. Because a single engine of this size can represent a large share of a ship's capital cost and almost all of its fuel bill, the care with which it is operated and maintained — clean treated fuel, correct cooling and cylinder lubrication, and the timely overhaul of its running gear and injection equipment, has a direct and lasting effect on the reliability and profitability of the vessel.

Wärtsilä

The Wärtsilä X72 is a low-speed, two-stroke crosshead marine diesel engine designed for the main propulsion of merchant ships such as tankers, bulk carriers and medium-sized container vessels. It belongs to the X-generation of low-speed engines, the electronically controlled successors to the earlier Sulzer RTA and RT-flex lines, and the 72 in its name is the cylinder bore in centimetres. Offered with a range of cylinder numbers, it provides the power needed to propel ships of these types at economical service speeds. The X-series engines use electronic common-rail control of fuel injection and exhaust-valve operation in place of the traditional camshaft, which allows injection timing and rate to be optimised across the whole load range. This delivers good fuel economy, clean and smokeless combustion even at low load, flexible slow-speed running for manoeuvring, and extensive monitoring and diagnostics. Designed with a long stroke relative to the bore, the engine turns slowly and develops high torque, so it can drive a large, efficient fixed-pitch propeller directly on the shaft without a reduction gearbox, which is the arrangement that gives large ships their propulsive efficiency. As a crosshead engine it separates the combustion space from the crankcase, allowing separate lubrication of the cylinders and the running gear, which suits operation on heavy fuel oil, and versions of such engines are increasingly offered with dual-fuel capability to burn gas as the industry moves toward lower-carbon fuels. Built to run continuously for long periods, the engine is maintained on a planned schedule covering its injection equipment, running gear, turbocharging and lubrication. The Wärtsilä X72 is representative of the modern low-speed main engine (efficient, electronically managed and reliable) that sits at the centre of a merchant ship's machinery and whose performance directly shapes the fuel consumption and operating economics of the vessel. Because the main engine dominates both the capital cost and the fuel consumption of a large ship, the reliability and efficiency of an engine such as the X72, and the discipline with which it is maintained over its long working life, are decisive for the safe operation and the commercial success of the vessel.

Caterpillar

The Caterpillar 3516C is a high-speed, four-stroke marine diesel engine in a V16 configuration, part of Caterpillar's long-established 3500 family of medium-duty engines. In the marine world it is used chiefly as an auxiliary engine driving a generator to supply a ship's electrical power, and as a propulsion engine in workboats, tugs, offshore supply vessels and other craft where a compact, high-speed engine suits the installation better than a large, slow-running two-stroke. As a high-speed engine, the 3516C runs at far higher revolutions than the great two-stroke crosshead engines used for main propulsion in large merchant ships, which makes it lighter and more compact for a given power but means it is generally coupled to a generator or, for propulsion, to a reduction gearbox. Later C-series variants use electronic engine management and common-rail or unit fuel systems to improve fuel economy, control emissions and provide diagnostics, and they are offered in ratings and tunings to meet the applicable IMO nitrogen-oxide tiers and other emissions standards. Engines of this class are valued for their reliability, worldwide parts and service support, and flexibility across many vessel types. On board they typically form part of a genset package, complete with the alternator, cooling, and control systems, several of which may run in parallel to supply the ship's switchboard and share electrical load. In propulsion roles they drive the shaft through a gearbox and often a controllable-pitch propeller. Maintenance follows a planned schedule of oil and filter changes, cooling-water treatment, and periodic overhaul of components such as injectors, turbochargers and running gear. The 3516C illustrates the role of the modern high-speed marine diesel: a versatile, serviceable prime mover for power generation and for propelling the large fleet of smaller commercial and offshore vessels that support world shipping. Across its long production life the 3500 family has been continuously updated to raise efficiency and to meet successive IMO nitrogen-oxide tiers, and its very wide use means spare parts and trained service engineers are available in ports worldwide — a practical consideration that weighs heavily when operators choose auxiliary machinery expected to run for many thousands of hours.

