Research Continues For More Fuel Efficiency With Lower Grade Fuels
The two major factors influencing diesel engine design and development continue to be the soaring fuel costs and deterioration in the quality of marine fuels. While most diesel designers are working to modify existing models to achieve lower specific fuel consumption, a milestone urns achieved by Caterpillar with the recent introduction of an entirely new series of highspeed, heavy-duty diesels in the S00 to 1,600-bhp range.
The past year saw several new licensing agreements between European companies and U.S. engine manufacturers. Transamerica Delaval has been licensed by the Dutch company Stork-Werkspoor Diesel of Amsterdam to manufacture and market in the lT.S. the TM 620 series, which will be known as the Enteprise1 SWD TM 620 diesel line. Waukesha Engine Division of Dresser Industries will manufacture a line of medium-speed diesels in the 1,2-10 to 4,320 blip power range under license from Sitlzer Brothers of Switzerland. And Allis-Chalmers of Milwaukee has been licensed by B&W Diesel of Copenhagen to manufacture and market the Danish company's low-speed engines in the U.S. We asked the diesel manufacturers to tell us about their latest designs and developments; the following review is based on their replies.
ALCO POWER The past year has been one of increased activity in the marine market for Alco Power Inc. With engine orders up from last year, Alco is looking optimistically toward the coming year. Early 1982 will find Alco engines being installed in vessels at three major inland yards — Dravo, Jeffboat, and St. Louis Ship. Recent installations include main propulsion engines for the towboats Jeffboat, Volunteer, Karen Ann, and Toutant, plus a tug for Gladders Towing. Current contracts include orders for a quantity of Alco engines for main propulsion of tugs and towboats.
Alco's capability in the marine market extends to specialized applications as well. One such application is the dredge Eagle 1, built by Avondale for Eagle Dredging, which entered service earlier this year. A split-hull hopper dredge, the Eagle 1 has two Alco 16-cylinder 251s for main propulsion and two Alco 6-cylinder 251s to drive the dredging pumps. Forced to meet stringent requirements, these engines are able to operate at a side pitch of 23 degrees, which becomes necessary when the vessel's split hull is opened to dump the dredging spoils. In its ongoing effort to respond to the demands of the market, Alco will continue its research and development program for engines operating on blended fuel.
In addition, Alco offers a marine training school at its St. Louis location to familiarize operators with engine characteristics and maintenance procedures. The "hands-on" experience offered by this program has been well received by those who have attended.
Historically, Alco has provided diesel engines for a variety of applications. All markets will benefit from the introduction of the Alco 270, a new engine now in production at the company's Auburn, N.Y., plant. Available in 6-, 8-, 12-, 16-, and 18-cylinder configurations, the larger-bore 270 offers more power (1,400 to 5,800 bhp) in a smaller package to complement the existing 251 model.
Many of the 251's favorable characteristics have been incorporated into the 270.
Developed as an outgrowth of the Ruston RKC series diesel, the 270 is an engine of proven design and capability. Of interest to vessel owners is the 270's ability to burn heavy fuels up to 1500 seconds Redwood No. 1, and low fuel consumption under all operating conditions. The first 270s are expected in service in the spring of 1982, to be installed in a 9,000- bhp towboat.
For additional information on Alco Power's engines, B&W— ALLIS-CHALMERS Highest fuel efficiency, largest worldwide orderbook, license agreement with a U.S. manufacturer, M.A.N.-B&W Diesel market leader in large diesels: These are some of the ways in which the Danish diesel designer has made news during the past year. E a r l i e r this year a license agreement was signed with Allis- Chalmers of Milwaukee for the manufacture and sale/marketing of B&W low-speed engines on the U.S. market.
The old Burmeister & Wain diesel traditions are carried on in the new company, B&W Diesel, which after the takeover by M.A.N, is enjoying a well-secured financial base. In order to intensify the cooperation, a joint company has been formed — M.A.N.- B&W Diesel GmbH — to coordinate all diesel engine marketing and licensing activities.
Development of 2-stroke, lowspeed engines will be concentrated in Copenhagen as B&W's responsibility. These engines will follow the uniflow scavenged design that in recent years has made commendable improvements in fuel consumption.
B&W recently announced, and already contracted for, an up- rated version of the L-GFCA engine. The new L-GB engine has 15 percent higher output with a 3 gram per horsepower-hour reduction in fuel consumption. A fuel-optimized version, the LGBE, has the same rating as the successful L-GFCA engine but with a substantial fuel reduction of 6 grams per bhp-hour. The L-GB and L-GBE, which will be available from 1983 onward, will be equipped with automatic adjustment of the fuel injection lead to achieve a further reduction in fuel consumption at part load.
The new L-GB and L-GBE Series will include a completely new size of B&W crosshead engine — 350 mm bore, developing 680 bhp per cylinder at 200 rpm. With outputs down to 2,720 bhp, it will be a direct competitor to many four-stroke, trunk piston engines.
The joint M.A.N.-B&W fourstroke, trunk engine program embraces the original M.A.N, designs and the smaller B&W T/V 23L and S U 28L models, capable of burning heavy fuel.
Recently, the largest oceangoing tugboat ever built in the U.S. for Belcher Oil Company, was delivered equipped with a B&W low-speed engine of the type 7L67GFCA.
Another recent milestone was the installation of long-stroke, low-speed B&W engines in RO RO vessels for the Swedish shipowner Brostrom, utilizing the engines' ability to accommodate an extremely low engine room height.
For additional information on the B&W Diesel engine program, B&W ALPHA B&W Alpha division of B&W Diesel A S is a companv in the MAN-B&W Diesel group'that designs, manufactures, markets, and services complete ship propulsion systems consisting of diesel engines in the power range of 475 to 4,770 bhp. Alpha Diesel has been producing these propulsion packages, which include controllable- pitch p r o p e l l e r s , since 1903. Current production is about 180,000 bhp annually, equal to 1,000 cylinders for ship propulsion, mainlv to tvpes T V23L-VO and S U28L-VO.
The T23L-KVO in-line engine and the V-built Y23L-YO have a bore of 225 mm, stroke of 300 mm, and output of 155 bhp per cylinder at 825 rpm. The S28L-YO in-line and U28L-YO Vee engine have a bore of 280 mm, stroke of 320 mm, and output of 265 bhp per cylinder at 775 rpm.
These engines were designed and developed to meet the demand for using lower grade fuels. The initial experience with intermediate fuel was based on B&W service results with the twostroke, direct-coupled diesel engines for ship propulsion and auxiliary f o u r - s t r o k e engines, of which the first were in service before 1960. Extensive tests have been carried out with different lube oils and fuels of up to 3500 Sec. Redwood.
