Research and Development

CJR's philosophy is to never rest on its laurels and to continually strive to remain at the forefront of propeller design and manufacturing technology. The industry continues to move forward particularly with advances in marine diesel technology and boat construction techniques.


CJR - CFD research and development

To this end we have an ongoing ‘no compromise’ Research and Development programme constantly evaluating and advancing our propeller designs to improve performance, efficiency and smoothness of operation. In addition, and equally as importantly, the R&D programme extends to our manufacturing practices where we continually adopt new techniques and invest in new machinery.

Advanced Propeller CFD

With increased computational power available, we are now capable of performing transient CFD analysis of our propellers. This state-of-the-art approach allows us to get much more insight into the details of the flow around the propulsor, study its interactions with the hull and sterngear, as well as analyse the pressure variations they induce. As a basis design tool this method would be too computationally intensive to fit within the timescales of the market we operate in. However, it provides an excellent means of providing invaluable data for our unique projects, supporting the development of new propeller series and complementing our current approach when conducting the final design calculations.


Propeller Design

Using a unique and highly complex software programme developed for CJR  at the CTO in Gdansk incorporating Lifting Surface Theory and integrated with Computational Fluid Dynamics (CFD), we are able to test our designs in a virtual world that replicates real world conditions. This enables us to gather valuable data before validating the designs using models in laboratory tests and finally in full size sea trials. The ability to electronically recreate real world conditions, and to predict performance with incredible accuracy, dramatically speeds up the design process. This ‘appliance of science’ does away with the traditional trial and error approach so typical of the industry.


Manufacturing R&D

We make extensive use of state of the art CNC machinery in the manufacture of our shafts and stern gear. We now have the capability to fully CNC machine our propellers on our 5-Axis machining centre; the ultimate method for reproducing a perfect finish every time and with absolute accuracy. In order to get the best out of this phenomenal machine, we have developed bespoke integration software using visual recognition technology. Much of the technology we utilise is developed in the aerospace industry where quality and accuracy are the number one considerations and compromise is simply not an option. The benefits of this dedication to research and development are many and varied, but include:- 

  • Improved performance, responsiveness and manoeuvrability
  • Smoother running and quieter operation
  • Improved efficiency
  • Longer working life for the whole shaft line and drive train
  • Increased range
  • Reduced emissions
  • First trial acceptance
  • Faster turnaround from concept to reality
  • Bearings

    Suitable bearings are required in stern tube and rudder tube assemblies.

  • CJR Propellers

    Every boat is different and the first sign of this difference can be seen in propeller operation.

  • Couplings

    Couplings are the elements that transfer torque from gearbox to the shaft and because of their role they are under strict supervision of class societies.

  • Ducted Propellers / Nozzles

    CJR can offer ducted propellers systems including any type nozzles and impellers under full IACS approval.

  • Rudder Tubes Assemblies

    CJR manufactures rudder tube assemblies designed for hull trough installation to suit stock diameter from 30mm up to 180mm.

  • Rudders

    Rudder profile and sections are carefully selected to specific regime of the flow around sterngear.

  • Shaft Brackets

    Our shaft brackets are designed bespoke to achieve optimum performance in line with every vessel individual requirements.

  • Shaft Seals

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  • Shafts

    Shaft design starts from designing entire shaftline incorporating all the components from the propeller to the gearbox and including the bearings to make the system safe, vibration free and efficient in operation.

  • Stern Tubes / Shaft Logs Assemblies

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  • Tie Bars

    Tie bars connect both rudder tillers on twin rudder boats to simply synchronise them together.

  • Tillers

    Tiller is important part of steering gear which design is covered by strict rules of classification societies when the boat is built under class.

  • Shaft Alignment

    Using laser technology and precision engineering a bespoke shaft alignment tool has been developed to aid the boat builder’s task of accurately fitting and aligning the stern gear.

  • PropSmith

    For the fast, simple and precise installation and removal of propellers, PropSmith is the professionals’ choice.

  • TrialDAS

    TrialDAS is a new data acquisition system specifically tailored for monitoring sea trials. The system is based on rate gyros, GPS, accelerometers and magnetic field sensors to record every movement of the boat.

  • Keyless Hub Hydraulic Kit

    Quick and convenient method of pushing and releasing large propellers or couplings to and from the keyless shaft cone.

  • Hydraulic Propeller / Coupling Pusher / Puller

    Quick and convenient method of pushing and pulling propellers or couplings to and from keyed shaft end.

  • TrialsAPP

  • Quality Policy

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  • Design

    We don’t only make propellers, we analyse entire propulsion system of each boat starting from hull resistance prediction and hull propulsive factors.

  • Pattern Making

    Precise pattern assures high accuracy of final product and it is one of the most important stages in manufacturing process

  • Casting

    CJR's foundry team has the combined benefits of over 150 years experience in the industry.

  • Machining

    CAD/CAM controlled machining of the cast propellers, P brackets and rudders are undertaken to the fine tolerances of their original design

  • Finishing

    Our processes ensure that the geometry of our finished castings is always true and accurate to the original design.


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CJR Propulsion Ltd
70-72 Quayside Road
Bitterne Manor
SO18 1AD
United Kingdom

Tel: +44 (0)23 8022 2032
Fax: +44 (0)23 8021 1832