MAN

The MAN L27/38 is a medium-speed, four-stroke marine diesel engine widely used aboard ships as an auxiliary engine driving a generator and, in some installations, for propulsion. In MAN's naming convention the L indicates an in-line cylinder arrangement and the numbers give the principal dimensions of the cylinder (a bore of 27 centimetres and a stroke of 38 centimetres) which places it among the robust, medium-bore engines that form the backbone of shipboard power generation. As a medium-speed engine it runs considerably faster than the low-speed two-stroke engines used for the main propulsion of large ships, but much slower than high-speed engines, a balance that gives it durability, the ability to burn heavier fuels, and long intervals between overhauls, while remaining reasonably compact. These qualities make it well suited to the demanding role of an auxiliary generating set, where the engine may run for long hours supplying the ship's electrical load and must start reliably and share load with other sets connected to the same switchboard. In the common auxiliary role, several such engines are each coupled to an alternator to form generating sets, and the ship's power management system starts, stops and shares load among them according to demand, providing redundancy so that the failure of one set does not black out the ship. In propulsion applications the engine drives through a gearbox, sometimes in a multi-engine or diesel-electric arrangement. Like all four-stroke marine diesels it requires planned maintenance of its fuel injection equipment, valves, turbocharger, cooling and lubrication systems, and it is designed to meet the applicable emissions standards for nitrogen oxides. The L27/38 typifies the dependable medium-speed engine on which ships rely for their electrical power and, in many vessels, for part of their propulsion, quietly underpinning the operation of everything from cargo gear to navigation equipment and accommodation services.

Wärtsilä

The Wärtsilä 20 is a compact medium-speed, four-stroke marine diesel engine widely used aboard ships as an auxiliary engine driving a generator, and in smaller vessels for propulsion. The number 20 refers to the cylinder bore of 20 centimetres, placing it at the smaller end of Wärtsilä's medium-speed range, and it is offered in various cylinder numbers to suit different power requirements. Its compactness, reliability and worldwide support have made it one of the more common auxiliary engines in the fleet. As an auxiliary engine, its main task is generating the electrical power a ship needs for cargo systems, machinery, navigation equipment, lighting and accommodation. Coupled to an alternator to form a generating set, several such engines are typically installed so that they can run in parallel and share the electrical load, with the ship's power management system starting and stopping sets as demand changes and providing redundancy against the failure of any one unit. In smaller ships and in some diesel-electric or propulsion arrangements, engines of this class also contribute to driving the vessel. Being a four-stroke medium-speed engine, the Wärtsilä 20 runs faster and is far more compact than the low-speed two-stroke main engines of large ships, while still being built for durability and long service life with planned maintenance. It can be configured to run on marine distillate fuels and, in appropriate versions, heavier fuels, and it is designed to meet the applicable IMO nitrogen-oxide emission standards. Routine care involves maintenance of the fuel injection equipment, valves, turbocharger, and cooling and lubrication systems. The Wärtsilä 20 is representative of the dependable small-to-medium marine engine that supplies the electrical power on which almost everything aboard a ship depends, and its reliability is important to the safe and continuous operation of the vessel. Its long production history and large installed base mean that spare parts, technical support and experienced service engineers are readily available around the world, which matters greatly for a machine whose continuous, dependable operation underpins the electrical supply to the entire ship and therefore the working of almost every other system aboard.

Rolls-Royce

The Rolls-Royce Azipull AZP100 is an azimuth thruster, a combined propulsion and steering unit that can rotate through a full circle to direct its thrust in any horizontal direction. Instead of the traditional arrangement of a fixed propeller shaft and a separate rudder, an azimuth thruster mounts the propeller on a steerable underwater unit, so that turning the unit both propels and steers the vessel. This gives outstanding manoeuvrability, which is why azimuth thrusters are favoured for offshore supply vessels, tugs, ferries and other craft that must position themselves precisely. The Azipull is a pulling-type thruster, meaning the propeller is mounted at the forward end of the underwater pod and pulls the unit through relatively undisturbed water, ahead of the supporting strut and gear housing. This inflow benefits efficiency and can improve the smoothness of the water reaching the propeller compared with a pushing arrangement. A bevel-gear drive transmits power from an engine or motor down through the steerable column to the propeller shaft, and the whole unit is rotated by a steering system to set the direction of thrust. Because it can vector thrust in any direction, an azimuth thruster is central to dynamic positioning, the capability by which a vessel holds a fixed position and heading automatically against wind, current and waves, essential for offshore work such as supporting rigs and installing subsea equipment. Several thrusters, controlled together by the dynamic positioning system, continuously adjust their direction and power to keep the ship on station. Azimuth units also allow a vessel to move sideways, turn on the spot and dock without tug assistance. The Azipull is representative of modern propulsion units that integrate propulsion and steering into a single steerable device, delivering the manoeuvrability and station-keeping that many specialised vessels require, in place of the conventional shaft-and-rudder arrangement of typical cargo ships.

