New OOS SSCVs undergoing final touches

The two offshore mast cranes on board OOS International’s semi-submersible crane vessel (SSCV) OSS Walcheren have been installed and load-tested, while the company’s SSCV OOS Serooskerke is now being prepared for sea trials.

OOS International ordered the construction of two vessels from China Merchants Heavy Industry (CMHI) in August 2016, announcing they would be used for offshore wind installation and decommissioning, among other things.

The vessels feature two heavy lift Huisman cranes with a combined lift capacity of 4,400t with subsea lifting and active compensation capability, and an enhanced dynamic positioning class 3 system (DP3) from Kongsberg.

“Over the last few months, construction and commissioning activities on OOS Walcheren has made huge progress despite the challenges posed by the global pandemic”, OOS International said on social media.

The cranes were load-tested up to 2,420 tonnes, each using a barge load.

“Moving forward, the vessel will be busy with outfitting her offshore mast cranes with the super fly jib in August 2020, as well as working on her interior accommodation, marine and electrical systems”, OOS International said.

OOS Serooskerke is currently being prepared for sea trials, with marine and electrical systems being tested daily to identify any faults and verify functionality to minimize unexpected failures while at sea, according to the company.

Several final tests and installation will be done during the vessel’s sea trial eriod, including thrusters installation, as well as final verification for ballast systems, navigation systems, crane active compensation, electrical short circuit tests and Integrated Software Management System (ISQM).

CMHI started building the semi-submersible crane vessel on 24 May 2018 at its Jiangsu yard, with the delivery period then set to first quarter of this year. OOS Serooskerke was scheduled for delivery in mid-2019.