Aeolus

Van Oord's Offshore Wind Installation Vessel Aeolus underwent a crane upgrade and spudcan modification to remain competitive in the offshore renewable energy market. The ship positions itself by lowering its legs into the seabed and raising itself up. In the dock it stood with its legs raised to be handled.

After a previous conversion in the winter of 2020-21, the Aeolus will return to Damen Verolme. It was there from December 6 to February 28 in the large dock. Much work had already been prepared before the ship arrived. “The collaboration with client Van Oord and crane supplier Huisman went very well,” says Senior project manager Edwin Steijaert.

Tree rest

The Aeolus is a heavy lift vessel. The vessel already received a crane upgrade during a previous conversion at our yard. Then a 1600 ton crane was installed on the ship. The windmills at sea are getting bigger and bigger. After the work at Damen Verolme Rotterdam, it can also lift the latest generation of wind turbines,” says Edwin. “The crane mast has been extended by 40 meters for this purpose. Which now sticks out ahead of the bow because of this. The crane's longer mast has a boom rest built on top of the bow, which is attached to the accommodation on the bow. Before the Aeolus arrived in December, we had already started the construction of the new tree rest. It was tailed with a sheer leg and installed directly on board.”

Higher quality steel

The bow section has also been reinforced in order to have sufficient load-bearing capacity: the legs of the boom rest are now on the bow. It is equipped with high-quality and thicker steel. Due to the changed position of the crane, the helicopter deck also had to be relocated. The platform is now on the center line in front of the ship's bow. In the end, we managed to complete the entire conversion in three months.

Dock glands

The new docking points, which were installed by Damen Marine Components last fall, came in handy when positioning Aeolus in the dock. In the dock, which is 400 meters long and over 90 meters wide, even the Aeolus (140 meters long and 45 meters wide) appears to be a relatively

“small boat”. The ship was positioned very precisely by the docking glands: it had to be placed very accurately on the port side at 3 meters from the dock wall. The legs have remained raised in the dock. Aeolus stood on a 4.8 m high dock bed.

Spudcans are inverted cones located at the bottom of the legs that provide the load-bearing capacity and stability of the ship when raised. These could be prepared again for work on a sandy seabed. A previous job for Aeolus was on rocky ground, for which the spudcans were equipped with long steel damped pins. These now had to be removed for work on a sandy seabed.

Constricted

“While we were installing the boom rest and the spudcans, Huisman people were working on the crane,” says Edwin. “They shaved out all the cables and then re-tied them into the new extended crane mast. When the boom rest was fitted, we were able to check whether it supports the mast in the correct position. Fortunately, that turned out well.”

On to the next job

The Aeolus sailed to Vlissingen for the last work to depart from there for the French Brittany. There she will be used for the construction of the offshore wind farm in the bay of Saint Brieuc.