Page 40: of Maritime Reporter Magazine (October 15, 1981)

Diesel Power Review —Stork-Werkspoor (continued from page 42)

TM 620, has entered service in a number of main propulsion ap- plications. A single V-form, me- dium-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 con- tinues to concentrate its research and development efforts in this area. Developments are made con- stantly 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 de- signed and developed to run on heavy fuel. As a consequence, only small adaptations are neces- sary 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,

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SULZER

The modern Sulzer RL cross- head diesel engine range, contain- ing the RL 56, RL 66, RL 76, and

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Beam 40

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RL 90, is now complete. This com- pletes the development of a loop- scavenged, low-speed engine se- ries under very largely changed conditions, where the priorities have been dominated by fuel econ- omy and fuel quality aspects.

In the past, the development of two-stroke diesel engines has had two major priority aspects: in- crease 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 per- cent and, despite a large increase in firing pressures of approxi- mately 55 percent, the reliability was improved substantially as a result of unprecedented develop- ment efforts.

The oil crisis in 1973 had a tremendous impact on the phi- losophy of engine design and de- velopment. 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 en- gine designer.

Major features of the RL type engine include: new type of tur- bocharger with increased effici- ency and pressure ratio range; foundation bolts arranged in one row on the outside; bedplate with integrated thrustblock; single columns; one-piece gear column; simplified scavenge air receiver; one-piece, bore-cooled cylinder cover with eight bolts; bore-cooled (water) piston crown; bore-cooled cylinder liner; enlarged crosshead pin with improved lube-oil feed- ing system; integrated balancer for 4-, 5-, and 6-cylinder engines (optional); PUP cancel valve (piston underside) ; and modified fuel injection system with stand- ard variable injection timing mechanism.

The impact of the changed pri- orities as a result of sharply in- creased 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 re- sult 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, com- bined with optimum suitability for low-quality fuel, are the ba- sic assets of this type of engine and will continue to be an ex- tremely important aspect for ma- rine propulsion machinery.

Claim was recently laid to prob- ably 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 (continued on page 47) 14

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