MMC Diving Services

"Since 1964"

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  • HV Cable Installation

    MMC Diving Services complete subsea cable installation

    MMC's 24 man team, including barges, crane, divers, cable pullers, and a multicat complete the subsea cable installation of x14 HV cables, testing and surveying in Portsmouth Harbour.


Client: DIO - HMNB Portsmouth

Contractor: Volker Stevin

Duration: 6 days

Date posted: 10-05-2019

MMC fabricated and installed two large 700kg stainless steel racks to accommodate the new requirements for subsea cables between Sheer Jetty and Victory Jetty across the entrance to No1 Basin within HMNB Dockyard Portsmouth. The work was to complete the jointing between the two jetties, through a custom cable transit in the seawall at the end of both jetties. This had to be sealed prior to the next spring tide. The works had a very narrow window for completion and had to be timed around good weather.

The QEC HV Substation was completed in 2016 as part of the QEC Base Porting Infrastructure. The project's design was to house the powertrains for both the HMS Queen Elizabeth and the HMS Prince of Wales and as part of that project the electrical infrastructure for HMS Queen Elizabeth was installed along with the civil infrastructure for HMS Prince of Wales.

As the subsea cable contractor, MMC was expected to test each subsea cable individually prior to the joints being installed and after, as part of the quality control, to ensure the cable across the basin was undamaged during the installation. A detailed survey of the cable position and depth was then completed and handed to the client.

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