September 2004

A new generation of SCHOTTEL Transverse Thrusters

SCHOTTEL has developed a new series of transverse thrusters, based on more than 50 years of experience in the field of propulsion and manoeuvring systems. The new types STT 1, 2, 3 and 4 are a further development of the tried-and-tested types STT 330, 550, 1010 and 1212. This new series covers the power range from 600 kW up to a maximum of 1400 kW. Both controllable-pitch and fixed-pitch propeller versions are available.

The objective of this new development was to meet even more fully the specific demands of operators, yards and owners. The main improvements are:

  • Very compact design
    (e.g. reduction of the tunnel length and higher power concentration at the propeller, thus making smaller propeller diameters possible)
  • Well-adjusted reduction ratios for four-pole electric motors
  • Special reduction ratio available to reduce the peripheral speed of the propeller blades in order to minimize noise levels for special applications
  • Introduction of newly-developed technologies, such as the LEACON sealing system
  • Additional reinforcement and stiffening plates in the main body of the tunnel to simplify installation of the transverse thrusters at the shipyard and to minimize undesired vibrations.

In order to reduce running noise as far as possible, SCHOTTEL specially designs each individual transverse thruster propeller for the specific customer application and using a back-skew design. SCHOTTEL also offers the option of isolating the entire bow thruster elastically from the vessel’s hull.

Propeller blade pitch control systems for CP transverse thrusters are available with DP, AP and VDR interfaces. These modules allow us to meet the high demands of, for example, offshore operators in terms of reliable position keeping of their vessels even in rough weather conditions.

As a special feature, our new transverse thruster generation can be equipped with the LEACON sealing system. This technology allows monitoring of the propeller shaft seal package during operation by observing the gap between the oil seal and the water seal for possible leaks.

Optionally, a special seal can also be fitted to keep sand or similar particles away from the actual seal package. This seal is a development that is in successful day-to-day operation in our Pump-Jets, predominantly in shallow-water conditions. The optional fitting of rope-cutters, to prevent damage to the seals from fishing lines, for example, rounds off the range of possible variants.