---

MAN Diesel & Turbo has been working in close cooperation with its client, Norway's Odfjell, on a project to help the ship operator upgrade its propulsion system and achieve fuel savings.

According to data independently verified by the Norwegian Marine Technology Research Institute (Marintek), the company's vessels have been able to reduce fuel consumption by more than 20 percent.

In a video posted by MAN Diesel & Turbo on 26th August, Jens Ring Nielsen, Senior Manager, MAN Diesel & Turbo, Propeller & Aft Ship, explains that two key changes were made: the first was to change the existing conventional propeller blade with MAN's Kappel propeller design; the second was to add an extension to the propeller hub and a rudder bulb, which is an extension to the rudder.

"So that means now you have a streamlined flow from the propeller towards the rudder, and that gave a further improvement in the efficiency," Nielsen said.

After the first vessel was upgraded in August 2015, Odfjell carried out a sea trial where the results before and after the upgrade were compared.

Helge Olsen, Senior Vice President, Ship Management at Odfjell, explained: "Clearly we were very satisfied and the sea trial concluded with an actual result of a 20 percent improvement, 5 percent better than our expectation. So, we have continued to monitor the ship, because that ship has not been in operation for a number of months, and it was still confirmed to be in the upper 20 percent - more than 20 percent.

The results were verified by Marintek. In order to carry out the test, Marintek's Dr Kourosh Kousan explained that a scale model was tested and the original rudder was also tested at the facility's towing tank. This enabled the researchers to accurately calculate the fuel consumption for a full-scale vessel. Then, an alternative rudder was used under the same testing conditions and the results were compared.

"By comparing the results of the original with the new configuration, then we can quantify what is the real gain from the new solution. But in the best case, comparing to the original configuration, we had more than 20 percent saving [sic], so that's quite a lot. The usual projects we are doing is maybe around 10 percent saving [sic]," Kousan said.

Explaining the reason for carrying out the upgrades, Nielsen said: "The benefits for us as a company are basically the following: one it gives us a higher environmental rating, which is normally issued by Rightship. So if you have a higher environmental rating, you are accepted by all customers and you are also a preferred choice by investors. If we have a low environmental rating, you may actually be out of business for some customers and be less attractive for investors.

"This project also gives us, of course, a saving which results in lower spending of fuel, we reduce our costs and it makes us more cost competitive."

Nielsen said Odfjell had decided to work with MAN "because they offer the best total solution - a solution that includes all the various components involved in this upgrade, because it involves more than the propeller systems. It involves the upgrade of some part of the engine equipment, the rudder and some other parts of the ship's equipment. So MAN company could offer the best total solution for the upgrade".

Describing the company's strategy when it comes to upgrading the ships of its clients, Kjartan Ross, Business Development Manager, Man Diesel & Turbo, Propeller & Aft Ship, remarked: "We believe that the holistic approach is the way forward. It's a way of having existing vessels upgraded to such an extent that they can actually compete with the newest vessels in the market, and the newest designs."

Image: The Blow Flora was upgraded as part of the project in Doha, Qatar.