Jumbo plunges into the deep
The difficult working conditions when laying underwater pipelines make such an enterprise one of the most interesting project cargo undertakings. Jumbo, a Dutch heavylift and offshore specialist, is participating in the laying of a new connection in the Eastern Mediterranean. An integrated deep-water winch system and a specialised heavylift ship are two exceptional aspects of the project.
Jumbo, a Dutch heavylift consignments specialist, is once more set to prove its skills from the end of this year when it is set to become involved in a project to install a new pipeline between Anamur (Turkey) and Kyrenia / Girne (Turkish Republic of Northern Cyprus). The contract was awarded by the Malaysian pipe-laying contractor Sigur Ros.
Under the contract Jumbo will deploy its Fairplayer heavylift vessel to transport and install 126 gravity anchor spreads in water depths of up to 1,400 m. All project management and engineering tasks will be carried out by Jumbo.
The company will collect the materials needed from the Turkish port of Mersin Tasucu Seka, where they will be loaded on board the Fairplayer using the vessel’s own 900 t mast cranes, ready for transportation to the offshore location and for installation. The Fairplayer has a carrying capacity of 12,625 dwat and it’s on-board cranes can lift 1,800 t in tandem operations.
The Fairplayer will sail south from Mersin, and will then install the 230 t gravity anchor, tether wire and sub-sea buoys, to be used to moor a pipeline with a 1.6 m diameter running 80 km from Turkey to Northern Cyprus. The pipeline will be suspended in spans of approximately 500 m, floating at a depth of approximately 250 m.
The tether ropes, which are 116 mm in diameter, will be cut to varying lengths to match the corresponding water depths along the pipeline’s route. Towards the tops of the tether wires the sub-sea buoys, 8 m long and 3 m in diameter and weighing approximately 17 t each, will be positioned to moor the pipeline. The anchor spreads will be lowered into position using both of the Fairplayer’s mast cranes. One of the cranes will oversee the deployment of the buoy and tensioning of the tether wire, whilst the other will lower the anchor.
One of the specialities of this delicate and intricate operation is the fact that both of the cranes involved are equipped with an integrated deep-water winch system, which will allow the equipment to be installed without the need for a so-called wet handshake – that is to say the submarine transfer between two hooks. 14 km of crane wire will be applied to the winch, which can carry out installations in water depths of up to 3,000 m. To successfully carry out the installation work it is additionally very important that the Fairplayer maintains its exact position whilst it is executing its work. To this end the Fairplayer’s on-board class 2 dynamic positioning system comes into play to ensure the required results.