Photos

Comments

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  David Slater February 24, 2021 at 10:24am

  Thanks for the info Gents. Very interesting.
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  Howard - Liverpool February 24, 2021 at 7:47am

  Thanks Jack & David - I think she is simply a mini dredger David. Cant dredge very deep tho so maybe dock entrances at low water???
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  Jack Dryden February 23, 2021 at 7:01pm

  

  Great photo Howard ,nice clean (red) dredger
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  David Slater February 23, 2021 at 10:45am

  Great photo. Any idea what it does. Bit of a contraption!
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    Jack Dryden > David Slater February 24, 2021 at 9:36am

    It is a water injection dredger as opposed to a suction hopper. Water injection dredging is one of a number of hydrodynamic dredging techniques, where the basic principle is to remobilise the sediments, using the action of natural currents. Water injection dredging uses water pumps connected to a series of nozzles on a horizontal jet bar. The nozzles inject large volumes of water at low pressure directly onto the sediment build up. This process fluidises the sediment build up, turning it into a density current which remains close to the water bed. The sediments are then picked up by this current and able to flow horizontally out of the channel or port. This process eliminates the need for traditional excavation dredging methods and the subsequent transportation of the dredged material. Nature takes care of the sediment transport, making water injection dredging a cost-effective dredging technique with less impact on the environment.
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    Howard - Liverpool > Jack Dryden February 24, 2021 at 9:47am

    

    Well done Jack - the horizontal nozzle bar can be clearly seen on this one. Cheers.
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    Jack Dryden > Howard - Liverpool February 24, 2021 at 9:49am

    I had a good video showing how this works which I linked to one of Colin’s photos but I can not find it .