Since 1974 Alpha Diesel has tested different components to suit the demand for heavy fuel operation. For the past five years it has also followed up on service experience with its parent company B&W Diesel to find the best solution to obtain the highest benefit by using poorer quality fuel.
Today there are about 600 Alpha Diesel 4-stroke engines in service for main propulsion. Of these, some 135 are running on fuel of 250 to 1500 Sec. Redwood with good results.
More than 90 percent of the Alpha propulsion systems have been delivered with controllablepitch propellers of the company's own design — a rugged construction that features a heavy mechanical linkage that has proved extremely reliable over the past 75 years.
For additional information on B&W Alpha propulsion systems, CATERPILLAR The introduction of an entirely new series of diesel engines is a rare occurrence in the marine industry. Caterpillar accomplished this feat with the introduction of its entirely new 3500 Series earlier this year. This new family of high-speed, heavy-duty diesel engines in the 800 to 1,600 bhp (600-1,200 kw) range is designed to provide optimum value for a wide variety of applications. The 3500 family will ultimately consist of V8, V12, and V16 models. The V12 (3512) was the first model produced, for limited distribution in the United States and Canada, with continuous and intermittent ratings of 1,055 bhp and 1,200 bhp, r e s p e c t i v e l y. Worldwide 3512 availability was anticipated during the third quarter of this year. Limited geographical distribution of the V8 (3508) is planned for the fourth quarter 1981; the V16 (3516) is similarly planned for 1982.
The 3500 Series is an additive to the company's 300 Series engine. The latter will remain in the Caterpillar product line to serve customers and the company's own product needs.
The 3500 Series engines were designed to produce 100 intermittent horsepower (74.6 kw) per cylinder, industrial configuration. Displacement is 2,105 cubic inches for the 3508, 3,158 cubic inches for the 3512, and 4,211 cubic inches for the 3516. All three models are four-cycle, dual-turbocharged, and jacket water aftercooled. The 3500 Series will be available in marine propulsion and large marine auxiliary configurations. Typical 3512 applications include workboats, fishboats, dredges, cranes, and standby and prime power installations. The 3512 marine propulsion and marine auxiliary configuration has a 60- degree Vee to reduce physical engine dimensions for ease of installation. Inlet manifolds, aftercooler, and exhaust manifolds are mounted in the Vee for compact, uncluttered design.
Engines must perform with a minimum of downtime to keep operations profitable. The 3500 Series offers conservative loads, stresses, and speeds in a largedisplacement, low-bmep package.
From metallurgy through machining, assembly, and testing, all component specifications and tolerances are accurately maintained to assure customer value.
The 3500 Series has a large displacement of 263 cubic inches per cylinder. Turbocharging and aftercooling further increase engine performance and efficiency while decreasing thermal load. The cam-actuated, unit injection fuel system provides outstanding performance and economy. Threering piston design simultaneously reduces internal engine friction while maintaining oil control and compression.
Another benefit of the 3500 Series is that commonality of parts reduces inventory requirements, i n c r e a s e s parts interchangeability, and reduces service time due to maintenance personnel familiarity. All 3500 Series cylinder heads, connecting rods, valves, pistons, and numerous other components are interchangeable.
Specialized attachments specifically designed for the 3500 Series include g e n e r a t o r sets, matching marine transmissions, optional bases and foundation hardware, cooling systems, and various air cleaner arrangements. The 3500 Series represents a fine balance of advanced engine design and application flexibility. High-speed capability allows the engines to compete effectively in applications horsepower and speeds not previously available with existing Caterpillar diesel engines. Finally, the 3500 Series engines are mechanically simple and efficient, and use proven components components that have a high degree of commonality.
With the introduction of the 3500 Series engines, Caterpillar now has one of the most complete, technologically advanced engine product lines in the world — a product line that is celebrating its 50th anniversary in 1981.
For additional information on the 3500 Series and other Caterpillar engines, COLT/PIELSTICK Pielstick PC Series heavy-duty, four-cycle engines are among the most widely used marine diesels in world shipping service. A total of almost 3,000 have been built by all licensees; of this total, almost 2,400 engines have been for marine service.
Fairbanks Morse Engine Division, Colt Industries, has been the U.S. licensee for the PC-2 Series since 1970 and during that time has sold 124 of these engines, of which 56 were for marine service. In addition, the PC-4 Series is now being offered for marine applications.
PC2.5 engines have a rated speed of 520 rpm and are available in 12-, 14-, 16-, and 18-cylinder configurations. Maximum continuous output is 7,800, 9,100,10,400, and 11,700 bhp, respectively. Bore is 400 mm, stroke is 460 mm, and displacement per cylinder is 3,528.3 cubic inches. Compression ratio is 11.5:1, and bmep is 280.6 psig.
The engine frame is a welded fabrication, providing maximum structural capability with minimum weight. Individual cylinders are replaceable. Individual water jackets prevent any contact and corrosion between the jacket cooling water and the f a b r i c a t ed crankcase. Caged exhaust valves can be removed and serviced without disturbing the cylinder head. The PC2.5 engines have low fuel consumption over a wide output range, and the ability to burn heavy fuel having high vanadium content. More than 50 percent of the engines in operation run on residual fuels.
Early in 1973, SEMT (Societe d ' E t u d e s de Machines Thermiques) presented to its licensees its latest development — a new four-cycle, heavy-duty engine — the PC-4. This engine was conceived with the dominant thought of 100,000-bhp marine power plants with the economy and practical features of the mediumspeed engine. To accomplish this goal, design engineers had to focus on a substantial increase in power per cylinder, low specific weight per horsepower, minimum operating costs, and extended time between overhauls.
Thus, the PC-4 was born. The bore and stroke were increased to 570 mm and 620 mm, which extended the horsepower range to 1,500 horsepower per cylinder. The configuration of the engine is a Vee design with 10, 12, 14, 16, or 18 cylinders. Whereas the PC-2 has an operating speed of 520 rpm, the PC-4 operates at 400 rpm.
In general, the structure of the PC-4 engine is similar in appearance to the PC-2 Series. It has a monobloc frame made of cast steel components and steel plates welded together. It has an underslung crankshaft, with each bearing cap being fixed through two vertical tie-bolts. Individual cylinders, including water jacket, liner, and head are tightened on the frame through eight long studs. The inlet manifolds are located outside the engine, and the exhaust manifold inside the Vee. Lateral camshafts are located in the frame.
With the PC-4 it is feasible to supply up to 54,000 bhp with two engines, which approximates the maximum power that can be absorbed by one propeller. A 100,000-bhp marine propulsion system is possible with four engines on two propeller shafts.
Four engines can be set side by side in a ship's hull through a new design configuration. This design also allows far-aft placement of propelling machinery and permits maximum use of space for cargo. PC-4s are available as reversible engines, with full power output in reverse, and can be equipped for automatic operation. During the past year, Colt- Pielstick activity has been highlighted by the U.S. Navy LSD-41 application and the three Catugs built by Avondale for subsidiaries of Occidental Petroleum.
