Page 29: of Maritime Reporter Magazine (July 1990)

Diesel Power Review (continued) tem, if required) by the 1,280-kw diesel auxiliary unit. The shaft driv- en generator drives as a motor (PTI) the variable pitch propeller with nominal speed and reduced pitch.

The ship's power supply is provided by a harbor diesel.

Two cruise ships being built at

Rauma Shipyard for Discoverer

Reederei GmbH of Bremen, West

Germany, will each be fitted with two Krupp MaK model 8M 453C diesels and two 6M 332C engines.

The two larger 8M 453Cs, rated at 2,940 kw (3,943 bhp) each at 600 rpm, will provide main propulsion, while the smaller 6M 332Cs, rated at 1,200 kw each (1,609 bhp) at 900 rpm, will provide auxiliary power.

Of particular note is that both the main and auxiliary engines operate on heavy oil IF 380. With these two vessels, now there are 30 "One Fuel

Ships" with Krupp MaK engines.

In addition, the main and auxilia- ry engines are provided with resil- ient mountings to reduce the struc- ture-borne noise as much as possi- ble, a priority on board cruise ships.

MAN B&W DIESEL

Circle 76 on Reader Service Card

More than 100 engines developing a total of 1 million horsepower have been sold in the newly-formed fami- ly of MAN B&W Diesel medium- speed, four-stroke diesel engines.

This is convincing proof of the early success of the new family, which consists of the three in-line models

L40/54, L48/60 and L58/64 in the power output range of 5,300-16,300 hp.

The design principle behind the engine family—a concept which represents a consistent response to the demands of the operators of freight and passenger vessels—has proved its soundness in more than 600,000 hours of operation. A num- ber of original- and license-built plants have accumulated in excess of 30,000 operating hours.

The wear and lube oil consump- tion rates now available in a consid- erable body of figures confirm the soundness of MAN B&W's design considerations and expectations re- garding the service lifetime of the key components.

Liner wear at top-dead-center po- sition of the first ring is in the area of between 0.01-0.02 mm/1,000 hours. The wear of the first ring lies in the range of between 0.01-0.02 mm/1,000 hours.

Based on this, the lifetime of the liner can be calculated to be approx- imately 80,000 operating hours and for the first ring about 12,000 oper- ating hours. In the case of the piston rings, it proved possible to even exceed these expectations in 58/64 engines in some cases.

The lube oil consumption rate showing consistently low values in the range of 0.7-1.0 g/kwh (0.5-0.7 g/hph) after more than 30,000 oper- ating hours, also confirms the soundness of the design concept of

MAN B&W's medium-speed en- gines.

The method of cylinder lubrica- tion employed by MAN B&W has played a major role in achieving these favorable wear and lube oil consumption rates. This method of cylinder lubrication brings the cor- rect volume of oil to where the oil is needed at the correct time. The result is cleanliness and perfect functioning of the ring package, even after lengthy operating peri- ods.

Even at ignition pressures in the range of 160 to 180 bar in the L40/54 and L48/60 engines, a composite piston featuring a GGG piston skirt results in optimum piston running behavior and in a very low level of coke deposits at the fire lands.

Based on the experience to date with MAN B&W's state-of-the-art series of medium-speed four-stroke engines indicates that the service lifetimes of the key components first targeted have been achieved, and in some cases, surpassed. The picture emerging is that, with the

MAN B&W design concept, it has been possible to achieve these val- ues despite the firing pressure level.

In fact, most of the service intervals lie within the range of time intervals between two dockings sought by operators.

With the exception of the piston rings and the injection nozzles, the lifetimes of all major components are in excess of 20,000 operating hours.

No doubt it is that these figures are dependent upon the variety of conditions the engine is operated in and whether or not it has been well maintained. All the claims made above assume that the requirements laid down by the manufacturer for service, maintenance, operating me- dia, etc., have been adhered to rigid- ly.

In addition to long component life and long maintenance intervals, a simple, and, to the greatest possible extent, fault-excluding maintenance concept, possibly in connection with an effective diagnosis system, make a significant contribution to the overall economy of the engine plant.

Based on the accumulated data, the new MAN B&W Diesel engine family has established new stan- dards of excellence.

MTU

Circle 77 on Reader Service Card

In late 1989, MTU introduced its

TE-designated split-circuit cooling system which now has been applied across the range of the company's popular Series 396 marine diesel en- gine program.

The most important feature of the TE designation is a controlled, internal charge-air cooling system (using engine coolant to cool the charge air), which adapts the tem- perature of the combustion air to match the various operating condi- tions. At idle and during low-load operation, the charge-air tempera- ture is kept high, while in the me- dium- and full-load ranges, high en- gine power output with uniformly low thermal loading is ensured.

This coolant-temperature varia- tion is achieved through the use of a thermostat which alters the amount of coolant passing through the heat exchanger. At full power, the entire flow of charge-air coolant is directed through the heat exchanger—the temperature drops from approxi- mately 85 degrees C to 50 degrees C (185 degrees F to 122 degrees F). At idle speed, the coolant bypasses the heat exchanger and remains at the engine outlet temperature of ap- proximately 75 degrees C to 85 de- grees C (167 degrees F to 185 de- grees F).

