Bespoke high-voltage, electro-optical and electro-hydraulic connections for cable burial, pipeline intervention, seabed excavation and tracked subsea machinery.
Cable systems engineered around the complete subsea spread
A trencher, plough or crawler is only as dependable as the connection that supplies and controls it. Depending on the equipment architecture, that connection may power propulsion, pumps, cutters and auxiliary equipment; carry commands, telemetry, video and sensor data; provide hydraulic services; and withstand the mechanical loads created during launch, operation and recovery.
Fibron designs and manufactures bespoke subsea cables and umbilicals for mobile seabed equipment. Rather than adapting a standard product, our engineers develop the electrical, optical, hydraulic and mechanical architecture around the machine, its deck spread, handling system and intended operating cycle.
Different machines create different umbilical duties
Subsea trencher umbilicals
Jet trenchers, mechanical trenchers and tracked burial vehicles can demand substantial electrical power together with dependable control and high-bandwidth communications. A trencher umbilical may combine high-voltage power cores, earth and auxiliary conductors, screened control elements and fibre optics within a heavily protected construction.
Where the umbilical also supports suspended or deployment loads, steel-wire armour or another engineered strength system can form part of the load path. The design must then account for minimum breaking load, working tension, torque balance, bend-over-sheave fatigue and load transfer into the end terminations. Current rating should also be assessed for both deployed operation and storage on a multilayer winch.
Subsea plough cables and umbilicals
A towed cable or pipeline plough presents a different engineering problem. The primary towing force may be carried by a dedicated tow wire or combined handling arrangement, while a separate umbilical supplies control, instrumentation, communications, video and any required electrical or hydraulic services.
The umbilical may be non-buoyant and managed on a rendering winch so that it follows the plough without creating excessive slack, drag or risk of fouling. Its submerged weight, stiffness, catenary, abrasion resistance and compatibility with the launch-and-recovery system are therefore critical. Fibron can develop the product around the actual plough configuration rather than assuming that it performs the same duty as a trencher main-lift cable.
Subsea crawler cables and umbilicals
Tracked crawlers used for excavation, cable and pipeline intervention, seabed preparation, inspection, mining or specialist tooling may pull, trail or repeatedly reposition their umbilical as they move. This can expose the product to local abrasion, crushing, sediment, snagging and tight changes in direction close to the vehicle.
Crawler systems may be electrical, hydraulic or electro-hydraulic. Where required, Fibron can combine power and communications cables with reinforced high-pressure hoses in one umbilical. Diameter, flexibility, bend radius, submerged weight and drag can be balanced so that the connection does not unnecessarily restrict traction, steering or working range.
Power, control, fibre optics and hoses in one construction
A purpose-designed trencher, plough or crawler cable may incorporate:
- high-voltage and high-current power conductors
- auxiliary, earth and drain conductors
- screened pairs or quads for control and instrumentation
- copper data, video and fibre-optic elements
- hydraulic or other compatible service hoses
- water-blocking layers, steel-wire armour or synthetic strength members
- abrasion-resistant outer sheathing
Not every application requires every element. Bespoke engineering allows the necessary components to be selected and arranged while controlling electrical interference, optical strain, hose behaviour, axial stiffness, torsion, finished diameter and manufacturability.
Fibron’s published constructions demonstrate the breadth of this capability, from comparatively compact electro-optical trencher cables with very high breaking loads to large crawler and mining umbilicals integrating hydraulic, electrical and optical services.
Designed for the winch, LARS and operating cycle
The umbilical must be compatible with more than the subsea vehicle. Drum core and flange dimensions, level-wind geometry, fleet angle, sheave diameter, slip rings, tension control, rendering or heave-compensation settings and overboarding equipment can all influence the design.
For a new system, early collaboration allows the cable, terminations and handling equipment to be developed together. For a replacement or upgrade, Fibron can work within the constraints of an existing winch and machine interface while assessing opportunities to improve power capacity, data performance or mechanical protection. Important design inputs include:
- operating depth and deployed length;
- voltage, current and motor-starting duty
- communications protocols and optical-fibre count
- working, deployment and peak tensions
- drum, level-wind and sheave geometry
- minimum static and dynamic bend radius
- anticipated deployment and recovery cycles
- hose medium, bore and pressure
- electrical, optical, mechanical and hydraulic interfaces
- temperature, seabed conditions and chemical exposure
Considering these factors at the beginning of the project helps avoid a cable that is electrically suitable but incompatible with the winch, sheaves, terminations or operational method.
