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Not all propellers are made equal
Propeller packages from CJR consistently outperform the competition and are proven to increase top speed, consume less fuel, last longer, and reduce noise, vibration and cavitation.
Every CJR propeller is designed to the highest quality standards and is custom-made for the specific vessel in question using advanced design and production technology to do so. Our continuous investment in precision manufacturing technology is combined with a data and intelligence-led mindset, to deliver the ultimate in propulsion performance and efficiency as standard. Equally, every CJR propeller can be manufactured to any classification society rules, including all IACS societies for complete peace of mind.
The CJR propeller manufacturing process
Our unique end-to-end is unrivalled in Europe and leverages the latest in CFD and FEA design software, highly accurate pattern-less moulding, and five-axis CNC-machining to create truly bespoke propulsion solutions that deliver long-term benefits and efficiencies. This means every CJR propeller is designed without constraint, to the precise requirements of the vessel and its intended application.
Design
If required we can analyse the entire propulsion system of each boat starting from hull resistance prediction and hull propulsive factors. We select the most efficient gear ratio, recommend changes if needed and analyse flow in every point under the hull using the most advanced CFD tools developed specifically for our requirements.
Robot Machining of Sand Blocks
For all propellers made outside of a production run, we will miss out the pattern-making process and use this method for casting propellers instead. We machine blocks of sand and resin to make a mould for casting propellers. This is a very quick process which allows us to make propellers in two weeks when required.
Pattern Making
We use patterns if we are making a series of propellers. For isolated, bespoke orders we wil use the sand moulds instead (see above). Precise patterns ensure high accuracy of final product and are one of the most important stages in the manufacturing process of casting items of complex geometry like propellers, rudders and P-Brackets.
Casting
Casting is the stage at which the moulds are filled with molten metal. CJR’s foundry team has the combined benefits of over 150 years experience in the industry. This experience coupled with our excellent software, tooling and patterns provides an extremely efficient and highly productive output of quality castings.
Machining
CAD/CAM controlled machining of the cast propellers, P brackets and rudders are undertaken to the fine tolerances of their original design, which ensures that the finished components perform as predicted.
Finishing
Our processes ensure that the geometry of our finished castings is always true and accurate to the original design. Consequently, there’s little need for extensive finishing, which can offer significant cost and time savings. Additionally, our digital inspection equipment thoroughly checks every component for everything from geometry to skew, rake and pitch.
Quality checks
CJR is committed to achieving a best in class standard of quality with all products and processes. The final product that is supplied to our customers has passed a full process of quality procedures involving material traceability and analysis and dimensional evaluation at each phase of manufacture. All propellers are inspected to ISO 484 Class S standards to ensure optimum performance, smoothness and efficiency
Propelling results
Propeller packages from CJR consistently outperform the competition and are proven to increase top speed, consume less fuel, last longer, and reduce noise, vibration and cavitation.
Customers have reported saving as much as 10% in fuel costs per annum and have increased top speed by up to two knots simply by switching from a set of hand-finished propellers to a set of fully bespoke CJR fully CNC machined propellers.
The importance of having the right propeller
The propeller is one of the most sensitive parts of the boat and is impacted by the vessel’s displacement, trim, appendages, hull fouling and engine performance, as well as trial conditions like sea state or wind. Whether your propellers are intended for a superyacht, motor yacht or commercial vessel, you need a propulsion partner that takes the time to understand every relevant factor; how your vessel is being used, its loading and any individual propulsion requirements or challenges.
We gather this critical vessel data and use our technology-driven approach, commitment to customer service and manufacturing excellence to provide our customers with the confidence they need – safe in the knowledge that their propeller package will meet their requirements in terms of performance, efficiency, longevity and ride comfort.
Rapid Design and Manufacturing
CJR has recently launched a rapid turnaround service offering bespoke, fully optimised Class-S propellers in just 14 days or less. Designed for propellers up to 1500mm in diameter, our replacement propeller services can save as much as three months from the typical replacement timeline. For more information,
Our custom propeller range:
NAUTICA
Our Nautica propeller range is designed for vessels looking for exceptional performance at lower speeds, making it ideally suited for fishing boats, trawlers, sailing yachts, displacement motor yachts or survey vessels.
MRK REVOLUTION
Our MRK Revolution propeller range is our most popular custom-made solution, designed for vessels looking for minimal noise and vibration at a medium speed range of 20-30 knots). It is particularly popular with large luxury yachts, semi-displacement and planing production motorboat builders.
Billfish Propeller
Our Billfish propeller range is designed specifically for high speed Sportfish boats and has proven to outperform competitors at speeds of up to 45kts. The design and manufacture of the Billfish propeller takes into account the specific operating requirements of the Sportfish market, including maximum speed but also the ability for operators to ‘backdown’ on fish. We have even had reports that the CJR Billfish acts to ‘bring up the fish’.
MRK SUPERPROP
The MRK Superprop range has been developed specifically for high speed vessels (sport boats of 32 knots plus, production yachts and patrol craft) and provides the ultimate in performance at sea. After the propellers are tailored to the 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 workboats, in particular, pilot boats. These propellers are designed to withstand the rugged environment that workboats encounter. The propeller profiles are optimised for efficiency and speed while ensuring cavitation erosion is controlled.
