Adaptable Z-drive thruster system enhances station keeping

March 1, 1995

Anchor handling tugs face a wide range of demands - heavy towing, free running, station keeping and manoeuvring with little room for error. A versatile propulsion system is needed to meet these different needs. Lars Larberg, KaMeWa's project manager for propulsion systems, believes the company's new Mark IV Z-Drive Thruster is the answer.

Anchor handling tugs face a wide range of demands - heavy towing, free running, station keeping and manoeuvring with little room for error.

A versatile propulsion system is needed to meet these different needs. Lars Larberg, KaMeWa's project manager for propulsion systems, believes the company's new Mark IV Z-Drive Thruster is the answer.

One of the drive's key features is its enhanced station-keeping capability, made possible by the fine control of thrust. This is achieved by means of an internal multi-disc clutch which allows the running of the propeller all the way down to zero rpm. Normally external rpm control devices are required as the drive system itself cannot take the rpm below the engine idling speed.

The clutch forms an integral part of the system, rather than being separately mounted in the shaft line as is the case in other Z-drives. The KaMeWa drive is also adaptable to the rpms of various diesel engines. By selecting the gear ratio, the system can handle the whole range covered by diesel engines from 600 to 1,800rpm

KaMeWa's new Mark IV Z-Drive thruster.

360° turning

As regards manouevrability, the azimuth steering system allows the thruster to be turned through 360 and the thrust to be directed at any angle. The simplified azimuth bearing consists of a cross-roller bearing with its outer part connected to the hull and its inner part to the thruster.

The thruster is controlled by the Newman system, KaMeWa's own microprocessor-based control system. The hardware comprises standardised modules type approved by all major classification societies, while the software is custom-made for the Z-drive requirements and includes rotation control, clutch control and rpm control. These three functions are exercised through one hand lever.

Larberg believes the company has achieved a competitive price for the Z-drive thruster by offering it as a complete package, ready for installation. KaMeWa can also undertake the installation, including the connection of the thruster to the diesel engine.

For more information contact Olof Malmquist, KaMeWa: telephone +46 550 84000 or fax +46 550 18190.