For additional information on Colt-Pielstick marine diesel engines, CUMMINS Cummins "K" series marine diesel engines are proving their mettle in a variety of workboat and fishboat applications. According to Cummins, its K engines respond to the market's demand for increased horsepower, better fuel economy, and easier maintenance. At the top of the K line is the KTA-3076, a turbocharged and aftercooled 16-cylinder diesel that produces 1,250 bhp at 1,800 rpm during continuous-duty operation. The V-16, 3,067-cubic-inch engine weighs just 10,700 pounds, providing a high horsepower-toweight ratio. Its fuel consumption is rated at 63 gallons per hour. Individual cylinder heads and replaceable wet-type liners help ease service.
The 300-ton towboat Paul A.
Wronowski, recently put into service by John A. Wronowski's Thames Shipyard in New London, Conn., is the first vessel powered by the KTA-3076; the 90-foot boat is powered by two of them. Mr. Wronowski points to long years of satisfaction with Cummins engines and service, and says another big reason he chose Cummins is his concern for fuel economy.
The newest towboat to enter the fleet of Brent Towing Company of Greenville, Miss., the Melinda Brent, is powered by twin Cummins KTA-2300 engines. The KTA-2300 produces 940 bhp at 1,800 rpm during continuous duty. The V-12, 2,300-cubic-inch engine is also available in a non-after- cooled model, the KT-2300, rated 700 bhp at 1,800 rpm. Both 2300s feature the same easy maintenance characteristics as the KTA- 3067.
Brent Towing is among the first inland waterway operators to take advantage of the K's fuel economy and performance, although the engine has been a favorite of crabber and trawler operators since its introduction in 1979. The 2300 is said to be one of the most f u e l - e f f i c i e n t diesels available for its size, with a fuel consumption rating of 47.4 gallons per hour in continuous-duty applications.
The smallest entrant in the Cummins K series is the KTA- 1150, a turbocharged and aftercooled, 1,150-cubic-inch, in-line six rated 520 bhp at 1,800 rpm for continuous-duty operation. It has the most economical fuel consumption in its horsepower class, according to published manufacturers' fuel consumption curves.
Shippen Marine Inc. of Houston recently put into service the first workboat to be powered by four KTA-1150 engines, the Comet, a 110-foot crew/supply boat.
The KTA-1150 and its nona f t e r c o o l e d version have also proven popular among fishing fleets, including Singleton Fleets, Inc., a 70-boat shrimping company based in Key West, Fla. Its most recent 15 boats are powered by 1150s. Company president Henry Singleton says he selected Cummins engines because of superior fuel economy and attentive field service.
Cummins Engine Company started manufacturing marine diesel engines in 1921 and has since become a leader in marine diesel technology. In 1932 Cummins introduced the first highspeed marine diesel, and followed up in 1937 with the first supercharged marine diesel. In 1952 the company significantly boosted the horsepower of its marine engines by introducing the first high-speed turbocharged diesel. Cummins engineers tackled the size and dimension problems posed by early marine diesels when they introduced the first "oversquare cylinder" marine diesel in 1961.
Today Cummins offers seven different series of marine diesels for a full range of workboat, fishboat, and pleasure craft applications. For additional information on Cummins marine diesels, DETROIT DIESEL The trend has been for more and more horsepower, and the Detroit Diesel Allison division of G.M. has responded with higher ratings for its high-output 149 series. The Detroit Diesel 16V- 149TI, turbocharged and intercooled diesel engine delivers up to 1,570 bhp in marine applications, 1,800 bhp in other indus- and production whose keynote is versatility. It is intended for the widest possible range of ship propulsion duties—direct coupled in vessels where higher propeller speeds are used, or geared to give optimum propulsion efficiency at generally lower cost.
The CC 600, being a 2-stroke, crosshead type engine, will run on the cheapest low-grade fuel oil; the design throughout has taken into account the fact that the quality of such fuel will continue to deteriorate.
Despite the presence of a crosshead, separated crankcase, and the working spaces typical of a more t r a d i t i o n a l low-speed 2- stroke engine, the low stroke/bore ratio adopted in the CC 600 leads to an extremely compact design. Producing 1,650 hp per cylinder at 250 rpm in versions from 4 to 10 cylinders, this engine can be fitted into almost any machinery space, however restricted, as its compactness is complemented by a unique facility to withdraw the piston without its rod in a much reduced overhauling height.
The CC 600 engine retains all the characteristic design features of the previous GMT low-speed, 2-stroke engine range — the B 1060, C 900, C 780, and C 600 types — and its construction details are solidly based on the wealth of experience built up over the many years during which the validity of the design principles has been proved in the previous low-speed engine types. It differs from the other engines in that it has a low bore /stroke ratio of 1.33:1 as opposed to the normal ratio of about 2:1.
Much interest in the CC 600 is already being shown by clients in both the marine and industrial sectors, and many promising projects are being studied.
The first CC 600 was installed recently on the "Marigola," a sophisticated 12,000-dwt petrochemical tanker constructed at Italy's M. & B. Benetti yard. It is a fivecylinder unit of 8,250 bhp.
A market of particular interest could well develop for the CC 600 design from the increasing number of cases where conversion from existing steam plants is being considered. With a pre-established propeller speed and engine room configuration, these installations usually demand a geared plant. Their large (albeit diminished) power requirements and high utilization factor underline the importance of burning the most economical fuel available to achieve the objective of the conversion. The CC 600 fits these requirements admirably.
GMT's B 600 engine is a slowspeed 2-stroke of 1,500 bhp per cylinder at 160 rpm, and was designed essentially as a compact, simple, and reliable engine that can be built at a competitive cost and is particularly easy and economic to maintain. This engine is planned to meet the needs of the substantial and growing market for smaller ships of all kinds where direct-drive, low-speed engines can be accommodated. It is adaptable to give optimum efficiency over a range of maximum service speeds from 145 to 160 rpm.
For further information, KRUPP MAK H a v i n g made a start with 8,000-bhp engines for ferries, Krupp MaK subsequently began supplying other important sectors of the North American market. MaK engines are now in service as main propulsion plants on the Great Lakes, in the Atlantic and Pacific fishing industry, in dredging, in tug/barge systems, and also as auxiliary marine engines. In addition to numerous marine diesel oil engines, more than 20 engines for operation on heavy oil have been sold to North American shipping companies. This reflects the great interest shown by American customers in heavy-oil diesel engines.
G. Kuhl, president of Krupp MaK Diesel Inc., points out that his company has always stood by its product and given its customers efficient after-sales service. In Chicago, close to the world's busiest airport, Krupp MaK set up its sales and service center, including a comprehensive spares depot. Advisory and after-sales service for customers is in the hands of MaK's own specialists, who have many years' experience with MaK engines.
