Unexpected crane movement slows vessel construction

Crane builder Liebherr and offshore wind vessel operator Seaway 7 experienced a setback in the construction of monopile-installation vessel (heavy load carrier) Alfa Lift (IMO 9889980) after an “unplanned movement” of a key crane component on the ship necessitated a technical investigation.

Alfa Lift was ordered by offshore wind specialists OHT in 2018. OHT merged with Subsea 7’s renewables unit this July.

The vessel is currently being built in China at China Merchants Heavy Industry (CMHI) shipyard in Jiangsu.

Alfa Lift is a semisubmersible heavy lift crane ship that is being purpose-built for the installation of offshore wind tower foundations and transition pieces. It is equipped with a novel crane designed and built by German heavy lift manufacturer Liebherr.

The unique crane is designed to hoist the heaviest offshore wind foundations, up to 3,000 tonnes, that are expected to come online in coming years. Its design features a foldable A-frame, which can be lowered to reduce the vessel’s air draft when needed.

The A-frame unit for the HLC 150000 shipped from Liebherr’s Rostock plant to China Merchants Heavy Industry’s Jiangsu shipyard in March, shortly after the Alfa Lift’s hull was launched. Liebherr said that its own technicians would be conducting the installation and commissioning.

Gregor Levold, marine sales director at Liebherr Rostock, said that the crane could only be assembled and installed once the vessel had reached a specific phase in its construction. This meant that the manufacturing timelines were “finely balanced”.

Levold added that, “due to the extensive experience of our experts, a team of Liebherr specialists will travel to China and support with supervision for the installation, commissioning and testing process (ICT) of the HLC 150000 at the shipyard.”

However, on Monday this week, October 18th, Seaway 7 said it had been informed of an incident involving the folding A-frame on the HLC 150000 crane aboard the Alfa Lift. The company described it as an “unplanned movement,” and said that no personnel were injured. The cause of the incident is under investigation.

At the moment, all that Seaway 7 would say was that “the incident is a matter between the shipyard and crane vendor, and it is too early to indicate if this will have an impact on delivery schedule of the vessel”.

Alfa Lift has been chartered to install all of the monopile foundations for the UK’s Dogger Bank offshore wind farm, the largest project of its kind in the world. The construction timeline calls for Alfa Lift to be on site and working during 2022, with the first power from 2023.

This “unplanned movement” will be the second incident involving a Liebherr crane aboard a new offshore wind vessel in two years. In May 2020 the heavy crane aboard offshore installation vessel Orion 1 suffered a hook failure during load testing, resulting in a whiplash and boom collapse. The Orion 1 was in the port of Rostock after having its 5000-tonne heavy-lift Liebherr crane installed. During the test load of the crane (35 metres outreach and 175 metres hoisting height), the hook collapsed with the result that the crane collapsed.

2021-built, Norway-flagged, 65,692 gt Alfa Lift is owned and managed by Offshore Heavy Transport AS.