Becker Marine Systems, Hamburg


 Today, Becker Marine Systems is market leader for high performance rudders of all kind of profiles and all sizes. Worldwide representation with our own offices and more than 20 agencies.

In 2002 Becker Marine Systems widened its product range with the introduction of the Automated Material Handling System. In March 2003 the Schilling rudder business was acquired, thus allowing the creation of a dedicated UK office. The Becker worldwide network has been further enhanced in 2003 with the establishment of a China office, together with the relocation of the Company Headquarters to purpose built offices in Hamburg.

Rudder Systems

The traditional Becker rudders with KSR (King Support Rudder) bearing guarantee best possible maneuverability of your vessel with lowest possible fuel consumption. These are the advantages:

  • Optimum balance and flap area
  • Minimum additional resistance induced during maneuvering
  • Minimum size of steering gear
  • Highest securing against flexural vibration
  • Best values of natural vibration
  • Highest safety against cyclic stresses
  • Maximum security in case of damage
  • Durable in ice
  • Easy maintenance of link system

         Besides the BMS flap rudder types many vessels and owners call for conventional rudders. Those conventional rudders are placed behind the propeller with the rudder cross section arranged symmetrically with the rudder centre plane. However this arrangement does not consider the fact that the propeller induces a strong rotational flow that impinges on the rudder blade. This results in areas of low pressure on the blade that can induce cavitations and associated erosion problems. To avoid cavitations and to improve the maneuverability performance of a full spade rudder, Becker has developed the twisted leading edge rudder types.

Schilling® KSR

The Schilling® Rudder is a high lift rudder, designed for vessels of any size, and supplied in single or multiple configurations. Recent extensive Computational Fluid Dynamics (CFD) work led to an improved Schilling® Rudder profile. The CFD research was part of the development of the new Schilling® KSR and Schilling® Navigator Rudder systems. The improved profile enhances the advantages of the Schilling® design:

  • Reduced drag at full scale
  • Preserves the already excellent lift characteristics
  • Moves the main thickness of the section aft to house the KSR bearing

All calculations were performed at full scale and proved a rudder drag reduction at normal cruising helm angles by approx. 25%, with the lift (side force) identical to the original section. A new concave streamlined fishtail is incorporated, which improves the flow separation characteristics compared to previous fishtail designs. Also, the main thickness of the section has been moved further aft, eliminating the requirement for additional strength ‘bulges’ for faster vessels and/or cases with highly loaded propellers. Further research work with particular emphasis on the leading edge performance under heavy propeller load resulted in an optimised profile, the detailed end-plate optimisations are carried out individually to suit particular operational scenarios.

 


A new family of Schilling® profiles has been created which have been optimised through intense research with Computational Fluid Dynamics techniques and confirmed by model tests. The new profiles have opened the possibility to incorporate Becker’s proven KSR (King Support Rudder) bearing support arrangement. This new Schilling® KSR Rudder is primarily intended for application to larger, slower vessels such as tankers and bulk carriers, although in principle it is suitable for application to any type of vessel. The new rudder product is unlimited in size and offers superior manoeuvring performance.

Kort Nozzle Systems

Examples of suitable ship types:

  • Tug boats
  • Push boats
  • Supply vessels
  • Fishing vessels
  • Research vessels
  • Special ships and many more

Advantages:

  • Increased bollard pull Increased thrust
  • Better propulsion efficiency
  • Better steerage capacity
  •  Reduced vibrations
  •  Protection of propeller against damage
  • Reduced operation costs – fuel saving

Becker Mewis Duct®

The Mewis Duct® is a novel power-saving device which has been developed for full-form slower ships that allows either a significant fuel saving at a given speed or alternatively for the vessel to travel faster for a given power level. The Mewis Duct® consists of two strong fixed elements mounted on the vessel: a duct positioned ahead of the propeller together with an integrated fin system within. The duct straightens and accelerates the hull wake into the propeller and also produces a net ahead thrust. The fin system provides a pre-swirl to the ship wake which reduces losses in propeller slipstream, resulting in an increase in propeller thrust at given propulsive power. Both effects contribute to each other. The achievable power savings from the Mewis Duct® are strongly dependent on the propeller thrust loading, from 3% for small multi-purpose ships up to 9% for large tankers and bulk carriers. The power saving is virtually independent of ship draught and speed. The Mewis Duct® is ideally suited to both new-build and retrofit applications (e.g. Tanker, Bulker MPC).

Fuel saving up to 9%
Low NOX and CO2 emission
No moving parts

How does it work?

High blocked ships have low propulsion efficiency. The reasons are the bad wake field and the high propeller loading. The water inflow has such an unfavourable characteristic that the propeller is working in bad inflow conditions. The Mewis Duct® harmonizes and stabilizes the flow and generates a preswirl to reduce the rotional losses in the propeller slipstream.

The integrated fins have a stator effect by generating a preswirl in counterdirection of the propeller operation. This generates more thrust. The fins are asymmetrically profiled and arranged to generate a perfectly homogenous flow distribution.

Consequent propulsion improvement can only be achieved if several aspects of hydrodynamic performance are taken into account. The combination of the Mewis Duct® with a corresponding Becker Rudder dramatically increases the efficiency of the system by means of of wake field optimization and less rudder resistance at improved menoevring performance.

 

 For more detailed information about Becker Marine Systems click here...