BELFOR Restores Oil-Contaminated Electrical Systems Aboard a Large Offshore Vessel

Large Offshore Construction Vessel with Oil-Contaminated Electrical Systems

The vessel was a large offshore construction vessel whose electrical infrastructure, including its main power distribution, transformers, and heavy-lift crane control systems, became contaminated with oil, prompting a call to BELFOR Singapore for a full damage assessment and decontamination.

Oil Contamination Impacting Critical Marine Electrical Infrastructure

The scale of the oil contamination was substantial, extending across the vessel’s core electrical systems. Affected equipment included four transformers supporting different parts of the power network, the main 6.6kV switchboard along with 690V and 380V distribution boards, a heavy-duty drive system and sine filter rated for 150 metric tonnes (part of the vessel’s crane or winch operations), an air conditioning unit, several drive modules, five air circuit breakers, and five control valves.

With contamination present across such a wide range of critical systems, both power distribution and heavy machinery control were at risk if the equipment wasn’t properly restored.

Electrical Decontamination and Restoration of Offshore Power Systems

The client engaged BELFOR to carry out a full decontamination of the affected electrical panels, switchboards, transformers, circuit breakers and associated modules, combining on-site and workshop-based cleaning to restore the full scope of equipment. BELFOR’s Marine Team response included:

• On-site cleaning of fixed installations, including cable trunkings, cables, terminals and panel frames, using alkaline-based cleaning agents, pressure washing, and repeated rinsing until fully residue-free.
• Insulation resistance testing of all four transformers before and after cleaning to verify improved performance.
• Full inspection and cleaning of the main switchboards, including removal and cleaning of high-voltage breakers and busbars.
• Controlled drying of cleaned panels and transformers using heated, enclosed tenting.
• Precision cleaning of sensitive components, including inverter drive modules and air circuit breakers, at BELFOR’s workshop under controlled conditions.
• Replacement of a small number of worn parts, such as fuses, terminal blocks, timers, indicator lights, insulation and gaskets.

Every restored system was reassembled and returned to its original configuration before being reinstalled aboard the vessel.

Successful Recovery of Transformers, Switchboards and Crane Control Systems

BELFOR successfully decontaminated and restored the full scope of affected equipment, including all four transformers, the main switchboards, drive systems, circuit breakers and associated modules, returning them to their pre-incident condition. Insulation resistance testing confirmed that transformer performance had measurably improved following the cleaning process. The entire decontamination process was completed in under two weeks, after which the client formally confirmed that the work delivered was complete and satisfactory.

Offshore Electrical Restoration Following Large-Scale Oil Contamination

When oil contamination threatened a wide range of critical electrical systems aboard a large offshore vessel, from power transformers and switchboards to heavy-lift crane controls, BELFOR responded with a highly coordinated on-site and workshop decontamination procedure.

By combining specialist cleaning, controlled drying, component-level precision cleaning and electrical testing, BELFOR was able to restore the affected equipment to its pre-incident condition while addressing multiple systems within a single recovery program.

The entire decontamination process was completed in under two weeks, with insulation resistance testing confirming measurable improvement in transformer performance following cleaning. The successful outcome demonstrated how engaging a certified restoration specialist can help recover critical electrical assets following oil contamination, saving recovery costs and shortening downtime.

This project reinforces BELFOR’s capability to manage complex, large-scale electrical recovery projects in offshore and marine environments, where the reliable restoration of critical systems is essential to returning equipment and operations to service.