CJR Propulsion extends its relationship with Mainprize Offshore

After successfully replacing the propellers on Mainprize Offshore’s MO1 support vessel, CJR Propulsion has extended its relationship with the Yorkshire-based vessel operator, securing the contract to develop a complete propulsion and sterngear package for its latest project, the MO5.

In 2018, CJR was tasked with addressing issues related to fuel efficiency and vibration for the existing MO1 vessel. At the time, the vessel was fitted with propellers that were causing excessive vibration under load and were not efficient – resulting in the engines burning too much fuel.

In response, CJR Propulsion designed a bespoke set of propellers, using its in-house Computational Fluid Dynamic (CFD) department to define the optimal set-up for this specific vessel’s hull form. Once the data was input into the software, the resulting simulations were tested, using over 20 million data points to understand the uneven flow of water around the propeller and sterngear. The setup’s pressure variations were also analysed to accurately predict and reduce cavitation and provide a realistic indication of the minimised noise and vibration levels Mainprize could expect.

After accepting CJR’s recommendations, the resulting propellers were manufactured within CJR’s Southampton manufacturing complex, certified to Class S, and installed on the vessel. On-the-water trials were then performed; the results showed a significant reduction in fuel burn for the same speed – equating to approximately 8–10% of annual usage.

The new MO5, which has just been launched, represents the latest in support vessel design, and is set to offer notable benefits for its operators, as Bob Mainprize explains:

“Following almost five years of research and development, many changes and fine tuning, extensive tanks testing, the highly anticipated MO5 will be launched in Europe in August. Fitted with the most up-to-date equipment and expected to outperform any of the current 26-metre vessels in terms of comfort, transit, and transfer height, we hope the vessel will become the new standard of offshore support vessels. Due to the proven quality and professionalism, they have already displayed, Walker Marine Design and CJR Propulsion worked very closely to ensure the propulsion and stern gear system was developed to operate at maximum efficiency in many operating conditions, and we have total confidence it will again exceed our expectations.”