The South's Premier Provider of Marine Services

Visit our Offices

Burnley Wharf, Marine Parade, Southampton, SO14 5JF

Give us a Call

+44 2380 235205

Send us a Message

[email protected]

Office Opening Hours

Mon - Friday: 8AM - 4PM

The South's Premier Provider of Marine Services

24/7 Breakdown - +44 7766 311154

Text Us

Call Us

Latest News

09/10/26 By Keith Wilson

XV Patrick Blackett – Docking, Mast Replacement and Refit

59-day docking and refit programme incorporating aluminium fabrication, structural installation, marine electrical works and specialist lifting operations.

Project overview

IME Repair Services recently completed a 59-day docking and refit programme on XV Patrick Blackett at Portchester Ship Lift, working alongside Serco and the Ministry of Defence (MOD).

A major element of the project involved manufacturing and installing a new 7-metre aluminium mast and a 660 kg supporting goalpost structure spanning the vessel's bridge.

Mast fabrication at IME Southampton

Completed goalpost structure

The work brought together several of IME's core capabilities, including aluminium fabrication, coded welding, marine electrical installation, heavy lifting, marine transportation and project coordination.

With fabrication undertaken at IME's Southampton facility and installation completed at Portchester, the programme required careful coordination between the workshop, vessel and specialist contractors.

The vessel was successfully relaunched on 16 September 2026, with the docking programme completed on schedule.

Fabricating the new mast and goalpost structure

One of the largest elements of the project was the manufacture of two substantial aluminium structures:

A 7-metre mast weighing approximately 990 kg, incorporating three platforms for aerials, radar and communications equipment.

A 660 kg goalpost structure, designed to span the bridge and support the new mast installation.

Both structures were manufactured from class-approved aluminium, working to class-approved engineering drawings prepared by Houlder.

Fabrication took place at IME's Southampton facility, where a purpose-built, watertight temporary building provided a controlled working environment for the project.

Our coded welders used dedicated fabrication jigs, temporary bracing and planned welding sequences to maintain dimensional accuracy and minimise distortion throughout the build.

The fabrication scope also included ladders, handrails, mounting brackets and associated fittings.

With structures of this size and configuration, maintaining dimensional accuracy was particularly important to ensure the completed assemblies could be correctly positioned and secured during installation onboard.

Preparing the vessel and removing the existing mast

While fabrication progressed in Southampton, the docking programme at Portchester involved preparing XV Patrick Blackett for the structural and electrical works.

This included lifting the vessel out of the water, establishing safe access, providing shore electrical and fresh-water connections, and carrying out high-pressure washing of the underwater hull and propellers.

Before removing the existing composite mast, the electrical systems and associated equipment required careful isolation and disconnection.

Cabling was identified and withdrawn, while equipment designated for reuse was disconnected and protected.

The existing mast was subsequently removed using a planned crane lift, with controlled disposal of the redundant structure included in the project.

Transporting the new mast from Southampton to Portchester

With fabrication complete, the next stage was transporting the new mast to the vessel.

At 7 metres long and weighing approximately 990 kg, the structure required a planned lifting and marine transportation operation.

The mast was loaded by crane at IME's Southampton facility before being transported by barge to Portchester Ship Lift.

Barge transport to Portchester

Mast installation by crane

This formed an important link between the fabrication and installation phases, allowing the completed structure to be delivered directly to the docking location.

Once at Portchester, the installation team could begin positioning and securing the new structures onboard.

Installing the goalpost and new mast

The onboard installation involved preparing the structural interfaces, positioning and welding the new goalpost structure, and lifting the mast into its final position.

Both assemblies required dimensional checks and careful alignment before being secured at their specified fixing points.

The installation scope also included measures to prevent galvanic corrosion between dissimilar metals, together with access scaffolding and associated modifications to wheelhouse steps and handrails.

The work required coordination between IME's fabrication and installation teams, lifting contractors and other trades operating within the wider docking programme.

Marine electrical installation and equipment integration

Alongside the structural work, IME undertook the electrical installation associated with the replacement mast.

This included running and terminating mast cabling back to the bridge and communications room, together with the installation of cable trays, containment, junction boxes and cable transits.

Cable identification and terminations were undertaken in accordance with the relevant Parkburn documentation and equipment manufacturers' requirements.

The electrical scope also covered the reinstatement of retained equipment and installation provisions for radar, communications systems, navigation lighting and associated fittings.

IME worked alongside specialist equipment engineers to coordinate the electrical interfaces, with final connections to the specialist radar unit remaining within the equipment supplier's scope.

Painting, inspection and testing

The new mast and goalpost were prepared and painted at Southampton before transportation, with provision for coating touch-ups following installation onboard.

Where required, internal deckhead and bulkhead panels were removed to provide installation access and accommodate fire-watch arrangements, before subsequent reinstatement.

Quality assurance formed an important part of the fabrication and installation programme.

The project quality requirements included material traceability, welding qualifications, dimensional inspections and non-destructive testing of fabrication and installation welds.

Dye-penetrant testing of the fabrication welds was specified within IME's scope, together with the relevant inspection and quality records.

The electrical testing scope covered power distribution, navigation lighting, communications equipment, earthing, bonding and lightning-protection continuity.

Commissioning arrangements also involved coordination with specialist equipment engineers and radio survey support.

IME's scope included provision for supporting the customer-led inclining experiment with qualified rigging and slinging personnel, while Serco retained responsibility for class and authority engagement.

Coordinating the wider project

Delivering the programme required coordination across multiple locations, trades and specialist contractors.

IME managed the interfaces between workshop fabrication, marine transportation, structural installation and electrical works, alongside the wider vessel refit.

Supporting contractors included SWJ Maintenance, SES, Jarrett Scaffolding, GM Lifting and Williams Shipping.

Each stage needed to be coordinated around the vessel's docking schedule, from manufacturing and transporting the new structures through to their installation and the associated onboard works.

Project completion

The 59-day docking and refit programme was completed on schedule, with XV Patrick Blackett successfully relaunched at Portchester on 16 September 2026.

The project brought together substantial aluminium fabrication, specialist lifting and transportation, structural installation and marine electrical integration within a single coordinated programme.

From manufacturing the 990 kg mast and 660 kg goalpost in Southampton to installing the completed structures onboard, the work provides a practical example of the range of engineering services IME Repair Services can deliver for commercial and defence-sector vessels.

Completed mast and goalpost onboard

Completed mast platforms

To learn more about IME and the services we offer, contact us here

Client Testimonials

Thank you very much for all your efforts in carrying out the repairs on board our SD Northern River.

As always you all responded in an excellent manner and it is a pleasure working with you

Tom Cakebread

Serco

The falcon has finally managed to run up and test all systems this evening with everything going as planned; obviously we haven't been able to fully load up the deck belt but all looks good

Huge thank you to everyone involved over the last few days, it was all very last minute and I appreciate that you have had pre-existing work commitments to fulfil, so thank you very much for all the assistance