Marine Automation & Control Systems
A level signal is correct at the tank but missing in the control room. A new pump needs remote start, stop and alarm indication. A generator does not respond to the power management system. We trace and integrate the circuits, signals and interfaces between the machinery and the people operating it.
Every control fault sits somewhere on this path
A signal leaves a field device, passes through wiring and I/O into the control system, and appears as an alarm, a reading or a command. Fault finding and integration both start by identifying which part of that path is failing or being changed.
- 01
Field device
Sensor, switch or actuator
Pressure and temperature transmitters, level and limit switches, solenoids and actuators. We check the device first: its supply, loop current or contact state, and whether its signal matches what the control system expects.
- 02
Wiring and I/O
Cable, terminals, I/O channel
A missing signal is often found between the device and the controller: a damaged cable, loose terminal, blown I/O fuse or failed channel. We measure at each point in sequence until the signal is lost, rather than replacing I/O cards on suspicion.
- 03
Control
Control circuit or controller
This is where start permissives, interlocks, sequences and standby changeover are decided. We work from the drawings and the cause-and-effect list where one exists, and document the actual logic when the drawings no longer match the vessel.
- 04
Alarm and monitoring
What the system shows
The alarm list, mimic pages and trends in the control room and on the bridge. A signal that reaches the controller can still be scaled wrongly, mapped to the wrong tag or inhibited. We compare the value on the screen with the value at the device.
- 05
Operator command
Commands back to the equipment
A start, stop or setpoint command has to pass from the operator interface through the control system to the starter, drive or valve. If local control works but remote control does not, we trace that command path.
Integration follows the same path. New equipment may need a field device, cable cores, spare I/O, control logic, alarm indication and remote commands. If one part is missing, local operation may still work while control-room indication or remote control remains incomplete.
What owners call us about
These are typical control and automation faults. We trace the signal, supply and logic before deciding what needs to be changed.
- 01
A signal present in the field but missing on the screen
The transmitter reads correctly at its own terminals and the monitoring system shows a fault, or nothing. We follow the signal terminal by terminal to the point where it disappears: cable, junction box, barrier, I/O channel or configuration.
- 02
New equipment that has to be controlled remotely
A pump, compressor or treatment unit may arrive with its own local panel. To control it remotely and bring its status and alarms into the existing system, it needs I/O, signal cabling, interlocks and tested logic. This is often part of an installation.
- 03
A generator that does not follow the power management system
The set starts by hand but will not start on demand, take load or stand down when the PMS asks. We check start and stop commands, breaker status, and load and speed signals at the interface with the PMS. Generator-side checks are covered under generators, motors and drives.
- 04
Alarms that come and go
An alarm that appears in heavy weather, at one engine speed or only when another consumer starts points to wiring, screening or a shared supply. We look for what changes at the moment it appears.
- 05
Control hardware the maker no longer supports
Relays, controllers, I/O modules or operator panels may reach a point where spares and maker support are no longer available. A failed component may be replaceable without rebuilding the whole system if its signals and logic are recorded first. Larger replacements are planned as a retrofit.
- 06
An interlock that has been bypassed
An interlock may have been bypassed after an unexplained trip so the vessel could continue operating. We find why it operated, restore the intended circuit and test the interlock before the temporary link is removed.
Adding to a control system that is already running
Control systems on vessels in service often differ from their original drawings. Signals are added, spare channels get used and temporary links can remain in place. Before allocating new I/O, we compare the installed system with the drawings: spare channels of the right type, spare cores in multicore cables, cabinet space and power-supply capacity.
The signals are then listed one by one with their type, range and direction, and each is assigned a terminal, channel and tag. That list becomes the basis for the wiring and the tests. Where the change reaches proprietary maker software, any required maker involvement is identified before modification.
Each signal is proven end to end before handover: the device is operated or simulated and the result is read at the screen, then the command is sent from the screen and watched at the device. The full sequence is described under testing and commissioning.
Systems and interfaces in scope
Electrical and control work on the systems that start, stop, protect and report on the vessel's machinery.
- Alarm and monitoring systems
- Machinery control circuits and local control panels
- Power management system interfaces
- Generator start, stop and breaker control
- Pump, fan and compressor start and stop logic
- Remote control and indication
- Signal and control cabling
What helps before we board
These details can narrow a control fault to one part of the signal path before attendance.
- The alarm list, or a photo of the alarm as displayed
- Control and I/O drawings, and loop diagrams if they exist
- When the fault appears and what else is running at the time
- Maker and type of the control system
- Recent changes to the equipment or its wiring
Where automation connects to other electrical work
- Generators, Motors & DrivesElectrical work on ship generators, motors and VFDs: load sharing, synchronising, AVR and protection faults, starters and obsolete drive replacement.
- Testing & CommissioningElectrical testing and commissioning on vessels: insulation and continuity tests, controlled energisation, protection and interlock checks, running under load.
- Installation & OutfittingElectrical installation on vessels in service: new equipment, cabling and transits, switchboard connections, motors, drives and controls, then commissioning.
- Retrofit & ModernizationShip electrical retrofits: obsolete drives and switchboard parts replaced, distribution and controls modernised, shore power integrated into the existing plant.
Practical questions before control work
- Can signals be added without replacing the control system?
- Usually, if there are spare channels of the right type and room for additional I/O. We confirm that on board before proposing the change. If the system is full or its hardware is no longer available, we set out what a replacement would involve.
- Does it matter who made the control system?
- Much of our work is on the electrical side: field devices, wiring, I/O, control circuits and interfaces. That can often be handled independently of the maker. Changes inside proprietary maker software may need the maker's involvement, and we identify that at the start.
- Can a control fault be found while the vessel is trading?
- Often. Some signal tracing can be done while the system remains in service, and intermittent faults are easier to reproduce when the conditions that trigger them are present. Any work that requires isolation is planned into a suitable port call or shutdown window.
Control fault or signal to add?
Send the vessel details, system type and the fault or change required. An alarm list and control drawings help us assess the job before attendance.