OIL & GAS INDUSTRY: Subsea Trencher and Cable Plough, Optical Tether & Connection Assemblies

  • Subsea Trencher and Cable Plough: Optical Tether & Connection Assembliescables connection assemblies connection assembly

    Subsea Trencher and Cable Plough, Optical Tether & Connection Assemblies

    Cables and flexible pipelines (eg. high density polyethylene (HDPE) pipelines or Coflexip-type) are usually much easier to trench than rigid pipelines. This is because they can often be deflected to the bottom of the trench within the trenching device. This means that problems with the trench infilling before the pipeline/cable touches down are eliminated and a suction device on the machine is not required thus reducing the trenching power requirements and the pull force.


    Trenching of telecommunication cables is usually accomplished by simultaneous ploughing and laying. The plough is pulled behind the cable lay barge and the cable catenary touches down just behind the plough. This method of trenching is very fast and is suitable for soft cohesive soils and sands with very flexible pipelines or small diameter cables.


    Simultaneous ploughing and laying is not feasible for hard clay soils, for cables/flexible pipelines greater than 50 mm OD or if there is an existing cable present nearby. This is because ploughs are not suitable in hard clays, as the diameter of the cable/pipeline increases the bending radius increases thus requiring a larger plough, and if there is an existing cable nearby the risk of damage is considered to be too high when using a plough.


    Optical Tether & Connection Assemblies

    Hydro Group designs and manufactures a range of optical cables suitable for use underwater and in harsh subsea environments. Our extensive knowledge of materials and underwater application engineering combine to give us the capability to manufacture high quality products.

    Applications Include:
    • Cables for videos • Data transmission • Communications • Power • Instrumentation
    • ROV • Cable plough • Trencher

    High grade materials are used in manufacture to produce cables with superior abrasion resistance, flexibility and reliability.
    • Polyurethane • EPR • Hytrel • TPR • Megalon • Polyethylene • Cross-linked

    The composition of our cables may vary widely:
    • Multi-conductor to give optimum usage for various video and camera type.
    • Twisted screened pairs, triples and quads with foil screening for communication and signal.
    • Insulation compounds suitable for high voltage and various power applications.
    • Sheathing compounds and braids for various mechanical and environmental requirements.

    The vast majority of our cables are customised to client’s specification; however we also keep in stock some of our most popular ranges in a variety of lengths.