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    Trials of subsea dredger exceed expectations

    Vessel & ROV News // April 9, 2015

    Trials of a new subsea dredging system, which can move one tonne of rocks on the seabed per minute, have exceeded all expectations in terms of efficiency and performance.
    The Predator Subsea Dredger underwent a number of trials while fitted to the Triton XL26 work class ROV used for training and trials at The Underwater Centre’s Loch Linnhe site in Fort William.
    Nine tonnes of 50-60mm rocks were placed on areas of the seabed to recreate a range of terrains typical of the offshore subsea environment to be dredged during the trial, and the task was completed in between eight and nine minutes.
    Further trials designed to test the integrity of the system, including the dredging of 100-130mm rocks in an attempt to break the machine and to identify any weak spots, highlighted the robustness and strength of the product.
    A final test of the agitator system, which shoots out jets of water at the suction head end directly onto the seabed, breaking up the peat at the bottom of Loch Linnhe and dredging it at the same time, worked exceptionally well and did not affect the performance of the dredger. It can also be reconfigured subsea, with the use of a second work class ROV or diver. 
    The Predator Subsea Dredger was designed by Subsea Tooling Services (STS), based in Oldmeldrum, Aberdeenshire, which offers a diverse range of subsea equipment.
    STS Business Development Manager Billy Milne said the main objective was to prove that it was as efficient, if not more so, than other dredgers currently on the market.
    “We wanted to prove the dredger’s capabilities to our clients, as well confirm our development tests by filming it in action in conditions close to those it will be used in offshore,” he said.
    “The Underwater Centre is the only facility within the UK that could have undertaken the task of testing and filming the Predator Dredger. The highly skilled ROV team demonstrated their ability to handle such an operation. From planning the scope of work to operating the ROV with the Predator Dredger and subsequently delivering footage of the trial, The Underwater Centre has provided a service that is invaluable to our company.”



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