Electrical Services for Container Ships
Reefer sockets, hold fans, ballast pumps and the bow thruster all draw from the same electrical plant, while the reefer share changes with each cargo mix. We troubleshoot, modify and extend the distribution behind those loads, and engineer the ship-side shore connection that lets the vessel stop her auxiliary generators at berth.
What container ship owners call us about
Most calls start with a breaker that keeps opening, equipment that will not stay online or a new load the ship now has to carry. We trace the problem through the distribution before deciding what needs to change.
- 01
Reefer circuits that trip
A reefer board trips with a full deck of boxes connected, or a socket group loses supply after rain or wash-down. We check the actual connected load, insulation resistance on deck cables and sockets, breaker ratings and settings, and the condition of outlets and plugs before deciding what needs repair.
- 02
More reefer sockets than she was built with
A new trade calls for more reefer slots than the ship has sockets for. That means new outgoing ways or a new distribution board, sometimes a transformer, and a check that the switchboard section, the generators and the power management can carry the extra load at sea and in port.
- 03
Generators that will not share the load
With a heavy reefer load running and the bow thruster starting, generator sets can hunt, share unevenly or trip on reverse power. We check governors, voltage regulators, load-sharing and power-management settings, together with generator protection, then verify the plant under representative operating conditions.
- 04
Starters and drives out of production
Ballast-pump starters, hold-fan starters and thruster drives may date from the original build. When a unit can no longer be supported, we check the motor, supply, protection, control signals and the effect of the replacement on the existing switchboard before integrating the new equipment.
- 05
A shore connection for the 2030 rules
From 1 January 2030, FuelEU Maritime requires container ships above 5,000 GT to take their whole electrical demand from shore whenever they stay alongside for over two hours in a port covered by AFIR Article 9, save for a short list of exceptions. On board, the shore supply needs its own incoming breaker on the main switchboard, a transformer if shore and ship voltages differ, a way to handle the cable, and interlocks that stop it being paralleled with the running generators outside a controlled transfer.
Where a reefer's power comes from
A plugged-in box is the last link in a chain that starts at the generators. A change at one point has to be checked against the equipment and protection upstream of it.
- 01
Generators
Running capacity
How many sets have to run for a given reefer count in port and at sea, how they share load, and what the power management does when a large consumer starts.
- 02
Main switchboard
The sections feeding the cargo
The breakers and busbars that supply the reefer distribution, the available fault level and how the protection is coordinated. The board work itself is covered under switchboards and power distribution.
- 03
Reefer transformers and boards
Distribution across the bays
Transformers where the socket voltage differs from the main busbar, and the boards that split the supply across holds and deck bays.
- 04
Sockets and plugs
The deck end
Outlets, cables and plugs in the holds and on deck are exposed to weather, wash-down and rough handling, so they are a natural place to investigate when insulation resistance falls.
- 05
Monitoring and alarms
What the crew sees
Reefer monitoring where fitted, together with power-management and alarm points, is where the distribution meets automation and control.
Adding sockets, a transformer or a large drive at one point means checking the running generators, the switchboard section and the feeder above it before anything is ordered.
OOCL Montreal: shore power delivered within a yard period
In 2026 Orion Marine delivered the ship-side AMP electrical scope on OOCL Montreal, a 4,402 TEU container ship, at Sefine Shipyard in Türkiye. The work was carried out within a yard period that also included docking and propulsion-efficiency work, and the vessel left with the shore connection commissioned. This is Orion's documented container-ship reference, specifically for the ship-side shore-power scope.
See the OOCL Montreal case studyWhat we ask for first
These details help separate work that can be done during a port call or while sailing from work that needs a longer isolation window or the next docking.
- Single-line diagram and the reefer distribution layout
- Number of reefer sockets, and how many are usually in use
- Generator ratings and how the power management is set up
- Spare ways and space in the sections that feed the cargo
- Makes and age of the starters and drives involved
- The rotation, the next long port stay and the next docking
Planning the work around a liner rotation
A liner schedule leaves narrow windows for attendance and isolation, so the work is split around the vessel's actual calls and docking plan.
- Fault-finding and surveys during a port call
- Cable pulling and preparation with a riding team at sea
- Connections that need a dead section during a longer port stay
- Switchboard, transformer and shore connection tie-ins in a docking
Related electrical services
- Generators, Motors & DrivesElectrical work on ship generators, motors and VFDs: load sharing, synchronising, AVR and protection faults, starters and obsolete drive replacement.
- Shore Power / AMPShore power (AMP / OPS) retrofits: load survey, HV shore connection to IEC/IEEE 80005-1, transformer, cable management, installation and commissioning.
- Testing & CommissioningElectrical testing and commissioning on vessels: insulation and continuity tests, controlled energisation, protection and interlock checks, running under load.
Container ship electrical work
- Can the reefer distribution be worked on while the ship trades?
- Some of it can. Fault-finding, insulation testing and preparatory cable work may fit into port calls or a riding-team passage. A new feeder or a main-switchboard change needs the affected section isolated, so that work is planned for a suitable port stay or docking window.
- Is shore power the only container ship work you do?
- No. OOCL Montreal is Orion's documented container-ship reference and its scope was shore power. Orion's wider marine electrical services include switchboard modifications, starters and drives, generator and load-sharing faults, automation interfaces, and testing and commissioning.
- Do changes to the reefer distribution need class approval?
- It depends on the change and on the ship's class society. Added sockets, a transformer or a new switchboard section usually mean revised drawings and load calculations. Where the society requires them for review, we prepare them for submission and allow for that review in the plan.
Electrical work coming up on a container ship?
Send the vessel details, rotation and the fault or modification required. We will identify what can be handled during a port call or while sailing, and what needs a longer isolation window or docking.