Cable Innovator - Cable Layer

At 10,040dwt, the Cable Innovator is the world's largest vessel of its kind, specifically designed for laying fibre optic cable. The vessel was built by Kvaerner Masa of Finland. All cable-laying operations are carried out over the stern, so the ship travels much faster to the site and is not slowed down by conventional bow sheaves. It can operate in extreme weather while providing optimum protection for all cable-handling operations. It is equipped to deploy a remotely operated vehicle (ROV).

DESIGN

The Cable Innovator cable handling equipment centres on a 21-wheel pair linear cable engine (LCE) and a 4m diameter electrically driven cable drum with fixed-angle fleeting rings and fleeting knives that are primarily responsible for controlling the cable lay. The cable drum has 4,874m³ maximum cable volume and 8,500t maximum load.

The equipment also comprises a four-pair DO/HB unit with an hydraulically activated traversing cable deflector and a two-deck head-mounted single-wheel pair of cable transporters, capable of traversing onto either cable line. The Cable Innovator has a conventional set of cable working instrumentation and two computerised (dual redundant) cable instrumentation systems.

There is a 35t SWL (sea state 5) A-frame with working arc from 45° outboard to 45° inboard to handle the plough used to bury the cable in the seabed. There are two 10t SWL buoy/stores cranes aft, one 5t SWL stores crane forward and one 2t SWL stores crane forward.

PROPULSION

The vessel's power comes from five Wärtsilä Vasa diesel engines, three 9R32E units of 3,645kW each driving a 4,160kVA/60Hz l3.3kV ABB AC generator, and two 6R22/ 26 machines of 975kW (1,150kVA at 13.3kV), which provides a total installed power of 12.8MW.

A total of 5.3MW of power is available at the vessel's single main KaMeWa fixed pitch propeller, which is powered by two ABB variable speed, reversing AC electric propulsion motors, each rated at 2,700kW. The vessel has no rudder but there are two 12t KaMeWa tunnel thrusters located at the stern, each rated at 900kW and able to provide about 24t of transverse thrust. A White Gill jet thruster of 2,000kW and a tunnel thruster of 1,200kW are installed at the bow.

AUTOMATION AND CONTROL

The Cegelec 902 duplex system allows the vessel to be controlled in various modes from a manual joystick mode to a DP mode where the position and heading are automatically controlled. In addition, the system offers transit modes, the vessel being controlled either to maintain a set heading or to follow a specific track.

The GEM80/400 and SPARC computer located in the master DPS console provide the control and interfacing to the thrusters, main propulsion motors, position measurement and navigational systems, power systems, plough, event monitoring and remote joystick stations. A further GEMS0/400 independent joystick system also provides interfaces to the thrusters and the steerable nozzle and gyrocompass.

A full suite of duplicated modern navigational, shallow and deep water bathymetry recording and radio equipment are installed and upgraded to ensure a state-of-the-art performance, including multiple GPS and SATCOM facilities. The Position Measuring Equipment (PME) features a hydro-acoustic system with super shore baseline, DGPS and two taut wires. These supplement the gyrocompass, vertical reference unit, anemometer and Artemis systems. Pooling the data together from all of these elements secures the most accurate position fix.

The system can also display and take account of plough tow cable tension when the vessel is engaged in cable laying, initiating an alarm if the cable tension rises too high or automatically slowing the vessel's speed.