Protection against mechanical and environmental damage
Mobile seabed operations combine dynamic handling with a high risk of external damage. The cable may experience repeated reeling, reverse bending, changing tension, twist, clamp loads, impact and contact with abrasive sediment or equipment structures.
Balanced galvanised steel-wire armour can provide tensile capacity, crush resistance and external protection while helping to manage torque and rotation. Synthetic reinforcement may be considered where lower weight or different stiffness characteristics are important. Sheath and bedding materials can be selected for seawater resistance, hydrolysis performance, abrasion, oils, chemicals and the required operating temperature.
The mechanical termination is part of the design, not an accessory added afterwards. Armour bodies, hang-offs, pull-in heads, bend stiffeners, bend restrictors, electrical and optical connectors, hose fittings and hydraulic couplers can be coordinated with the cable so that loads and services pass safely into the machine and deck equipment.
Qualification and factory acceptance testing
Fibron can develop a qualification programme around the risks and duty cycle of the actual trenching spread. Depending on the product, testing may include:
- reeling and unreeling
- cyclic bend or bend-over-sheave fatigue
- tensile and break-load testing
- torque and rotation measurement
- crush and clamp testing
- bend-stiffness assessment
- termination-load verification
Electrical verification can include conductor and insulation-resistance measurements, high-voltage withstand, partial-discharge evaluation and voltage-breakdown testing where appropriate. Fibre-optic continuity and attenuation, hose proof-pressure and leak testing, termination testing and a complete functional factory acceptance test can also be incorporated.
Testing can follow a customer-specific specification or an applicable recognised standard. Inspection and test plans, qualification procedures, test reports and manufacturing records can form part of the project package.
Prototype, replacement and production manufacture
Subsea burial and intervention equipment is frequently modified for a particular project, soil condition, water depth or vessel spread. A new cable construction may therefore need to be evaluated alongside the machine, winch, connectors and deck equipment before the final production design is approved.
Fibron’s flexible manufacturing capability supports prototype lengths, one-off umbilicals, qualification samples and production requirements. A prototype can be used to assess finished diameter, flexibility, handling, winch behaviour, electrical and optical performance, hose functionality and termination interfaces.
Fibron can also support installed products through technical advice, testing, repair, re-termination, integration assistance and project-specific spares.
By combining cable and umbilical design, manufacture, termination and testing within one specialist organisation, Fibron helps equipment manufacturers, system integrators and offshore contractors reduce interface risk and develop a connection that is practical to manufacture, deploy and operate.
Frequently asked questions
What does a subsea trencher umbilical carry?
A trencher umbilical may carry high-voltage power, auxiliary power, control signals, telemetry, video and fibre-optic communications. Depending on the deployment system, it may also provide substantial tensile strength and mechanical protection.
Is a cable plough umbilical the same as a tow cable?
Not necessarily. Many plough spreads use a dedicated tow wire for the principal towing load and a separate control or utility umbilical. Other arrangements combine functions. The design should be based on the actual tow, launch-and-recovery and rendering system.
Can a crawler umbilical include hydraulic hoses?
Yes. Fibron can manufacture electro-hydraulic umbilicals combining reinforced hoses with power, control and communications cables. Hose pressure, medium, collapse resistance, flexibility and end fittings are considered alongside the cable components.
Can high-voltage power and fibre optics be combined in one trencher cable?
Yes. Power conductors, control elements and optical fibres can be integrated into one electro-optical construction. The cross-section must be engineered to protect the optical elements from strain and pressure while maintaining electrical insulation, mechanical strength and acceptable diameter.
Can Fibron manufacture a replacement for an existing trencher or plough umbilical?
Fibron can develop replacement and upgraded cables around the available technical information, equipment interfaces, winch capacity, bend limits, connector requirements and operating duty. Where appropriate, a prototype or qualification length can be manufactured and tested before final production.
Discuss Your Trencher, Plough or Crawler Cable Requirement
If you are developing or operating mobile subsea equipment and need a bespoke cable or umbilical, please get in touch with Fibron.