Krupp MaK supplies heavy-oil engines in the output range from 740 kw (990 bhp) to 9,000 kw (12,070 bhp). The M 331/332' 282 engines, with configurations of 6, 8, or 12 cylinders, has a bore of 240 mm and output range from 740 kw to 2,200 kw. The M 452 / 453 model, with 320-mm bore and power output from 880 kw to 4,800 kw, is manufactured with 6, 8, 9, 12, or 16 cylinders. With the same cylinder configuration, the M 551 552 has a bore of 450 mm and output from 3,200 kw to 9,000 kw. The biggest engine in the line, the 580-mm bore M 601, is provided in 6, 8, or 9 cylinder versions with output ranging from 6,000 to 9,000 kw.
MaK diesels work on the 4- stroke principle and are manufactured as in-line and V-type engines. All MaK engines are distinguished by their robustness and low specific load characteristics. The mean pressures of all the engines lie below 18 bar. Except for those with a 240-mm bore, they have multi-section engine blocks with tension-rod assembly and embedded crankshafts.
The structural components enclosing the combustion chamber are specially designed for heavy-oil operation. Outstanding features include high resistance to wear and to high- and low-temperature corrosion, and l ow component temperatures through intensive cooling.
Other features include built-up pistons with steel crowns and hardened annular grooves; specially designed piston rings with chromium-plated working surfaces ; bath-nitrided liners with high resistance to wear and corrosion, with wear values below 0.01 mm per 1,000 hours; and intensively cooled exhaust with wear-resistant armoring, manufactured by MaK to the highest possible standards and tested down to the last detail.
MaK engines have proved reliable in all applications. Krupp MaK is devoting particular at- tention to the following objectives in the field of research and development: Further reduction of specific fuel consumption combined with reliable combustion of the lowest grade bunker fuels; Participating in working groups with the aim of obtaining residual heavy oils suitable for marine purpose; Improvements in bunker fuel operation by retaining the usual load characteristics and by intensive research into materials.
For additional information on Krupp MaK engines, M.A.N.
The current oil market situation requires engine builders to concentrate their efforts on designs with both low fuel consumption and the capability of running on heavy fuel oil. Engines with a low fuel consumption and high heavy fuel oil compatibility demand a high firing pressure mean effective pressure ratio.
The engines included in the current M.A.N.—B&W production program have been designed with a view toward a high firing pressure ratio. In continuous service, the engines with bores from 32 cm to 52 cm operate at firing pressures of up to 145 bar. By means of precision changes not involving extensive redesign, high firing pressures can be attained with mechanical stresses remaining within controllable limits.
The engine program of M.A.N. (Maschinenf a b r i k Augsburg- Nurnberg AG) includes five fourstroke engines with bores from 200 to 520 mm, and five twostroke engines with bores from 520 to 900 mm — three of which are long-stroke versions. The four-stroke engines cover an output range from 134 to 1,187 bhp per cylinder, and the two-stroke engines from 1,187 to 3,889 bhp per cylinder. The mean effective pressure of the four-stroke engines is 20 bar (25 bar with twostage supercharging), and that of the two-stroke engines is 13 bar and 14.5 bar for the lowspeed types and approximately 15 bar with the two-stage H engines. The maximum cylinder pressure of the medium-speed engines is up to 145 bar, and that of the two-stroke engines is 115 bar.
Today's engine production program at M.A.N, thus combines, on a high-power level, proven principles with present and future demands. The most important de- velopment targets for the updated program were: Ability to burn heavy fuel oils up to 3,500 seconds Redwood 1 in the case of four-stroke engines, and up to 6,000 sRl in the case of two-stroke engines; adherence to proven design concepts wherever expedient ; variation in turbocharger arrangement and selection of optimum speed; type of construction fully developed in terms of production, engineering, and maintenance; and high quality standard.
By proven design principles M.A.N, understands that for as many components of different engine types as possible, the same design solutions are used, permitting the transfer of computed and measured results from trial data and practical experience. The constant demand from the shipowners and shipyards for a smaller engine developing below 1,000 kW (1,341 bhp) and the rising interest in smaller stationary units for combined power/ heat generation prompted M.A.N, to develop the 20 27 engine. This engine is available as an in-line unit with four to nine cylinders, and as a V engine with 12 to 18 cylinders.
The 20 '27 engine is intended mainly for the following applications: as a propulsion engine for smaller vessels; as an auxiliary engine for power generation aboard ships; for stationary power- generating p l a n t s ; and for plants combining power generation with waste heat recovery.
The 20 27 engine is offered in diesel, spark-ignited gas, and dualfuel versions. The cylinder rating of the diesel engine is 100 kW (134 bhp) at 1,000 rpm according to the ISO definition. Its mean effective pressure and mean piston speed are 14.15 bar and 9 meters per second, respectively.
For additional information, MOTOREN- UND TURBINEN-UNION The latest addition to the diesel line of West German engine manufacturer Motoren- und Turbinen- Union is a new 16-cylinder engine in the 396 Series, extending the power range of the Series to 2,400 bhp. MTU's 02 version of the 396 Series has found wide acceptance throughout the world, with some 1,600 engines in V 6, V 8, and V 12 models in service up to mid-1980.
Now, based on long operating experience with the 02 version, MTU has introduced the 03 version of the 396 Series, providing a further increase in performance. Major technical modifications c o n t r i b u t i n g to the increased performance are an increased mean effective pressure with a concurrent reduction of the pressure ratio, and introduction of composite pistons, as well as better matched turbocharger and injection systems.
MTU cites intensive turbocharger research, in particular, that allowed a considerable rise in the engine output without increasing specific fuel consumption.
Another important feature is the introduction of the cylinder cutout, which minimizes any problems during startup, idling, and part-load service.
The actual cutout is effected with a divided injection control system developed by MTU. To cut off fuel to selected cylinders, an expansion piston is filled with oil and holds one section of the control rack at zero delivery while the other section operates normally. The long-stroke (185 mm) 16V 396 TC engine has a per cylinder output of 111 hp at 1,650 rpm for commercial vessels, 143 hp at 1,900 rpm for fast vessels, and 150 hp at 2,100 rpm for highperformance craft.
The 396-03 engine series possesses an unusually high degree of power concentration and maximum accessory integration. Its main features include extremely compact construction, favorable power-to-weight ratios, favorable bulk-to-power ratios, and direct flange mounting of driven equipment and driveline components.
