HydroPlow Mobilisation for Prysmian Monna Lisa
HydroPlow Spread Mobilisation — Port of Middlesbrough
Project Overview
MJR Power & Automation delivers HydroPlow Mobilisation on Prysmian's Monna Lisa
Deck and below-deck power distribution, step-down transformers and HPU supplies, installed at the Port of Middlesbrough ahead of the vessel's next cable-laying campaign.
Monna Lisa operates as part of Prysmian Group's fleet, equipped for complex offshore cable installation, trenching and burial in support of major interconnector and offshore wind projects.
Prysmian Group contracted MJR Power & Automation to carry out the electrical installation required to mobilise a HydroPlow spread aboard her. The HydroPlow lays and buries cable in a single pass — one operation instead of two, which is where the time and cost saving in cable installation comes from, and which places a set of specific demands on the vessel's power.
The work was carried out at the Port of Middlesbrough, Steel River Quay, and covered the provision and integration of power distribution systems supporting the spread both below deck and on deck.
Project significance A plough spread arrives as a collection of separate items - the plough itself, its umbilical winch and hydraulic power unit, a control van, a deck shelter. None of them is useful until it is powered, and none of them was designed around this particular vessel's electrical system. The mobilisation is the work of making them one installation.
The challenge
Several separate items, one electrical system.
The plough's umbilical winch hydraulic power unit, the control van and the deck shelter all needed supply, each with its own requirements, none of them originally matched to this vessel.
Both below deck and on deck.
The distribution had to reach equipment in the machinery spaces and equipment exposed on the working deck, with the routing, containment and penetrations that implies.
Voltages the vessel did not already provide.
Additional 230V supplies were required for the spread, which meant step-down transformers rather than simply extending existing distribution.
A fixed sailing date.
The mobilisation was completed ahead of the vessel's next cable-laying campaign, so the work was bounded by the date she was due to sail rather than by the scope itself.
Scope of Work
Turnkey Vessel Electrical Installation for the HydroPlow Spread
The mobilisation included:
- Power supply to the control van, deck shelter and umbilical winch hydraulic power unit for the plough
- Installation of 230V and 440V distribution boards for the additional deck equipment
- Installation of a 25kVA 440V/230V transformer for the additional 230V supplies
- Installation of three stainless steel junction boxes, to the client's specification
Scope of work:
- Power distribution, installation and termination across the vessel's MV, 440V and 230V networks
- Design, build, installation and commissioning of deck power distribution systems
- Integration of transformers for step-down supply to 230VAC networks
- Cable management design and installation, including design of new ladder racks and cable penetrations
- Installation of deck equipment, including hydraulic power units for the HydroPlow
Solutions Delivered
The Distribution — New boards for new equipment
230V and 440V distribution boards were installed to serve the additional deck equipment, designed, built, installed and commissioned as part of the scope rather than adapted from what was already aboard. Cable management was designed alongside them, including new ladder racks and cable penetrations for the routes the spread required.
The Transformers — Supplies the vessel did not have
Step-down transformers were integrated to provide the additional 230VAC supplies the spread needed, taking 440V from the vessel's existing distribution and delivering it at the voltage the mobilised equipment required.
The Plough Spread — Powering each element
Supplies were provided to the control van from which the plough is operated, the deck shelter, and the hydraulic power unit driving the umbilical winch. The HPUs for the HydroPlow were installed as part of the deck equipment scope.
The HydroPlow lays and buries cable simultaneously. Everything above exists so that a single pass does the work of two, which is what makes the spread worth mobilising in the first place.
The Detail — Stainless steel junction boxes to specification
Three stainless steel junction boxes were installed to the client's specification. It is a small item and it is worth keeping, because it shows a client with a view on how the work should be done and a contractor building to it rather than to their own standard.
Delivery & Approval
Completed to Client Specification at Steel River Quay
All installations were completed to the client's specifications, supporting safe and efficient operation of the HydroPlow system. The electrical infrastructure delivered reliable power distribution across all HydroPlow components, and the mobilisation was completed ahead of Monna Lisa's next cable-laying campaign.
Technical Summary
- Client Prysmian Group.
- Vessel Monna Lisa — cable installation, trenching and burial vessel
- Vessel role Interconnector and offshore wind cable projects
- Sector Offshore Wind; Offshore Construction & Subsea
- Spread mobilised HydroPlow — simultaneous cable lay and burial
- MJR scope Turnkey vessel electrical installation for the mobilisation
- Location Port of Middlesbrough, Steel River Quay
- Distribution boards 230V and 440V, for additional deck equipment
- Transformers 25kVA 440V/230V
- Supplies provided Control van; deck shelter; umbilical winch HPU
- Deck equipment HPUs for the HydroPlow
- Cable management New ladder racks and cable penetrations, designed and installed
- Additional Three stainless steel junction boxes to client specification
- Coverage Three stainless steel junction boxes to client specification
- Coverage Below deck and on deck
Project Outcomes
The HydroPlow spread fully supplied
Reliable power distribution across every component of the spread — plough, umbilical winch HPU, control van and deck shelter.
Completed ahead of the campaign
The mobilisation was finished before the vessel's next cable-laying campaign, which is the only deadline that matters on work of this kind.
Built to the client's specification
Including the detail items, delivered as the client wanted them rather than as the contractor would have chosen.
New distribution capability retained aboard
Distribution boards, transformers, ladder racks and penetrations remain on the vessel, so future mobilisations start from a better position than this one did.
A third Prysmian vessel
Following the Ulisee and Barbarossa I, and against a stated history of multiple earlier mobilisations.
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