A closer look at a DMC retrofit

For a family-owned business, a forward-thinking strategy is vital. After all, if you want to pass your business on to the next generation, you want to make sure that your assets are in the best condition possible. This is the working philosophy of Klaas Bakker, captain-owner of the Arcturus, a 22.5 metre-long pusher tug boat built in 1952 that he operates with his son Jacob.

Klaas bought the Arcturus in 2002 and since then has made a number of modifications aimed at increasing the longevity and efficiency of his ship. These have included strengthening the ship’s hull, installing new steering gear, and a Damen Marine Components nozzle in 2018.

Even though the DMC nozzle yielded an impressive 40% fuel savings, Klaas was interested in securing even more improvements: in terms of manoeuvrability, stability and fuel consumption. Sustainability was also a motivating factor, says Klaas: “We want to keep up with the times and go green. This means improving our overall efficiency.”

To this end, Klaas and Jacob came into contact with DMC for ideas about how to make their ship more efficient. Toofan Pour, Senior Sales Engineer at DMC, was the man with the answers. “This is quite an old ship, which means, when you’re looking at getting more efficiency, you cannot make any drastic modifications to the hull. You can only get efficiency gains by making modifications to the propulsion train: the propeller, nozzle or rudder. This is where DMC’s extensive experience comes into play –  we back up the advice we give our clients with the data from years of proven projects,” says Toofan.

“After talking to Klaas and Jacob and looking at the operational profile of the Arcturus – which called for a combination of manoeuvrability for small harbour work and fuel efficiency while sailing direct ‘A-to-B’ routes – the solution we recommended was to replace the existing single rudder with a double HD rudder system and hydraulic steering gear. Moreover, the new system is fully ES-TRIN compliant.”

The shipowner chooses the shipyard
The next step was to find a shipyard to carry out the retrofit. Klaas selected the Van Grevenstein shipyard in Krimpen aan de Lek, the Netherlands, a yard that he had previous experience with.

“DMC can work in any shipyard. The most important point is that our clients choose a shipyard they know and trust,” continues Toofan. “In this case, Van Grevenstein executed the structural scope of work, making some modifications to the rear working deck. And we oversaw the installation of the new rudder system, working on the changes to the hydraulic units and of course some new piping from the hydraulic unit to the steering machine, going from one to two cylinders. As with all our retrofit jobs, we kept a close eye on the costs, ensuring that all work was absolutely essential. So, for our work on the Arcturus, there was no need to make any changes to the electrical system or the control panels: these stayed the same.”

DMC assigned a dedicated project manager – Ton Verweij – to the Arcturus retrofit, acting as point of contact and ensuring optimum collaboration between Klaas and Jacob, the shipyard, and DMC. “Ton organised everything we needed: from the installation to the end result, answering all our questions along the way and visiting the yard regularly to monitor the work,” says Jacob. “The yard provided great service; they were quick and planned their activities very well.”

Was it worth it?
Several weeks after the retrofit of the Arcturus, it’s time to catch up with Klaas and Jacob to find out how their new DMC double rudder system is performing. In terms of fuel consumption, the father-son team have seen a marked improvement in efficiency. “Compared to before the retrofit, we are saving seven litres of fuel per hour while sailing one and a half kilometres an hour faster,” says Klaas.

And from a manoeuvrability perspective?
“These new rudders are simply amazing,” he answers. “We have had situations where we have been 96 metres long in a harbour that is 100 metres wide – we can easily turn around in that harbour! This is something I have never seen before in my 32 years of sailing.”

Achieving such a tight and accurate turning circle is due to the efficiency of DMC’s double rudder. Klaas explains: “With our old single rudder, even with the rudder to starboard, you could still see water coming out of the port side. With this double rudder, all of the water flows in the direction we want.”

Stability: empty ballast tanks?
Stability has also been improved, adds Jacob. “Working on the Wadden Sea, Westerschelde, or the Ijsselmeer, we usually have needed to add some ballast to stay stable in rougher conditions. However, since we have this double rudder, our ballast tanks are empty; the rudders actually work like stabilisers. We are more stable and we don’t feel any vibrations.”

As to the question of whether he would recommend a DMC double rudder retrofit to other tug owners, Klaas goes a step further. “If you are thinking about getting a DMC nozzle, my advice is to get a double rudder system at the same time. The nozzle saved us 40% fuel, and now we are saving even more with the double rudder. Looking at what we can do after this retrofit, it feels like we are sailing in a whole new ship.”

This brings us back to the subject of importance of family-owned businesses having a long-term strategy. “This retrofit is an investment for the future,” notes Jacob. “We have made the Arcturus ready for the next 40 or 50 years.”