The various drive units are arrived at by combining identical prime movers with applicationoriented, thoroughly proven accessories. These packages are tested in their ready-to-install condition in the factory test cells under realistic on-site conditions. They can be placed in operation almost immediately on site after the support and power transmission systems have been connected. Special features of these power packs include functional reliability, easy access to the engine and accessory components, and ease of maintenance, the latter including simple maintenance procedures, low maintenance costs, and simplified spare parts inventories. MTU's total diesel engine program ranges from 435 to 7,080 bhp, with a choice of rpm from 1,000 to 2,400. Building on the experience gained with the 956 counterpart, MTU developed the 1163 family, which is aimed especially at 60 Hz power generation and marine applications. Owing to the extended length of the stroke, the power offered by the 1163 model at 1,200 rpm is the same as that of the 956 engine at 1,500 rpm, with the per-cylinder as high as 354 hp.
For additional information on MTU engines, N I I G A T A ENGINEERING Niigata Engineering Company, Ltd. of Tokyo started manufacturing diesel engines for marine use in 1919, and currently produces a wide variety of diesels ranging in power output from 90 to 27,000 bhp. With its cumulative production reaching 15 million bhp, Niigata has grown into a manufacturer of medium- and small-size diesels.
Drawing on its long experience and know-how, the company recently completed an energy-saving system for marine use to cope with the rising price of fuel oil. This main engine-driven electric power generating system using the Omega clutch is said to consume much less fuel than any previous main shaft-driven system. It has made a steady supply of power possible without being affected by the rpm of the main engine.
Notable features of the system include: Adoption of the Omega clutch stabilizes the speed of shaft revolutions at the output even if the revolution speed at the input should change drastically. As a result, main engine-driven electric power generation becomes possible even for vessels with fixedpitch propellers, which normally makes such power generation difficult. As it enables the main engine to drive the generator, grade C heavy oil can be used in place of the normally used grade A heavy oil. The price difference between the two grades of heavy oil results in a saving of 25 to 30 percent in power generation cost.
Smooth switch-over — without blackout as originally feared — from the main shaft-driven generator to the independent auxiliary generator in a crash astern while at sea or when navigating at slow speed in entering or leaving port, has been verified.
For additional information on Niigata diesels and the power generating system, OOSTERHUIS/ MITSUBISHI During the late seventies, Oosterhuis Industries researched the U.S. domestic and foreign engine market f o r lower horsepower, high-rpm diesels capable of operating successfully on lowerquality fuel oils. This search resulted in the appointment of Oosterhuis as distributors of SN and Daiya diesels for Mitsubishi Heavy Industries America, Inc. The high-speed Mitsubishi SN Series diesel engines are manufactured by Mitsubishi at its modern plant in Sagamihara near Tokyo, and shipped to Oosterhuis in standard execution. At Oosterhuis' facilities, engines are further packaged for U.S. domestic use, which includes the installation of U.S.-made SN fullflow lube oil filters, and the incorporation of S y n c h r o - S t a rt overspeed devices and Murphy instrument panels.
The Mitsubishi SN Series are available in a power range of 350 to 1,600-bhp as propulsion units for offshore supply vessels, tugboats, pushboats, and for generator drives and other applications. The rpm ranges from 1,200 to 1,800 at maximum continuous rating.
Recent orders include quadruple engine installations for tug/supply vessels utilizing two S16N and two S8N engines driving through h y d r a u l i c compound gears, with master and slave controls and fixed propeller. The 8- cylinder S8N starboard engine drives, while disconnected from the propeller shaft, a mud compressor by means of a front frontmounted power take-off. The portside S8N engine has a similar hook-up with a fire pump connected to a high-pressure, largecapacity fire monitor on deck.
Other quadruple installations call for use of four S16N engines with controllable-pitch propellers. In addition to the packaging and marketing of Mitsubishi SN diesels, O o s t e r h u i s Industries, through its affiliated company, A m e r i c a n Brons Corporation, maintains a license for manufacturing of Turbodiesels designed by Brons Industrie of the Netherlands. The first American Brons diesels became operational during 1979. They have logged approximately 10,000 hours, and have proven to be reliable and economical to operate.
For additional information on the Mitsubishi SN Series and the American Brons Turbodiesels, PAXMAN DIESELS U.K. engine builder Paxman Diesels has developed a new supercharged engine in a bid for submarine orders. Derived from Paxman's Valenta engine line, the now model relies on a mechanical supercharger rather than a turbocharger. The company hopes that this engine will operate satisfactorily when a submarine is running with only the snorkel above the surface, when there can be a severe restriction on incoming air and outgoing exhaust gases.
Paxman took full advantage of existing centrifugal compressor technology by using the supercharger rotor and involute from the Napier NA250 turbocharger. The result, according to the company, is an engine with an output similar to the turbocharged engine less the power required to drive the supercharger, but with much greater tolerance of changing inlet depression and exhaust back pressures.
To maintain commonality with the standard Valenta engine, the supercharger drive has been added to the free end of the engine. The drive increases the crank-- shaft's 1,350 rpm to 24,000 in two stages. Primary speed increase is by epicyclic gears that drive into a fluid coupling before the secondary spur gear stage. The first engine is undergoing comprehensive testing and has been run at outputs up to 1,518 kW at 1,350 rpm. A second unit is undergoing acceptance tests under submarine conditions at a Ministry of Defence facility. For further information on Paxman diesel engines, ROLLS-ROYCE Early next year Rolls-Royce plans to introduce a new 12-cylinder diesel engine, the CV 12, for installation in fast patrol craft and rescue vessels. This engine, in a 60-degree Vee configuration, can deliver 750 bhp at 2,100 rpm, enough power to drive a 50-foot boat at speeds up to 28 knots. Derived from the Rolls- Royce Condor 12V1200 already used in tanks and generating sets, the reliability of the CV 12 has been proven.
The CV 12 has been designed to meet the needs of police and customs all over the world. The engine is also aimed at the search and rescue services.
With a net dry weight of about 4,000 pounds, the CV 12 will have a very favorable power/weight ratio. It will have twin turbocharged, rear-mounted and twin high-mounted camshafts, geardriven from rear gear trains.
The CV 12 cannot run on heavy fuel and must burn gas oil. But for specialized operations where high speed is essential and time is costly, the new Rolls-Royce engine should find a market.
For further i n f o r m a t i o n on Rolls-Royce diesels, SEMT-PIELSTICK The first cargoships powered by SEMT-Pielstick diesel engines entered service more than 25 years ago and became the forerunners of a fleet that at present aggregates more than 1,000 vessels propelled by the modern PC2-5, PC3, and PC4 versions of the now famous Pielstick design. During the past year SEMTPielstick, along with other marine diesel designers, had to face the second fuel crisis, which had two main consequences: the cost of a ton of fuel increased above $200, and the oil refineries developed new processes and will supply lower quality fuels for marine uses.
