CJR Propellers

Every boat is different and the first sign of this difference can be seen in propeller operation. The propeller is the most sensitive part of the boat that can sense any differences in displacement, trim, appendages set-up and engine performance as well as trial conditions like sea state, wind and everything around that can influence the boat performance. That is why CJR treats every boat separately and every propeller is selected carefully to the boat loading condition, most often custom made to the boat. This can be done using advanced CFD software to provide the perfect propeller for any boat design. The software includes accurate predictions of cavitation, and provides a good indication of the noise and vibration that will be felt by a propeller. Please read more about design procedure in Manufacturing/Design tab.

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For keyed hub-shaft connections CJR offer a hydraulic pusher/puller for quick and simple coupling and propeller attachment as well as Propsmith, a mechanical system for easy propeller fitting and removal.

Keyless shaft-hub connections can be serviced by hydraulic fit equipment also available at CJR.


To assure highest dimensional accuracy our propellers are moulded using patterns printed by 3D rapid prototyping printer - the most innovative way in pattern making. For higher volumes, aluminium or resin boxless systems are used.  Please click on the link to read more about pattern making.

Over recent years we have also invested in leading edge machining equipment and have developed our own CAD/CAM software and 3D modelling systems. Computer modelling allows for manufacturing to be simulated even before a pattern is made and a test casting produced, ensuring that manufacturing processes consistently deliver optimum results.  They are normally cast in nickel aluminium bronze from our highly accurate tooling. The propellers are either CNC machined or hand finished from the precise castings. They are then dynamically or statically balanced and MRI scanned to achieve up to Class S standards for optimum performance and smooth running.

Propellers can be manufactured with standard keyed hubs tapered to: ISO 1:10 , SAE 1:16, BS marine standard 1:12, as well as keyless hub tapered 1:30. Any other non-standard taper can also be machined.

Prop Boring & Fully Machined Props Cell

  • This Cell of machines has the capability to machine precision tapered bores as well as fully CNC machined blades surfaces for propellers through-out our range, as well as being capable of machining accurate custom propeller patterns in-house
  • This cell is also the home to our most expensive single CNC machine, which is a large capacity 5 axis Mill/Turn that can swing components up to Ø1,320mm (Ø52”), although typically works to Ø1,250 (Ø49”). Its “lights out” machining capability provides non-stop, 24 hours/day unmanned machining; so it carries on even when we have gone home for the evening!


Range of Custom Propellers


The Nautica propeller range is designed for relatively slow boats: fishing boats, trawlers, sailing yachts, motosailers, survey vessels, etc. – up to around 14 knots in speed, giving exceptional performance at low speed with increased trawling force.

MRK Revolution

Most commonly used type of custom made propellers for medium speed range (20-30kn) luxury yachts, displacement and planing vessels.

MRK Superprop

The MRK Superprop is a specific propeller option for high speed vessels (35kn+ sport boats, patrol crafts) and is custom designed range created to provide the ultimate in performance at sea. These propellers are individually tailored to a particular vessel's specification. The unique profiles are then optimised to deliver maximum speed, responsiveness and efficiency.

MRK Pilot

The MRK Pilot is designed specifically for work boats, in particular pilot boats. They are individually tailored to a specific boat, and designed to withstand the rugged environment that workboats encounter. The profiles are optimised for efficiency and speed, while ensuring cavitation erosion is minimised.

Aftersales Support

CJR is committed to providing propellers that outperform expectations. In order to analyse the performance of our propellers in the field, we have developed a sea trials system, TrialAPP that can be used on trials. We aim to constantly evolve and improve the design to increase efficiency and top speed as well as reducing noise and vibration, TrialDAS provides comprehensive data on the main sources of vibration and the overall yacht performance.

CJR also repair and replace existing designs of propellers. Standard CJR designs of propellers are still available for a vessel requiring a replacement.


Related Products

Shaft, prop nut, Shaft bracketStern tubeCouplingPropSmithHydraulic pusherHydraulic fit kit, TrialsAPP

  • 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