Page 50: of Maritime Reporter Magazine (July 15, 1986)

PROPULSION

UPDATE sor and two-stage, gas-coupled pow- er turbine.

The 570-KF was first used for boost propulsion on the ocean yacht

Shergar. In this application a pair of 6,500-shaft-horsepower 570-KFs drive through high-speed clutches into a combining gearbox. Finally, a 10,000-kw waterjet provides the propulsion. This 240-ton fast yacht has the capability of 50+ knots with the gas turbine/waterjet propulsion system.

The Swedish Navy has also se- lected the 570-KF for boost propul- sion on their Spica III "Stockholm" class fast patrol boats. In this case the drive system uses a single stage epicyclic reduction gear and a 15- t degree vee-drive to turn a controlla- ble-pitch propeller. The 320-ton- ghp hull vessel has a boost speed of 38 knots.

The Allison Gas Turbine Division of General Motors has extended its product improvement efforts to the 501-KF and 570-KF marine gas tur- bine engines for increased reliability and maintainability of these high- power density, simple-cycle units. 501-KF

The 501-KF engine is successfully used in the Boeing "Jetboil" passen- ger ferry. The arrangement is a 501-

KF engine on each side of the vessel driving a Rocketdyne PJ20 waterjet.

The engines develop 4,330 contin- uous shaft horsepower each and are available with various improve- ments to enhance their capability.

Recent options released to the 501-

KF include: • Split Outer Combustion Case—

Allows access to combustion liners without engine removal. • Low Emission Combustion Lin- ers—Combines the need for low emissions with improved life through optimizing flame profile and thermal barrier coatings. • Closed Loop Electronic Con- trol—Improves fuel system per-

Allison Implements Performance,

Maintenance, Reliability Improvements

In Marine Gas Turbines formance by integrating speed and turbine gas temperature to provide stable efficient power. • Turbine Gas Temperature measured at Interstage Point—In- creases thermocouple life.

The engine is also employed as a single prime mover on the Grum- man M161, 105-ton hydrofoils. This application uses bevel gearing for reduction and drives a single propel- ler for speeds up to 52 knots.

MARINE GAS TURBINE PERFORMANCE SUMMARY 100 DEC F AMBIENT TEMPERATURE * INCH INLET LOSS 6 INCH EXHAUST LOSS

LIQUID FUEL operating point is shown at .505 lbs/ hp-hr and 4,500 hp, under these conditions. Also, the engine is capa- ble of operating on LPG or LNG for tanker applications although the typical marine application is with #2 diesel fuel. 570-KF

The 570-KF is a 6,350 nominal horsepower marine gas turbine uti- lizing a variable geometry compres- 570K ENGINE OPERATING TIME

Since introduction of the 570-K engine, Allison has continued its product improvement efforts to in- crease the service life of this single- spool, simple-cycle engine. High- lights of this program include: • Compressor Blade Manufacturing

Process—Application of electro- chemical machining techniques have eliminated subsurface defects caused by roll-forming blades. This change has eliminated early fatique failures in blades.

The 501 has exceeded 12-million hours of operating time in industrial ?§ and marine service. Mean Time Be- f| tween Overhaul is, of course, depen- || dent on duty cycle, and the 501-K engines have achieved intervals of 12,000 hours in certain applications.

The fuel economy of the engine is shown in Figure 1 for Standard U.S.

Navy conditions. The maximum 50 Maritime Reporter/Engineering News