Besides typical cargo and passenger ships, Remontowa Shiprepair Yard SA in Gdańsk also repairs special ships of various kinds, including the ones used in port and offshore construction and sea engineering. However rock dumping and fall pipe vessels are not very frequent visitors to the yard, perhaps as the world’s fleet of such kind of highly specialised vessels is not numerous either.
The Tideway Rollingstone is one of such complex vessels belonging to Belgian DEME (Dredging, Environmental & Marine Engineering) specializing in dredging, port construction and offshore engineering works. Former Super Servant 1 (until 1994) was built as a semi-submersible heavy-lift ship, at Japanese yard Oshima Shipbuilding Co., Ltd. in 1979. In 2012 she was converted to a fall pipe vessel, which features deadweight of 14 310 t, 140 m overall length, 32 m beam, 4.8 up to 6.8 m draught and cruising speed up to 12 knots.
Currently, the ABS classed vessel flies the Dutch flag, with Flushing as its home port. Recently the ship has been busy in Russian ports of Baltiysk and Kaliningrad.
This kind of ship is often described as a pipe burying vessel, a fall pipe vessel or either a rock or a stone dumping vessel. It works at installation of offshore wind farms foundations, preparing the seabed for pipe laying. Among its tasks there is also stabilising subsea pipes and burying cables on the seabed, by precise dumping of aggregates, gravel or rock onto predefined subsea locations.
A fall pipe vessel, such as the Tideway Rollingstone, features a moon-pool, amidships, through which a fall pipe is slid out, transferring the dumped rock precisely to cover various pipeline or cable connections or other subsea installations.
This is not the first ship of this kind to be serviced at Remontowa SA. In 2004 and 2013 the yard repaired the Seahorse fall pipe vessel. The Tideway Rollingstone has also previously been at Remontowa SA – various works were carried out, while the ship was docked in November 2011.
This time, the vessel visited the Remontowa SA yard in November. The main task was to install the compacting machine. However, as the works progressed, the owner was ordering further tasks, such as modifications of feeding hoppers, repairs to cargo hold hatch coamings or installation of additional cabling.