To cope with these problems, SEMT-Pielstick concentrated research and development on a decrease in fuel consumption and use of the worst quality fuel. It has developed new engine models with higher cylinder output and, particularly, lower specific fuel consumption. These engines, with the same bore and stroke as their predecessors, have been designed with all the experience already gained with them.
The PC2-6, with bore of 400 mm and stroke of 460 mm, has a maximum continuous rating of 750 bhp per cylinder at 520 rpm, and specific fuel consumption of 136 grams per horsepower-hour at 85 percent of mcr. The PC4-2 has a bore of 570 mm, stroke of 620 mm, and mcr of 1,650 horsepower per cylinder at 400 rpm.
This engine has specific fuel consumption of 134 grams per horsepower- hour at 85 percent of mcr.
These two engines are also offered in an economical, derated version. The PC2-6-E has an mcr of 675 horsepower per cylinder at 520 rpm, and specific fuel consumption of 134 grams per horsepower- hour at 85 percent of mcr.
The PC4-2-E, with mcr of 1,500 horsepower per cylinder at 400 rpm, has specific fuel consumption of 132 grams per horsepowerhour at 85 percent of mcr. The new engine specifications permit the burning of fuels with gravity lower than 0.99, viscosity of 600 est at 50 C, and sulphur content of 5 percent.
Another solution is the design of an economical engine room, which can easily be adapted to the particular needs of almost any type ship, thanks to two basic advantages of medium-speed engines: the necessary use of a reduction gear allows the selection of the most economical propeller speed, resulting in a decrease of the propulsion power by about 3 percent for each 10 rpm propeller speed decrease; the heat that can be recovered from a medium-speed engine is some 60 to 70 percent higher than that from a low-speed engine of the same power.
As a consequence, it is possible to supply the full electrical demand at sea on bulk carriers and general cargo ships at service power as low as 8,000 horsepower. Some 15 ships are already equipped with turbogenerators running on steam produced by the exhaust gas energy, without any diesel generator sets operating while at sea.
Super-economical engine room designs make full use of waste heat recovery possibilities. The waste heat can be used for ship's service purposes or for heating condensate water. It can use the calories eliminated in the first stage of the air cooler to create a second stage of steam pressure. The power of the turbogenerator exceeding the ship's electrical demand can be fed to the propeller, either by mechanical coupling of the steam turbine of the turbogenerator to the gear box through a power take-off, or by the use of a static frequency converter supplying its regulated current to a shaft generator used as a motor.
Such super-economical installations, the first versions of which are already in operation and the second versions under construction, provide a total specific fuel consumption as low as 120 grams per horsepower-hour, operate any given ship with the lowest possible propulsion power, eliminate diesel generator operation at sea, and burn the poorest quality fuel. For additional information on SEMT-Pielstick engines, STORK-WERKSPOOR Recent sales developments announced by Dutch engine builder Stork-Werkspoor Diesel b.v. of Amsterdam include three 6-cylinder TM 410 diesels and one 9-cylinder TM 410 ordered by Dutch shipbuilder de Merwede for the dredging company Zanen Verstoep of The Hague. These engines will propel a new cutter dredge, and also drive its sand pumps. Zanen previously used TM 410s to power its cutter dredges Libra and Aquarius. Two 9-cylinder 410s were ordered by IHC-Smit as the main engines for a new hopper dredge due for delivery to Zanen Verstoep next January. Harlingen, the Dutch shipbuilder, has ordered a 6-cylinder TM 410 engine, with an output of 4,000 bhp at 750 rpm, for Dutch shipowner Kennemerland. This engine will power the biggest deepsea trawler ever built in the Netherlands. The vessel is scheduled for delivery in March 1982.
Stork's latest engine model, the TM 620, has entered service in a number of main propulsion applications. A single V-form, medium- speed TM 620 of only 12 cylinders has an output of 22,000 bhp (16,200 kw).
With fuel consumption such an important factor today, SWD continues to concentrate its research and development efforts in this area. Developments are made constantly on many engine details to reach the best values possible. When first introduced, the TM 620 engine had a fuel rate of 190 grams per kw-hour.
From the beginning, the TM 410 and TM 620 engines were designed and developed to run on heavy fuel. As a consequence, only small adaptations are necessary for the fuels of increasingly inferior quality that are expected to appear on the market in the near future.
For additional information on Stork-Werkspoor engines, SULZER The modern Sulzer RL crosshead diesel engine range, containing the RL 56, RL 66, RL 76, and RL 90, is now complete. This completes the development of a loopscavenged, low-speed engine series under very largely changed conditions, where the priorities have been dominated by fuel economy and fuel quality aspects.
In the past, the development of two-stroke diesel engines has had two major priority aspects: increase in power and improvement of reliability. During the design evolution of the past 20 years, the output of the Sulzer low-speed engine was increased by 74 percent and, despite a large increase in firing pressures of approximately 55 percent, the reliability was improved substantially as a result of unprecedented development efforts.
The oil crisis in 1973 had a tremendous impact on the philosophy of engine design and development. The relative weight of fuel and lube oil cost out of the total cost has taken such a large share that it is only logical that economical aspects are now predominant criteria for the engine designer.
Major features of the RL type engine include: new type of turbocharger with increased efficiency and pressure ratio range; foundation bolts arranged in one row on the outside; bedplate with i n t e g r a t e d thrustblock; single columns; one-piece gear column; simplified scavenge air receiver; one-piece, b o r e - c o o l ed cylinder cover with eight bolts; bore-cooled (water) piston crown; bore-cooled cylinder liner; enlarged crosshead pin with improved lube-oil feeding system; integrated balancer for 4-, 5-, and 6-cylinder engines (optional); PUP cancel valve (piston underside) ; and modified fuel injection system with standard variable i n j e c t i o n timing mechanism.
The impact of the changed priorities as a result of sharply increased fuel cost on the design of the RL series was very strong. Overall economy is now exploited on a much larger scale than hitherto, and waste heat recovery is an important aspect. As a result of outstanding development efforts, the fuel consumption rates of the loop-scavenged crosshead engine are now extremely low and quite competitive with other systems.
Reliability and simplicity, combined with optimum suitability for low-quality fuel, are the basic assets of this type of engine and will continue to be an extremely important aspect for marine propulsion machinery.
Claim was recently laid to probably one of the lowest specific fuel consumption rates for any long-stroke diesel engine built in series. A 4-cylinder Sulzer RLA 90 engine—converted to the RLB specification — is said to be the first such engine to break the 130 gram fuel barrier. With a specific fuel consumption of 129.1 grams per horsepower-hour, or nearly 3 grams under the guaranteed fuel rate for this series, this crosshead engine built by Sumitoma Heavy Industries in Japan has a maximum continuous rating of 13,600 bhp at 90 rpm. In its continuous effort to meet all the stringent future demands imposed on diesel engines f o r both marine and stationary purposes, Sulzer has now further developed its highly successful series of Z 40 medium-speed engines.
