Page 27: of Maritime Reporter Magazine (April 1994)

Effjohn's Finnjet was ordered to receive a CODELAG gear system of Renk-Tacke design.

Renk-Tacke Supplies Gear Units For

Retrofit Of Finnjet Superferry

In spring 1993, Renk-Tacke,

Augsburg, received an order from the Finnish group Effjohn Oy AB, which includes Silja Line and oth- ers, for the delivery of a completely new gear unit system valued at approximately $68.24 million to be retrofitted in the superferryFinnjet.

The Finnjet is reportedly the world's largest commercial gas tur- bine-powered vessel (25,900 grt).

This fast ferry runs between

Travemunde and Helsinki all year round with a maximum speed of 30 knots and a crossing time of only 22 hours.

The CODELAG gear system (COmbined Diesel-ELectric And Gas turbine) can be run in three differ- ent modes: diesel-electric, gas tur- bine only or in combined operation, depending on the required ship speed. To minimize fuel consump- tion, the most favorable propeller speed is obtained by using three different gear ratios on the electric drive side.

The two gear units — with a weight of approximately 90 tons — transmit a total power of60,000 kW to two controllable pitch propellers by way of a three-stage gear; each gear stage using double helical, case hardened and ground gears to achieve a maximum propeller speed of 176 rpm. The gear system is rated according to Det Norske Veritas's (DNV) highest ice class "1A super" rating. The gear units will be sup- plied this month after a design and build period only 13 months and a test of the system on March 4. The exchange of gear systems must be completed with a basic overhaul period of 14 days. The completely assembled gear units will therefore be transported along the car deck to directly above the engine room and then lowered in place by means of special lifting equipment.

The options offered by the gears will reportedly allow very economi- cal cruising, and the main wheels were treated by Renk-Tacke's "SLE" procedure to minimize noise. Renk-

Tacke says the structure-borne sound limit curves that can be achieved are comparable to those of frigate gear units.For more infor- mation on Renk-Tacke,

Circle 161 on Reader Service Card

BEST VALUE FOR MONEY"

ASTANO

P.O. BOX 994 15080 Ferrol

La Coruna - Spain

Tel. (3481) 34 3211

Fax (3481) 34 3252

ASTANDER

P.O. BOX 10 39080 El Astillero

Cantabria - Spain

Tel. (3442) 54 0050

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P.O. BOX 39 11080 Cadiz

Spain

Tel. (3456) 27 3350

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Renk-Tacke's CODELAG gear system for theFinnjet offers three modes of operation: diesel-electric only, gas turbine only, or a combination mode.

April, 1994 29