Renk Tacke Wins Planetary Gear Unit Order From Mitsubishi

The German corporation of Renk Tacke, a subsidiary of MAN B&W, has won an order from Mitsubishi Heavy Industries (MHI) to build the largest marine planetary gear unit the company has yet produced. The unit is intended for a VLCC tanker which will be equipped with two contra-rotating propellers. Both propellers are to be arranged co-axially and driven by a low-speed diesel engine of 20,600 kw power (28,000 HP).

The contra-rotating propeller has been a known principle for approximately 150 years, primarily being utilized for outboard motors or for naval torpedo applications. However, in 1983 Japan contracted out a study to explore the possibilities of using such drive systems onboard merchant vessels. This was closely followed by the construction of a 4,000-kw (5,400-HP) car-carrying vessel in 1988.

The results of the study sponsored by the Japanese concluded that even larger merchant vessels could be equipped with such drive systems. The advantages were as follows: • Fuel savings of up to 20 percent (with the above car carrier 13.5 percent of energy savings were attained on average).

• The reduction of environmental pollution due to reduced fuel requirements.

• As to the maneuverability, improvement of course stability became obvious with regard to the directional stability of the vessel. • Low noise and vibration development. Several years ago, Renk Tacke was supplying 13,000-kw (18,000 HP) marine planetary gear units for container vessels. The largest marine gear unit ever built by Renk Tacke transmits a power value of 46,000 HP.

For additional information on Renk Tacke and its marine planetary gear units,

tanker diesel engine outboard motors requirements A & B Industries stability R&R Marine vessel company service construction naval development power engine order energy container diesel corporation carrier results industries pollution onboard japan