All the well-proven inherent advantages of the Z 40 engine design have been incorporated in the new engine, and maximum use has been made of the experience gained from the considerable number of service hours with heavy fuel. The outcome of this development is the ZA 40, one of the most technologically advanced, medium-speed engines on the market. Among other things, this design offers a greatly reduced specific fuel consumption, a better capability to burn lowquality fuels, a highly efficient and economical cylinder lubrication, a greater potential for efficient waste heat recovery, facilitated maintenance, and an increased output.
F o r a d d i t i o n a l information about these and other Sulzer diesel engines, TRANSAMERICA DELAVAL Transamerica Deiaval Enterprise R and RV medium-speed diesel engines operate in the range through 450 rpm, developing from 3,300 to more than 13,000 bhp at a bmep of 250 psig. The R and RV series is composed of 6- and 8-cylinder in-line engines, and Vee-form engines with 12, 16, or 20 cylinders. The bore is 17 inches (432 mm), the stroke is 21 inches (533 mm), and the output range reaches up to 677 bhp per cylinder.
An agreement signed recently with the Dutch firm of Stork- Werkspoor Diesel B.V. of Amsterdam gives Deiaval the rights to the exclusive manufacture and marketing of the Enterprise/ SWD TM 620 diesel. This engine, which operates up to 425 rpm, is offered as a 9-cylinder in-line unit with an output of 16,000 bhp at the flywheel, and a Vee type 12-cylinder unit rated at 21,700 bhp. The Vee type, rated at 1,800 bhp per cylinder, is soon to be rated at 2,000 bhp, giving it the highest medium-speed horsepower per cylinder rating in the world.
Recent installations reinforce Delaval's reputation as a leader in the marine power field. Four Enterprise RV-16 d i e s e l s will power two 35,000-dwt tankers being built by Bath Iron Works for Falcon I Sea Transport Company. The owner will charter the 666- foot vessels to the Military Sealift Command for transporting fuels to government bases worldwide. The RV-16s, each rated at 7,360 bhp, are designed to operate on various fuels including the more economical grades with viscosities up to 3500 Redwood.
The 36,000-dwt Pride of Texas, first of three dry bulk carriers being built by Levingston Shipbuilding Company in Orange, Texas, for Asco Falcon I, is powered by twin Enterprise RV-12 direct-reversing engines giving the ship a total of 15,600 bhp. The two sister ships will be similarly powered.
Delaval RV-16 diesels were the choice to power six 47,000-dwt Catug petroleum carriers. The barges are being built by Bethlehem Steel's Sparrows Point yard, and subcontractor Halter Marine of New Orleans is building the tugs. Each tug-barge unit is powered by twin direct-reversing diesels, each engine rated at 9,100 bhp.
Twin Delaval RV-16 engines propel U.S. Steel's 1,000-foot ore carrier, the Edwin H. Gott. A recent inspection of the main propulsion engines after the Gott's second year of service provided an opportunity to assess RV-16 durability after burning heavy fuel for 10,000 hours of service, two-thirds of that time at full power. According to the inspecting engineers' reports, pistons, cylinders, and cylinder heads showed very low wear rates; ash deposits were minimal, and internals of the engine were described as "exceptionally clean." A contract to supply ship service diesel generators for three American President Lines containerships under construction at Avondale Shipyards in New Or- leans marks Delaval's entry into the important auxiliary marine power area. The 860-foot vessels each will be equipped with three Delaval 2,500-kw DMR46, in-line medium-speed diesels, fully prepackaged with generators and auxiliaries. Compatability with heavy fuels, long a Delaval feature in its traditional role as builder of main propulsion units, was a key criterion in the engine's selection f o r auxiliary power.
For additional information on Delaval Enterprise engines, VOLVO PENTA Volvo Penta's line of diesels for commercial use consist of 2-, 3-, 4-, and 6-cylinder engines covering 12 different models. Some models are equipped with turbochargers and others with both turbo and after-coolers. Most are available with marine society certifications. Additionally, Volvo Penta offers twin engines driving through a compound gear providing a single shaft output from 336 shp to 580 shp. The twin engine/single output package provides many advantages including "take-home" capability on one engine.
A wide range of accessories designed for commercial use are available. Work-saving accessory items include front or side mounted power take-offs, flexible engine mounts and shaft couplings, freshwater filters, auxiliary alternators, engine-mounted pumps, and many more.
The heavy-duty Volvo line includes the model MD 120A, a 6-cylinder engine with maximum continuous rating of 168 shp at 1,800 rpm; the 6-cylinder TMD 120A with mcr of 260 shp at 1,800 rpm; and the 6-cylinder TAMD 120B with mcr of 328 shp at 1,800 rpm.
For additional information on Volvo Penta marine diesels, WARTSILA/NOHAB The Diesel Division of OY Wartsila A.B., Finland, comprises the Wartsila Vasa Factory in Finland and Nohab Diesel A.B. in Sweden. Its Nohab and Vasa engines are medium-speed, fourcycle diesels with an output range from 690 bhp to 8,250 bhp.
Wartsila has a long tradition in the design, development, and manufacturing of diesel engines. Due to the company's comprehensive product development, Wartsila engines already meet the requirements of the future in regard to burning low-grade fuel, good fuel consumption rates, and excellent service economy. The Wartsila engine line includes the following: The Vasa 32, with 12.60-inch bore and 13.78-inch stroke, is manufactured as in-line and Vtype versions with outputs ranging from 1,790 to 8,250 bhp. The Vasa 22HF engine, with 8.66-inch bore and 9.45-inch stroke, is offered in 4-, 6-, and 8-cylinder inline versions and in 12- and 16- cylinder V - t y p e configurations, with outputs of 710 to 3,410 bhp. The Nohab F30 type engine, with 9.84-inch bore and 11.81-inch stroke, is manufactured in 12- and 16-cylinder V-type versions; output range is from 1,745 to 4,025 bhp. The Vasa 24 type engine with outputs from 690 to 1,460 bhp is also available. The Vasa 32 and 22 type engines were designed and developed to operate on heavy fuel up to 380 cSt, whereas the Nohab F30 can accommodate fuel with a viscosity of 180 cSt.
Among the applications for Wartsila diesels are main engines in ships for both geared and diesel-electric propulsion, auxiliary engines for vessels, and generator systems for stationary power plants. The Vasa 32 provides an excellent combination as both main and auxiliary engine in the same ship, such as in car/ passenger ferries. This provides simplified maintenance routines and the advantage that all the engines can be operated on bunker oil.
The Nohab F30 is widely used in offshore vessels, and more than one million bhp is presently in operation on such vessels and on oil rigs.
