Super crane for mighty jack-up legs

The turn-around in the energy sector, along with the exploitation of wind at sea and the building of specialised installation ships for offshore wind farms have stimulated old and well-proven skills at Lloyd Werft Bremerhaven. More than ever before, the yard is now developing into a centre for specialised shipbuilding of high quality. In the wake of the fitting-out of two RWE/Innogy installation vessels "Victoria Mathias" and "Friedrich Ernestine" nearly two years ago, Lloyd Werft engineers and craftsmen have been able to further expand their skills in specialised shipbuilding. Those skills in particular will now be very much in demand for the completion of the 14,800 GRT "Aeolus", which belongs to the Dutch shipping company Van Oord. Lloyd Werft has until July to get that mighty newbuilding ready for sea.

Since the beginning of January and at the request of Van Oord, Lloyd Werft craftsmen have helped Sietas to complete the building of "Aeolus". However the newbuilding has now had to be brought to Bremerhaven for fitting out and for the complicated lifting into position of her four platform legs. "We were also able to win this very interesting job because we have already demonstrated with "Victoria Mathias" and "Friedrich Ernestine" just what we are capable of", explains Lloyd Werft Chairman Rüdiger Pallentin. He means, in particular, the skills to handle complicated hydraulic machinery of unusual dimensions and the extensive and difficult requirements for positioning the four legs on the "Aeolus".

The four 87 metre long steel legs, each weighing 920 tons, will be settled into their jacking positions on the 139 metre long and 38 metre wide ship using the world’s biggest crawler crane. Thorsten Beiler (49) Lloyd Werft’s technical director, says this is one of the very special demands of the job, but one which the yard has already tackled successfully with the RWE installation ships: "We have made a good start in the new offshore market, which is an exciting one and very challenging for us", he says. When the "Aeolus" arrived at the yard’s outfitting quay, a ship of similar dimensions – "Bold Tern" belonging to Fred Olsen Windcarriers – was berthed alongside it for conversion work before going into service in a new operational sector. Lloyd Werft has also already shown what it is capable of with Hochtief’s "Innovation".

Van Oord is in turn now also demonstrating its trust in Lloyd Werft’s experience as well as in its flexibility and deadline reliability. The Rotterdam-based Dutch have been specialists in international hydraulic engineering since 1868. Their shipping company deploys more than 100 ships, most of them dredging vessels and suction dredgers: some of them, for example, were used to build Dubai’s artificial islands. However the installation of wind turbines at sea is new territory, even for the Dutch and with the installation vessel "Aeolus", they will get the most advanced special ship ever to operate at sea-based wind farms.

For Thorsten Beiler however "Aeolus" is an extra-special challenge. Over the next few days a Type LR 13000 crawler crane with a 3,800 load capacity and a 130 metre long jib will arrive directly from the Netherlands to tackle the main part of the job. And it will put all other heavy moving machinery into the shade. "It will take about four weeks just to set up the crane and have it ready for operation by mid April", says Beiler. It will then take a good fortnight for all four hydraulic jack-up legs to be installed.

Plenty of other work will be taking place parallel to this.

After the legs have been installed, spud cans have to be mounted. These are the giant "elephant feet" at the bottom of each leg on which "Aeolus" will be able to secure itself on the sea-bed, even on difficult terrain. To ensure that the legs meet requirements, reinforcing modifications to the hydraulics and cylinders are also needed.

The yard is also involved in installing the vessels own on-board crane, capable of lifting up to 900 tons. In addition, it is building and fitting the deck reinforcements and foundations for a second 500 ton capacity auxiliary crane and also for a third on-board crane, which is designed to help improve flexible working at sea. Also being built are reinforcements and foundations for a folding pile gripper, with which heavy building components can be positioned. On the hull of the ship, Lloyd Werft is mounting a special access system which will allow smaller ships and tender boats to dock.

As with other vessels of this type, the yard is also fitting quite a few foundations and fastenings for heavy turbine and other wind farm components. Every such ship also needs a gangway system leading from the vessel to the wind farm structure and this is also being installed on board the "Aeolus".

A delighted Thorsten Beiler says of the exciting challenges being faced on the "Aeolus": "the job really suits us"!