Wärtsilä

The Wärtsilä LJX is a transverse tunnel thruster, a manoeuvring device fitted athwartships in a tunnel through the hull, usually near the bow, that produces sideways thrust to help a ship move laterally and turn. A tunnel thruster consists of a propeller mounted inside a transverse tube that opens on both sides of the hull; when the propeller turns, it draws water in one side and expels it the other, pushing that part of the ship sideways. Fitted at the bow it is commonly called a bow thruster, and some ships also have a stern thruster. The purpose of a tunnel thruster is manoeuvrability at low speed, particularly during berthing, unberthing and other close-quarters operations. By pushing the bow to port or starboard, a bow thruster lets a ship turn or move its head without relying solely on the main propeller and rudder, which are ineffective at very low speed, and it can reduce or remove the need for tug assistance in some conditions. The thrust is reversible, so the operator can push the bow either way from the bridge controls, and the unit is most effective when the ship has little or no headway. Tunnel thrusters may have fixed-pitch propellers whose thrust is varied by changing the motor speed and direction, or controllable-pitch propellers that run at constant speed with thrust set by blade angle. They are driven by electric motors or by a hydraulic or mechanical drive from the engine room. On vessels equipped for dynamic positioning, tunnel thrusters work together with azimuth or main propulsion units under automatic control to hold the ship on station. Well suited to the frequent manoeuvring of ferries, cruise ships, offshore vessels and many cargo ships, the tunnel thruster is a standard part of the manoeuvring equipment that makes a large ship far more manageable in port and confined waters.

Rolls-Royce

The Rolls-Royce Rotary Vane RV600 is a marine steering gear of the rotary-vane type, the machinery that turns a ship's rudder to steer the vessel. Every ship must be able to move its rudder reliably and with enough force to steer in all conditions, and the steering gear is the powered system that does this, responding to orders from the bridge or the autopilot. The rotary-vane design is one of the main forms of hydraulic steering gear, valued for being compact and for applying torque directly to the rudder stock. In a rotary-vane steering gear, vanes fixed to a rotor on the rudder stock sit within a housing containing matching fixed vanes, dividing the housing into chambers. Hydraulic oil, delivered by electrically driven pumps, is admitted to the chambers on one side and released from the other, so that the pressure difference rotates the rotor and with it the rudder stock, turning the rudder. Reversing the flow turns the rudder the other way. Because the torque is produced directly at the stock, the arrangement is space-saving compared with the ram-and-tiller type and delivers high turning moment, which suits it to a wide range of ships. Steering gear is safety-critical equipment, and its design and testing are governed by SOLAS. Ships must have a main steering gear capable of putting the rudder over quickly at full speed, and an auxiliary means of steering, with duplication of essential components and power units so that a single failure does not leave the ship unable to steer. Alarms, and the ability to change over to standby pumps and to control the gear from the steering compartment, are required, and the equipment is tested before departure and exercised in drills. The rotary-vane steering gear such as the RV600 exemplifies the compact, powerful and reliable machinery that turns the rudder and so keeps a ship under command.