The Wartsila Diesel Division recently set up a completely new engine factory in Singapore, in partnership with Keppel Shipyard. To be known as Wartsila Power Singapore, its principal product will be the Vasa 22HF engine family. Wartsila Diesel also has a wide network of its own representatives, agents, and service stations all over the world. In the U.S., sales are handled by Wartsila Power, Inc., Marrero (New Orleans) and the West Coast branch, Wartsila Power Seattle, Inc. Wartsila Power, Inc. provides 24-hour parts and service from its workshop/office in Marrero.
For additional information on Wartsila's Vasa and Nohab engines, WAUKESHA ENGINE Waukesha Engine Division of Dresser Industries announced this year that it will manufacture a new family of large-bore marine diesel engines under a license from Sulzer Brothers Limited of Winterthur, Switzerland.
The new engines, scheduled for production in 1982, will be called the AT25 series. They are rated from 1,230 to 4,320 maximum continuous bhp (985 to 3,223 kw) for propulsion and up to 3,040 kilowatts for ship's service electric sets at 1,000 rpm.
Available in four basic models —6- and 8-cylinder in-line &nd 12- and 16-cylinder Vee versions — the AT25 series engines will have a bore of 250 mm and stroke of 300 mm (9.84 by 11.8 inches) and are capable of operating on heavy fuel.
The V-16 model 16V-AT25 has maximum continuous ratings of 4,320 bhp at 1,000 rpm, 4,000 bhp at 900 rpm, and 3,520 bhp at 750 rpm. Its ship's service electrical ratings include 2,800 kw, 60 Hz at 900 rpm, and 3,040 kw, 50 Hz at 1,000 rpm. Maximum continuous ratings of the V-12 model 12V-AT25 include 3,240 bhp at 1,000 rpm, 3,000 bhp at 900 rpm, and 2,640 bhp at 750 rpm, with ship's service ratings of 2,100 kw, 60 Hz at 900 rpm, and 2,280 kw, 50 Hz at 1,000 rpm.
The in-line, 8-cylinder model 8L-AT25 has maximum continuous ratings of 2,160 bhp at 1,000 rpm, 2,000 bhp at 900 rpm, and 1,760 bhp at 750 rpm. Ship's service ratings include 1,400 kw, 60 Hz at 900 rpm, and 1,520 kw, 50 Hz at 1,000 rpm..
The smallest in the family, the in-line, 6-cylinder model 6L-AT25 has maximum continuous ratings of 1,620 bhp at 1,000 rpm, 1,500 bhp at 900 rpm, and 1,320 bhp at 750 rpm. Ship's service ratings are 1,050 kw, 60 Hz at 900 rpm, and 1,140 kw, 50 Hz at 1,000 rpm. Design features include rigid, one-piece cast crankcase and cylinder block with underslung crankshaft for greater stiffness. Bore-cooled cylinder heads with water-cooled valve seats permit operation on heavy fuels. The application of pulse type turbocharging provides excellent performance and fuel economy at part or full load.
In addition to the AT25 series, Waukesha offers two other families of engines. Its VHP marine diesels are the result of a 10-year design program to provide a reliable, high-performance engine for workboats and fishing trawlers in the intermediate horsepower range. Outputs range from 416 to 1,636 continuous bhp (310 to 1,220 kw) at 1,215 rpm.
Complementing the AT25 and VHP lines are the smaller midrange VS series marine diesels.
They are rated up to 348 continuous bhp (260 kw) at 1,900 rpm for propulsion and 235 kw at 1,800 rpm in ship's service generator sets.
For additional information on Waukesha marine diesel engines, WICHMANN DIESEL From a modest family-owned operation founded in 1903, the Wichmann firm has expanded continually, and today its plant is said to be one of the most modern in the world. The company's U.S. manufacturing facility is located in Kenner, La. near New Orleans.
During its first 30 years of operation, Wichmann built twostroke semi-diesel engines, then switched to two-stroke, full-compression ignition engine production around 1935. Since that time, the company has produced several engine models, increasing its size and horsepower range with each model change.
In the late 1960s, Wichmann introduced the AX and AXG series of in-line engines, which were forerunners to the current engine type, the A X A and the AXAG. The AXA engines are coupled directly to the propeller shaft through an integral hydraulic clutch, as these engines have a relatively low speed of 375 rpm. The AXAG engines operate at higher speeds, 475 rpm, and are normally equipped with reduction gears that are available with an infinite number of ratios. The output of the AXA and AXAG models ranges from 1,350 to 4,000 bhp, and engine configurations range from four to 10 cylinders.
All Wichmann engines are of a simple single-acting, two-stroke cycle, liquid-cooled design, and all are turbocharged, intercooled, loop-scavenged, and direct-injected. The scavenging process is timed by inlet and outlet ports in the cylinder liners, so there are no valves or valve-operating mechanisms. All major components are of modular construction. Accessories are driven by gear trains located at both ends of the engine.
This design provides a sturdy, reliable engine that requires a minimum of maintenance and is simple to repair. For example, the removal of four nuts permits removal of a cylinder head.
The absence of valves and the valve train eliminates one of the major causes of diesel engine failure.
Overall, experience has shown that the ratio of operating hours to maintenance hours is higher and economical for the operator. Complete interchangeability of parts between engine types and a smaller onboard inventory of spares reduces maintenance support problems and storage requirements, which frees operating capital. With fewer moving parts and low engine speeds, engine wear is said to be reduced substantially, and lube oil lift extended. In other areas of economy, fuel utilization is said to be extremely low — one of the p r i m a r y application considerations today — and intermediate fuels have always been available in Wichmann systems as a viable alternative to marine diesel oil. Considerable research, development, testing, and e v a l u a t i on have resulted in an engine design that provides one of the lowest fuel consumptions in the world, specifically, 0.3417 pounds per bhp hour. This translates into approximately 0.046 gallons per bhp hour. In practice, the Wichmann 4AXA, which is rated at 1,350 bhp, would consume approximately 63 gallons per hour at full load.
It is common practice today, however, to purchase a propulsion system that provides approximately 120 percent of the required load, permitting the system to be operated at 80 percent load. This reduced loading enables the engine to be operated in the optimum portion of the fuel consumption curve.
F u n c t i o n a l l y , the Wichman scavenging system, low engine speed, and long stroke provide t h i s i n c r e a s e d fuel efficiency, which also results in a more uniform and complete combustion process, utilizing all of the fuel that is injected for the propulsion of power rather than smoke generation. This also minimizes carbon deposits, especially in intermediate fuel applications.
In the near future, a Wichmann V engine will become part of the engine family. The V engine is now in the final stages of test and evaluation. When production models are available, the engine series will provide a power range of from 1,800 to 4,800 bhp, with configurations from six to 16 cylinders.
For additional data and free literature on Wichmann engines,