As already employed in MTU's

Series 183 engines, Series 396 TE engines use plate-core heat ex- changers rather than traditional tube-type units. As the plates are constructed of titanium, they are both light and corrosion-resistant.

And, since raw (sea) water no longer passes through the intercooler, cor- rosion and resulting leaks are elimi- nated. Additional advantages in- clude improved heat-exchanging characteristics and ease of mainte- nance, as the plates are easily acces- sible for disassembly and cleaning.

Additional improvements to the

TE engines are provided by MTU's

R 082 electronic governor, a torsion- ally resilient steel-spring coupling (Geislinger system) and MTU's se- quential turbocharging, which adds or deletes turbochargers depending on the amount of power required.

The oil system, exhaust system and crankshaft bearings also have been subjected to further design develop- ments.

MTU Series 396 TE engines are rated from 680 kw (925 hp), the model 8V396TE64 engine, to 2,240 kw (3,050 hp), the 16V396TE94 unit. Of special note for applications with higher horsepower require- ments, MTU will continue to pro- duce the 12V396TB94 (1,920 kw/ 2,610 hp), the 16V396TB84 (2,240 kw/3,050 hp) and the 16V396TB94 (2,560kw/3,480 hp). A complete list- ing of MTU marine diesel engines from 52 kw/71 hp to 7,400 kw/10,060 hp is available from MTU North

America.

PAXMAN DIESELS

Circle 78 on Reader Service Card

Paxman Diesels Ltd., one of the

United Kingdom's principal manu- facturers of high-power, high-per- formance diesel engines, has been a major supplier to the British Royal

Navy for well over a half century.

Paxman has supplied low mag- netic signature marine diesel en- gines for the Sandown Class single- role minehunters, developed and built for the Royal Navy by the

U.K.'s Vosper Thornycroft. These

GRP-hulled vessels are each pow- ered by two Paxman Valenta 6RP200E propulsion engines. These

Valenta six-cylinder engines, which were chosen for their overall reli- ability, economy of operation and high-shock resistance, have a con- tinuous rating of 500 kwb (670 bhp) at 1,200 rpm. When installed in minesweepers, the power rating of these engines is raised to 755 kwb (1,012 bhp) at 1,460 rpm.

The advance of magnetic signa- ture ranging techniques has allowed the basic Paxman Valenta engine to be developed for MCM applica- tions. Significant advantages are gained in using Valenta RP200E en- gines for MCMs, according to Pax- man, including: extended periods between overhauls, increased reli- ability and ease of maintenance.

These are all major factors when considering propulsion machinery for MCM vessels.

The RP200E is available in six in- line and 8- and 12-cylinder V config- urations, with continuous ratings from 560 kwb (750 bhp) at 1,000 rpm up to 1,510 kwb (2,024 bhp) at 1,460 rpm.

In other work for the British

Royal Navy, Paxman has provided diesel power modules for the com- bined diesel and gas turbine (COD-

LAG) propulsion system in the new

Type 23 Antisubmarine Warfare frigates. Twelve of these ships are now under construction or on order.

The first of the class, the HMS Nor- folk, is due to be commissioned shortly.

Four Paxman Valenta 12RP200CZ power modules each having a continuous power output of 1.3 mw 440/600 v at 1,200 rpm, provide the power for the propul- sion system and ship's electrical supplies aboard each frigate.

Besides its work on Royal Navy

MCMs and frigates, Paxman has supplied diesel engines to more than 50 navies from around the world.

STEWART & STEVENSON

Circle 129 on Reader Service Card

Stewart & Stevenson Services,

Inc., with branches in Harvey, La., and Houston, Texas, is one of the world's largest distributors of De- troit Diesel and General Motors-

EMD engines from 50 to 4,300 hp.

With a normal inventory of hundreds of diesel engines and gen- erators, a staff of experienced me- chanical, electrical, and marine en- gineers, along with 24-hour world- wide parts and service, Stewart &

Stevenson offers an excellent sup- port network to its customers.

Full service branches, two reman- ufacturing plants, and over 200 dealers are ready to provide full ser- vice to customers, from financing a vessel to training and technical sup- port.

Stewart & Stevenson can provide custom-engineered power systems for all marine applications.

SlILZER DIESEL

Circle 6ti on Reader Service Card

Sulzer Diesel Ltd. is the new name for the diesel engine company of Sulzer Brothers Ltd. The decision to change from MBS Diesel Engines

Ltd. arose early this year when the

West German Government vetoed the proposed takeover of the com- pany's diesel engine activities.

Sulzer Brothers Ltd. will adhere to its strategic intention of seeking a partner to participate in its diesel engine subsidiary. Sulzer Diesel

Ltd. is continuing diesel activities as before and maintaining the same high level of research and develop- ment.

Sulzer Diesel recently introduced a new low-speed engine type, the

RTA84C, tailored for large contain-