Autopilots, magnetic compasses and deviation work in Busan
NAVION installs, tunes and repairs autopilots, interfaces gyro, satellite and fluxgate heading sensors, and overhauls and adjusts magnetic compasses on vessels calling at Busan. Work is planned around the port call: bench-type jobs and steering checks are done alongside, and the swing and sea trial are taken when the vessel is turning. Every adjustment ends with a signed, dated deviation card in the wheelhouse.
Steering and heading are the two systems a bridge crew cannot work around. When the autopilot drops out or the compass card hangs, the vessel is on hand steering for the rest of the voyage. We install, tune and repair autopilots, interface heading sensors, overhaul magnetic compasses and carry out compass adjustment in Busan: alongside at Gamcheon fishing port, in the Yeongdo repair yards, at Busan New Port, and at other yards on request.
Most of this fits inside a port call. Overhaul, refill, card replacement, feedback and drive work and the alarm checks are done alongside; the swing and the autopilot sea trial both need the vessel under way, so they are normally taken during shifting between berths, on departure or at anchorage, and agreed with the master when the job is booked.
What the job includes
- Autopilot supply, installation and commissioning — New unit or like-for-like replacement: control head, distribution unit, power supply, mounting and cabling, then full parameter setup before the vessel sails.
- Rudder feedback and drive unit work — Feedback transmitter alignment and midship zero, linkage geometry and backlash, solenoid or reversible pump interface, hard-over to hard-over timing check.
- Heading sensor and satellite compass interfacing — Gyro step or synchro takeoff, NMEA HDT/THS wiring, baseline alignment and offset entry, heading-lost behaviour and talker priority on the pilot input.
- Autopilot tuning and sea trial — Rudder gain, counter rudder, weather and off-heading settings tried on real headings, with zigzag and course-keeping checks logged before handover.
- Magnetic compass overhaul and bowl refill — Fluid top-up or full refill, bubble removal, seal and expansion bellows inspection, leak tracing, cleaning of the dome and lubber line reset.
- Compass card, pivot and gimbal replacement — Card assembly change for sticking or slow-settling cards, worn pivot or chipped sapphire cap, gimbal freeing and binnacle lighting and dimmer repair.
- Compass adjustment and deviation card — Corrector magnets, heeling bucket, quadrantal spheres and Flinders bar set, ship swung, residual deviation tabulated and a signed deviation card issued.
- Steering alarm and NFU/FU control checks — Off-course and heading-monitor alarms, power failure alarm, changeover at each steering station, rudder limit and emergency steering position tested.
- Compass and binnacle relocation or re-siting — Moving or re-mounting a binnacle after wheelhouse work, checking magnetic clearance from new equipment, then re-swinging and reissuing the card.
- Fault finding on existing steering systems — Wandering course, hunting rudder, no-response in auto, drifting heading: signal tracing from sensor to drive with the wiring and pilot logs checked.
Timing
Ranges below are typical for work alongside in Busan and are not a guarantee. Access to the steering gear room, the state of the existing wiring and the vessel's own schedule move them more than anything we control. Two steps cannot be done at a berth — the compass swing and the autopilot sea trial — so both are planned into a shift, a departure or a stay at anchorage.
- Magnetic compass overhaul alongside
- typically 3-6 hours
- Autopilot replacement and setup
- typically 1-2 days
- Heading sensor interfacing
- typically 3-6 hours
- Compass swing and deviation card
- typically 1-2 hours turning
- Steering alarm and control checks
- typically 2-4 hours
What we need from the vessel
- Access to the wheelhouse, the binnacle and the steering gear room, with the steering gear available on power for rudder movement tests.
- Ship's supply confirmed at the distribution board for the autopilot and heading sensors, and agreement on when it may be isolated.
- A crew member on the helm and in contact with the steering gear room while rudder and changeover tests are run.
- Permission to move the rudder alongside, or a slot during shifting or departure if the berth does not allow it.
- Existing wiring diagrams, equipment manuals and the previous deviation card, if the vessel still holds them.
- The vessel's schedule as early as possible, so the swing can be planned into a shift, departure or anchorage stay.
Documents issued
- Deviation card, signed and dated, for the steering position, with a copy for the ship's file
- Record of correctors fitted and their final positions, including heeling magnet and Flinders bar
- Autopilot commissioning record: gains, rudder limits, alarm settings and sea trial observations
- Interface record for heading sources, showing wiring, sentence types and verified offsets
- Service report listing parts fitted, work carried out and any outstanding recommendations
Photographs of this work are being prepared.
Frequently asked
Can the compass be adjusted while we stay alongside?
Only partly. Overhaul, refill, card and pivot replacement, corrector inspection and binnacle work are all done at the berth. Reading deviation requires the vessel to turn through headings, so the swing is normally taken while shifting between berths, on departure, or at anchorage. We agree that step with the master at booking and issue the card once the swing is complete.
How often should the magnetic compass be swung?
Flag and class requirements differ, so check what your administration expects. In practice a swing is due when the card is old, when deviation found on passage no longer matches the card, after a drydocking or major structural work, after welding or a lightning strike, and whenever new equipment, a mast, bracket or cable run has been fitted near the binnacle.
The autopilot steers well in calm water but wanders in a seaway. Is that a setting?
Often, but not always. Rudder gain, counter rudder and the weather or deadband setting are the first things to look at, and they need to be checked on the actual heading and loading condition. Slack in the feedback linkage, a mis-scaled feedback transmitter, a slow drive unit or noisy heading data will produce the same symptom, so we trace the signal path as well as the menu.
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Send the ETA, berth area and what is fitted now: autopilot make, heading source and the date of the last deviation card. We confirm scope, parts and a realistic time alongside.