In September, the project to retrofit the multi-purpose offshore vessel Grane R owned by Rohde-Nielsen A/S was completed at the Remontowa shipyard.
Grane R is a powerful offshore grab dredger and stone placing vessel capable of performing a variety of projects related to trench dredging and backfilling, boulder removal, rock installation and other offshore activities.
The most important task was to retrofit the ship with sponsons – the projections (buoyancy casings) from each side of the hull, used to enhance its stability. It is worth recalling that since the end of the 1990s Remontowa has modernised several dozen ships in this way, but mainly Ro-Pax ferries. Installation of sponsons on ships such as the Grane R is rare. The implementation of this project involved additional modification of virtually all ship’s systems.
The challenge was limited time for logistics and execution of works, but the retrofit project was completed as scheduled and according to the shipowner’s expectations. Prefabrication of the sponsons began even prior to the ship’s arrival in Gdansk. Grane R is a powerful offshore grab dredger and stone placing vessel capable of performing a variety of projects related to trench dredging and backfilling, boulder removal, rock installation and other offshore activities.
The most important task was to retrofit the ship with sponsons – the projections (buoyancy casings) from each side of the hull, used to enhance its stability. It is worth recalling that since the end of the 1990s Remontowa has modernized room, construction of a new sea chest for the BWT system, installation of a new sonar structure, modification of the sprinkler system, construction of a new technical room in the bow section of the hold, installation of a foundation on board for a new backhoe loader as well as prefabrication and installation of a foundation for the chute to be used for dumping aggregate. The azimuth thruster was inspected and overhauled under the surveillance of the service technician, and the boat landing ladder was mounted on the starboard side. Moreover, the hull with sponsons underwent maintenance and was painted, as well as all new constructions made by the shipyard.
On the Grane R, the shipyard installed two sponsons, each 1.6 m wide, containing six tanks on each side. The total weight of the entire assembled structure has reached 203 tonnes. Six new tanks were partially connected to the old ballast tanks, while the two anti- heeling tanks – one on each side – were supplied with a new pipeline of the ballast system. All the new tanks have been fitted with probes and the connections to the measuring system have been prepared. Tank venting has been modified and the outboard outlets of the waste system and engine room systems from the bow section have been extended. The works in the hold included completing the rinsing system, assembling the brackets and making the gratings leading to the sewage ducts. Other works include the installation of new rails on the starboard side, modification of the fuel system in the engine
Source: Remontowa