Sub-Atlantic Limited to deliver 6,000m ROV to Subsea ResourcesVessel & ROV News // August 23, 2005
Remotely Operated Vehicle (ROV) manufacturer Sub-Atlantic Ltd, based in Aberdeen in the UK, has been awarded a contract to deliver a 6,000m depth rated version of its light Workclass Comanche ROV to salvage company Subsea Resources Plc.
Subsea Resources recently acquired a 75m survey and salvage vessel, from which the Comanche will be operated. The Comanche was chosen as the most suitable vehicle for the varied tasks that will be required during both the survey and recovery operations planned in water depths down to 6,000m.
Equipped with both a 7- and 4- Function Orion Manipulator from Alliance partner Schilling Robotics, the Comanche will be able to undertake tasks that previously were unthinkable from a vehicle of this size.
Sub-Atlantic and Schilling Robotics recently formed the Schilling Sub-Atlantic Alliance to provide customers with the technical solutions possible from a single source.
The ROV was designed to address the increasing demand for more capable electric ROVs to undertake tasks traditionally carried out by hydraulic ROVs. The company claims that the lower cost of ownership and increased reliability of electric ROVs makes Comanche a viable alternative for offshore operations requiring higher levels of intervention
Designed using a 3000 volt/400Hz power transmission system, which is also used on the smaller Sub-Atlantic inspection class Mohican ROV, Comanche is equally suitable for free swimming or Tether Management System (TMS) operations.
“Thruster technology is of critical importance on electric ROVs and the SPE250 brushless DC thrusters utilise our unique StatorShieldTM technology. StatorShieldTM technology creates a physical barrier between the rotor and stator, preventing water contamination to the electrical parts, a common failure mode with existing electric thrusters,” said Colin Millum, Joint Managing Director of Sub-Atlantic.
The standard Comanche is rated to 2,000m with a payload of 150kg, however Subsea Resources had needs that exceed this standard.
Increasing the operating depth on the Subsea Resources Comanche to 6,000m and also raising the payload capability to 200kg were key to meeting the challenges likely to be experienced during salvage operations. The result is an ROV which can be operates at these extreme depths, while carrying an extensive array of high quality survey sensors as utilised by Subsea Resources.
John Kingsford, operations director of Subsea Resources stated “It was critical that Subsea Resources find a technical solution for working on salvage at the variety of depths where we have identified key targets. The ability of Comanche to operate the Tritech Super ZipJet and work-class manipulators proved to us that this ROV will be truly capable of performing intervention tasks on the salvage projects we have scheduled in the near future”.