Common issues
- Rudder angle feedback transmitter drift or failure causing incorrect rudder angle indication
- Follow-up (FU)/Non-follow-up (NFU) mode switchover faults
- Control panel/touchscreen failure or lock-up requiring changeover to backup control
- Communication link fault between the bridge control panel and the steering gear room unit
- Solenoid valve or hydraulic control signal fault causing sluggish or erratic rudder response
- Power supply/UPS fault affecting redundant control channels
- Software/firmware faults after a power interruption requiring reset or reload
Inspection checklist
- Test changeover between main and emergency/local steering control per SOLAS steering gear test requirements
- Verify rudder angle indicator agreement between the bridge repeater and actual rudder position at the steering gear
- Test follow-up and non-follow-up steering modes
- Check alarm functions (power failure, low hydraulic level/pressure, phase failure) at the control panel
- Verify communication between the navigating bridge and steering gear compartment (dedicated phone/alarm)
- Check backup power supply/UPS battery condition and changeover
- Inspect control panel connectors, cabling and cabinet seals for corrosion
- Confirm a software/parameter backup exists and matches the as-installed configuration
Service intervals
| Steering gear changeover and function test | before departure per SOLAS Ch. V, in addition to the 12-hourly test at sea |
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| Rudder angle transmitter calibration check | per running hours or per the class survey interval - confirm against the specific installation's maintenance plan |
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| UPS/backup battery test and replacement | capacity check annually, replacement typically every 3-5 years depending on battery type |
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| Software/configuration backup verification | after any software update or control system fault, and at each planned maintenance round |
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Typical intervals for this design class, not the manufacturer’s figures for your model. The manufacturer’s manual is binding.
Critical spares
- Rudder angle transmitter/feedback unit
- Control panel/display unit
- UPS battery set
- Control system boards/fuses as listed in the maker's spare parts list - Kongsberg-specific, no generic substitute
- Communication cabling/connectors between bridge and steering gear room
Safety
- Loss of steering control is a critical safety failure - crew must be drilled on immediate changeover to emergency/local (trick wheel) steering
- High-pressure hydraulic steering gear presents injection and crush hazards - isolate hydraulics before working on associated control linkages
- Do not disable redundant control channels for testing without a clear plan to restore primary control
- Electrical work on the control cabinet requires isolation and lockout per the vessel's electrical safety procedure
Class survey
Steering gear control systems fall under SOLAS Ch. II-1 Reg. 29 testing requirements and class Continuous Machinery Survey; surveys check function tests of main/auxiliary steering gear changeover, alarms, and bridge-to-steering-compartment communication, plus records of the required before-departure and periodic at-sea tests.
Estimated lifetime: Not expressed in running hours. Control system electronics are typically supported for a defined obsolescence window, often around 10-15 years, before the maker recommends an upgrade - confirm against Kongsberg's current product life-cycle statement for the Mcon range.