The reason for retrofitting

MT Marilee is a part of Swedish-based Marinvest’s fleet. Originally, the product tanker was built without a vibration compensator. However, after a period, it was not possible to operate at lower rpm (slow steaming) due to vessel problems. These problems are often seen with vibrations and include, but are not limited to, cracking in various machinery support and vessel structures during incredibly slow steaming. Given these issues, it was chosen to install a G&O vibration compensator.

Excessive Vibrations

This was a necessary precaution as the vibrations are harmful towards machinery and vessel structure. In addition to this, the vessel’s incapability to operate according to the original design load resulted in an increase in the average fuel consumption. Fuel savings are a bonus according to Mr. Srecko Harej, Senior Technical Superintendent at Marinvest: “after the installation of the vibration compensator, all vibrations were fully eliminated, regardless of which rpm the main engine was running at, which is also confirmed by the crew onboard.”

The elimination of vibrations Mr Harej recorded could also lead to reduced wear. This would have a potential knock-on effect of lowering overall maintenance costs for the vessel. When the compensator was installed and operational, the average fuel consumption decreased approximately 0.8 tons per day because the vessel was able to increase the CPP pitch – which was not possible before. Furthermore, the vessel was able to operate within the original design load leading to a propulsion efficiency improvement of a staggering 5%.

Lastly, it is noteworthy that MT Mariann, MT Maribel, MT Mari Ugland, MT Marika and the MT Marinor had similar retrofit.