Alfa Laval

The Alfa Laval ALCAP S-916 is a marine centrifugal separator, a machine that cleans fuel oil or lubricating oil aboard ship by spinning it at high speed so that water and solid contaminants, being denser than the oil, are thrown outward and separated from it. Centrifugal separation is vital on ships that burn heavy fuel oil, because that fuel arrives contaminated with water, sludge and catalytic fines that would damage the engine if not removed before the fuel reaches the injection system, and the same principle is used to keep lubricating oil clean in service. What distinguishes the ALCAP concept is its method of controlling separation. Traditional purifiers rely on a gravity disc, a ring of a specific size that must be selected to match the density of the oil being treated and that sets the position of the oil–water interface in the bowl. The ALCAP system dispenses with the gravity disc and instead continuously monitors the quality of the cleaned oil leaving the separator; when the sensor detects that water is beginning to break through into the clean oil, the control system triggers the separator to discharge the accumulated water and sludge. This makes the machine largely self-adjusting across a wide range of oil densities and water contents, which is a real advantage as fuels vary. In operation the separator is a self-cleaning disc-stack machine: the oil passes through a stack of closely spaced conical discs that greatly increase the effective settling area, and the bowl periodically opens to eject the separated sludge and water without stopping the process. Correct feed rate, heating of the oil to the right temperature and viscosity, and proper maintenance of the bowl, discs and seals are all essential to good separation. Machines of this kind, arranged as fuel and lubricating oil treatment units, are a core part of a ship's engine-room auxiliary systems, protecting the main and auxiliary engines from the wear and damage that dirty oil would otherwise cause.

Alfa Laval

The Alfa Laval Aalborg AQ-12 is a marine composite boiler, a type of boiler that generates the steam a ship needs while making use of the waste heat in the main engine's exhaust gases. Aalborg is a long-established name in marine boilers, and the composite design combines two heat sources in a single unit: an exhaust-gas section, through which the hot exhaust from the main engine passes to raise steam, and an oil-fired section with its own burner. This lets the boiler recover otherwise wasted energy while the ship is at sea and the main engine is running, and still produce steam independently in port or when the engine is stopped. Steam has many uses aboard a merchant ship even where it is not the means of propulsion. It heats heavy fuel oil and lubricating oil to the temperatures needed for pumping and for separation, warms cargo on some tankers, provides heat for accommodation and domestic services, and drives various auxiliary processes. Producing that steam efficiently matters for fuel economy, and a composite or exhaust-gas boiler does so by capturing heat from the engine exhaust that would otherwise be lost up the funnel, which reduces the amount of fuel that must be burned in the oil-fired section. In service the boiler must be operated and maintained with care. Water treatment is important to prevent scale and corrosion on the heating surfaces, the exhaust-gas side must be kept clean and guarded against soot fires, and the water level, pressure and safety devices such as the safety valves and level alarms must be monitored, since a boiler is a pressure vessel whose failure can be dangerous. The composite boiler such as the Aalborg AQ exemplifies the engineering emphasis on energy efficiency in ship design, integrating waste-heat recovery into the everyday supply of steam that keeps a ship's fuel systems, cargo and services working.

Sauer

The Sauer WP4060 is a marine air compressor, a machine that compresses air to high pressure for use aboard ship, most importantly to provide the starting air that turns large diesel engines over to start them. Large low-speed and many medium-speed marine engines are started not by an electric motor but by admitting high-pressure compressed air into the cylinders, so a supply of air stored in receivers at high pressure is essential, and the air compressor is the machine that charges those receivers. A compressor of this class is typically a multi-stage reciprocating machine: air is compressed in successive cylinders of decreasing size, with cooling between the stages, so that it can be raised to the high pressure (commonly around thirty bar for engine starting air) without excessive temperature. Compressing air heats it, so intercoolers between stages and an aftercooler remove heat, improve efficiency and remove moisture, while relief valves protect each stage and drains remove condensed water and oil. The compressor draws through a suction filter and delivers through a non-return valve to the air receivers. On board, starting-air compressors are usually installed in pairs or more to give redundancy, and they run automatically to keep the air receivers charged to pressure, cutting in and out as air is used for starting and manoeuvring the main and auxiliary engines and for other services such as control air and the ship's whistle. Reliability is important, because without starting air the engines cannot be started, and the compressors, receivers and associated pipework form part of the classed and surveyed machinery of the ship. Maintenance covers the valves, piston rings, cooling and the safety devices, and the correct functioning of drains and relief valves is watched closely. The Sauer WP4060 typifies the high-pressure marine air compressor that quietly performs the essential task of keeping a ship's engines ready to start.